Home
Chapter Home
Jobs
Conferences
Fellowships
Books
Advertisement
Small bowel (small intestine)
Superpage - Nontumor
Revised: 8 January 2013
Copyright: (c) 2001-2013, PathologyOutlines.com, Inc.
Normal anatomy
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Extends from gastric pylorus to ileocaecal valve
● 6 meters long, divided into duodenum, jejunum, ileum
Duodenum:
● 25 cm long, from pyloric sphincter to ligament of Treitz, mostly retroperitoneal, fixed in position
● Common bile duct (CBD) and pancreatic duct enter second part of duodenum posteromedially at ampulla of vater
(eMedicine)
Jejunum:
● 240 cm long, 40% of remainder of bowel, begins at ligament of Treitz
● Has prominent circular mucosal folds (folds of kerckring) that increase absorptive surface
Ileum:
● 360 cm long, distal 60% of post-duodenal bowel
● Mucosa has transverse folds, prominent in proximal ileum, flat/absent at terminal ileum
Ileocecal valve:
● At end of small bowel
● 2 lip structure containing adipose tissue and lymphoid tissue
Lymph nodes:
● Duodenum drains to portal and pyloric nodes
● Jejunum and proximal ileum drain to mesenteric nodes and nodes around superior mesenteric artery, terminal ileum drains to ileocolic nodes
● Lacteals are lymphatic channels in villi for chylomicrons
Intestinal immune system consists of:
● Peyer’s patches in ileum (ovoid lymphoid follicles, partly mucosal and partly submucosal, in antimesenteric side of terminal ileum)
● Small intestinal goblet cells, which deliver low molecular weight soluble antigens from intestinal lumen to CD103+ lamina propria dendritic cells, which regulates development of T cells (Nature 2012;483:345)
● M (membranous) cells, part of follicle associated epithelia (MALT) in small bowel and colon, which transfer antigen macromolecules from lumen to lymphocytes
● T cells, usually CD8+ and scattered in surface epithelium
● Lamina propria contains CD4+ T cells and B cells
● Mucosa associated lymphoid tissue: lymphoid nodules, mucosal lymphocytes, appendiceal lymphoid follicles and mesenteric nodes
(Annu Rev Cell Dev Biol 2000;16:301,
RIKEN Research Center for Allergy and Immunology
Neuromuscular function:
● Anterograde and retrograde peristalsis mixes food and promotes maximal contact of nutrients with mucosa
● Colonic peristalsis prolongs contact with mucosa
● Peristalsis is mediated via myenteric plexus and autonomic innervation (sympathetic-thoracolumbar, parasympathetic-vagal)
● Also through interstitial cells of Cajal (pacemaker cells) and smooth muscle cells
● Vagal receptors are abundant in duodenum and scattered throughout wall
Diagrams
=========================================================================
Duodenum
M cells
Gross images
=========================================================================
Ileum and terminal ileum
Micro images
=========================================================================
Peyer's patches
Lymph nodes: lacteals
Normal histology
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 8 November 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
Layers:
● Mucosa, submucosa, muscularis propria (externa), subserosa, serosa
Mucosa:
● Contains villi with central blood vessels, lymphatics
● Layers are epithelium, lamina propria, muscularis mucosa
Villi:
● Short and stubby in duodenum, very tall in jejunum, intermediate height in ileum
● Contain microvilli
● Villus to crypt length is 3-5:1
● Lined by primarily columnar absorptive cells and goblet cells
● Usually 1 lymphocyte per 5 enterocytes
● Villi may be short and distorted next to lymphoid aggregates
● 4 normal villi in a row in a biopsy suggests normal villous architecture
● Each villus contains an arteriole with capillary network, veins and a central lymphatic with numerous nerve fibres
Absorptive cells:
● Have microvilli on luminal surface (brush border) and underlying mat of microfilaments (terminal web)
Microvillus:
● 1.5 to 2 µm in length and 100 nm in diameter
● PAS positive, actin-myosin complexes
Goblet cells:
● Occur in crypts and surface absorptive cells
● Decrease towards villus tip, increase in frequency along small intestine (most numerous in lower ileum)
● Columnar in shape, mucus droplet in supranuclear area, secretes mucus, ions and water
Crypts of Lieberkuhn:
● Lower 20% of epithelium, contain undifferentiated (immature) crypt cells, Paneth cells (have large, apical eosinophilic granules containing antimicrobial proteins), scattered goblet cells and endocrine cells
● Are surrounded by pericrypt fibroblast sheath
● Secrete ions, water, IgA, antimicrobial peptides into lumen
● Crypt cells take 3-8 days to migrate to surface
● Allows for rapid repair, but also causes these cells to be sensitive to radiation therapy and chemotherapy
Lamina propria:
● Contains loose connective tissue, lymphocytes, plasma cells, occasional eosinophils, macrophages, mast cells, neutrophils
Submucosa:
● Contains connective tissue, blood vessels, lymphatics, submucosal (Meissner’s) plexus
● Also Brunner’s glands in duodenum
Brunner glands:
● Submucosal mucous glands in duodenum, secrete bicarbonate ions, glycoproteins, pepsinogen II
● Resemble gastric pylorus mucous glands
Muscularis propria (externa):
● Inner circular and outer longitudinal layer, with myenteric (Auerbach’s) plexus between these layers
● Plexus also contains interstitial cells of Cajal (Am J Surg Pathol 2003;27:228), ganglion cells, fibroblasts
Serosa:
● Contains mesothelial lining, loose connective tissue
Endocrine cells:
● Similar to cells in pancreas, biliary tree, lung, thyroid, urethra
● Contain fine eosinophilic granules with secretory proteins
● Nuclei on luminal side of granules, not basal
Micro images
=========================================================================
Brunner glands
Crypts of Lieberkuhn
Enterocyte
Serosa
Villi
Duodenum
Jejunum
Congenital anomalies
Atresia/stenosis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Atresia: imperforate mucosal diaphragm or string like segment of bowel
● Stenosis: narrowing of lumen; less common
● Complications: perforation, meconium peritonitis, brown bowel syndrome
Etiology
=========================================================================
● Developmental failure, intrauterine vascular accidents, intussusceptions
Case reports
=========================================================================
● 46 day old male infant with multiple areas of jejunal atresia with apple peel deformity (twisted around an artery) associated with 22q11 abnormality
(Arch Pathol Lab Med 2000;124:880)
Additional references
=========================================================================
● World J Gastroenterol 2010;16:5716
Congenital anomalies
Diverticula (other than Meckel’s)
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
Duodenal:
● Present in 1-2%, usually solitary and congenital, may cause obstructive jaundice, pancreatitis, fistulas, hemorrhage, perforation
● Usually penetrate the pancreas
● May project into lumen like a polyp
Jejunal:
● Present in 0.3% to 1.4% of autopsies
● Three times less frequent than duodenal, but four times more likely to develop complications
● Usually proximal jejunum along mesenteric border
● Often multiple with thin wall
● Associated with diverticula elsewhere in GI tract
● Some are congenital but most are acquired
● Usually asymptomatic but may cause obstruction, hemorrhage, perforation, abscess, malabsorption or Vitamin B12 deficiency, possibly due to bacterial overgrowth in the diverticula
Case reports
=========================================================================
● 88 year old man with acute ulcerative jejunal diverticulitis (World J Gastroenterol 2008;14:6265)
Clinical images
=========================================================================
Jejunal diverticula
Congenital anomalies
Duplication
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Saccular to long, cystic structures which usually have shared muscular wall (so incomplete duplication)
● More common in ileum, near ileocaecal valve; rare in duodenum, where choledochocele (cystic or diverticular dilatation of terminal intramural portion of the common bile duct) is more common
● Present with abdominal mass, pain, vomiting and chronic rectal bleeding
● Associated with gastric heterotopia, but not associated with vertebral body abnormalities
Case reports
=========================================================================
● 51 year old man with adenocarcinoma arising in a cystic duplication (World J Surg Oncol 2012 Apr 10;10:55)
Treatment
=========================================================================
● Resect entire duplication and segment of normal bowel attached to it
Congenital anomalies
Ehlers-Danlos syndrome
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Defect of collagen synthesis, commonly causes hyperelasticity of skin and joints
● May cause spontaneous intestinal perforation and hemorrhage
● Perforations are most common in recto-sigmoid, small bowel perforations (normal or diverticulae) are less common
● Colonic perforation may be associated with abnormal myogenic activity and
Case reports
=========================================================================
● 53 year old woman with occult perforation of distal ileum (Cases J 2010;3:57)
Clinical images
=========================================================================
: Occult small bowel perforation in patient with Ehlers Danlos syndrome
Congenital anomalies
Enterogenous cysts
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Found in wall of small bowel, mesentery, posterior mediastinum or rectorectal space
● May be associated with vertebral body abnormalities
Micro description
=========================================================================
● Lined by respiratory, small intestinal or gastric epithelium
● Wall composed of irregularly oriented smooth muscle
Additional references
=========================================================================
● J Indian Assoc Pediatr Surg 2012;17:68,
J Pediatr Surg 2004;39:e5
Congenital anomalies
Gastroschisis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Congenital defect characterized by defect in anterior abdominal wall through which abdominal contents freely protrude (Wikipedia)
● Associated with younger mothers, alcohol and tobacco use, ibuprofen use during pregnancy (eMedicine #1, #2)
Congenital anomalies
Heterotopic gastric mucosa
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Mature gastric tissue in location where normally not found (i.e. small bowel)
● Discrete small nodules or sessile polyps, usually in duodenum (first and second part)
● May cause obstruction, diarrhea, ulceration, bleeding, perforation, intussusception, pain
(Pediatr Dev Pathol 2000;3:277)
● Presence in duodenum is associated with H. pylori infection and is probably not congenital
(Hum Pathol 2003;34:156)
Case reports
=========================================================================
● 50 year old man with duodenal polyp
(Case of the Week #124)
● 52 year old woman with jejunal mass
(Arch Pathol Lab Med 2003;127:506)
● 67 year old woman with gastric type adenoma
(Virchows Arch 1999;435:452)
Gross images
=========================================================================
Case of the Week #124
Figure 1
Micro description
=========================================================================
● Mature gastric tissue, usually fundic type mucosa with chief and parietal cells, lined by foveolar epithelium, with a full mucosal thickness, forming a mucosal island
● Divided into two subtypes, one lined by foveolar epithelium only and another foveolar epithelium along with fundic glands
● The former may be congenital or acquired (metaplasia) and latter is only congenital
(Int J Clin Exp Pathol 2012;5:46)
Micro images
=========================================================================
Case of the Week #124
Various images
Differential diagnosis
=========================================================================
● Gastric metaplasia: associated with chronic inflammation, duodenitis and H. pylori, only occupies part of mucosal thickness, typically no gross findings, no parietal cells (Braz J Med Biol Res 2007;40:897,
Dig Liver Dis 2002;34:16)
● Peptic ulcer disease: no goblet cells
Congenital anomalies
Heterotopic pancreas
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Also called adenomyoma, myoepithelial hamartoma (although without pancreatic tissue)
● Incidence of 1-14%, affects all ages but peaks in 4-6th decade
● Most common near ampulla of Vater; also stomach, jejunum
● May cause blockage of duct, leading to infection, cystic dilation and fat necrosis
● Usually incidental finding at surgery submitted for frozen section, but carcinoma may arise from pancreatic heterotopia (Arch Pathol Lab Med 1999;123:707)
Case reports
=========================================================================
● 39 year old woman with duodenal polyp (Case of the Week #226)
Gross description
=========================================================================
● Submucosal nodule, intramural mass
● Yellow-white, lobulated, 0.2 cm to 4 cm
● May have central mucosal dimple
Micro description
=========================================================================
● Widely separated pancreatic acini with minimally developed ducts, well formed acini may be seen
(JOP 2007;8:588,
Mod Pathol 2003;16:530)
● Pancreatic heterotopia may be total, only ducts, only acinar cells (exocrine heterotopia), only islet cells (endocrine heterotopia)
● Adenomyoma: predominance of pancreatic ducts with proliferation of thick smooth muscle bundles of the muscularis around the ducts (seen in periampullary region of the duodenum)
Micro images
=========================================================================
Various images
With acinar cell carcinoma
With ductal adenocarcinoma
Differential diagnosis
=========================================================================
● Well-differentiated adenocarcinoma
● Neuroendocrine tumor from endocrine heterotopia
● Cystic change in pancreatic heterotopia from duplication
Additional references
=========================================================================
● Arch Pathol Lab Med 2010;134:378
Congenital anomalies
Hirschsprung’s disease
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Originates in colon, but may extend into small bowel, causing enterocolitis and high mortality (see Colon-nontumor chapter)
● Also absence of ganglion cells in small intestine, a rare form of Hirschsprung's disease; found in newborns and associated with increased morbidity and mortality (Gastroenterol Nurs 1999;22:164)
Congenital anomalies
Malrotation
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● From improper embryologic rotation of gut
● Small bowel is found predominantly on right side of abdomen (Wikipedia)
Drawings
=========================================================================
Normal rotation and malrotation
Congenital anomalies
Meckel’s diverticulum
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Most prevalent congenital abnormality of GI tract, in 2% of normal population
● Usually asymptomatic, but also abdominal pain of unknown etiology (Rev Esp Enferm Dig 2011;103:250)
● Due to persistence (failure to involute) of proximal vitelline duct (also called omphalomesenteric duct, connects lumen of fetal intestine to yolk sac)
● Normally, vitelline duct atrophies and becomes fibrous cord connecting umbilicus and bowel, which is subsequently absorbed
● 63% occur in males
● Usually 20 cm proximal to ileocecal valve on antimesenteric side of bowel, 1-8 cm long (Clin Anat 2011;24:416)
● Associated with other congenital anomalies
● Complications: perforation, enteroumbilical fistula, peptic ulceration (usually in adjacent ileum and not in diverticulum), hemorrhage (often massive in children), intussusception, obstruction, carcinoid and other tumors
Case reports
=========================================================================
● 22 year old woman with Crohn’s disease within Meckel's diverticulum (Arch Pathol Lab Med 2003;127:E99)
Treatment
=========================================================================
● Remove if found at surgery, even if incidental
Gross images
=========================================================================
Meckel's diverticulum
Micro description
=========================================================================
● Usually small intestinal mucosa, but 50% have gastric or pancreatic heterotopia
● Contains all 3 layers of bowel wall
Micro images
=========================================================================
With pancreatic heterotopia
Congenital anomalies
Meconium peritonitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Rare prenatal complication in 1 per 30K live births
● GI perforation releases meconium into abdominal cavity, inducing sterile inflammatory reaction and calcium deposition
● Perforation may be due to anoxia leading to bowel ischemia, atresia, congenital bands, Hirschprung’s disease, internal hernia, meconium ileus, stenosis, volvulus or idiopathic
● Presents with fetal distress, maternal polyhydramnios, abdominal distention or a mass
● Newborns with perforation should be evaluated for cystic fibrosis (Pediatr Surg Int 2003;19:75)
Radiology
=========================================================================
● Prenatal ultrasound shows dilated bowel, ascites, polyhydramnios, intra-abdominal calcifications
(Prenat Diagn 2005;25:676)
● Ultrasound findings have prognostic value
(Fetal Diagn Ther 2003;18:255,
Prenat Diagn 2007;27:960)
Case reports
=========================================================================
● 35 week old female with intrauterine distress
(Case of the Week #106)
Treatment
=========================================================================
● Surgical
● Gestational age at diagnosis does not predict postnatal outcome
(J Pediatr Surg 1995;30:979)
Gross description
=========================================================================
● Organized peritonitis with fibrosis, calcifications, dense intestinal adhesions
● Meconium pseudocyst (fibrous wall) may form
Gross images
=========================================================================
Abdominal cavity
Small intestine
Micro description
=========================================================================
● Peritoneal surface shows fibrinous exudate with microcalcifications, bile pigment-like debris, histiocytes, chronic inflammatory cells
Micro images
=========================================================================
Peritoneal surface
Differential diagnosis
=========================================================================
● Vernix caseosa peritonitis: cheesy white exudate coats the visceral organs after cesarean section (J Obstet Gynaecol 2007;27:660)
Congenital anomalies
Omphalocele
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Infant born with herniated abdominal contents into ventral membranous sac because abdominal musculature fails to form
Clinical images
=========================================================================
Ruptured omphalocele
Differential diagnosis
=========================================================================
● Gastroschisis: similar, but umbilical cord is not involved
Additional references
=========================================================================
Patterns of abnormal small bowel architecture
Severe villous abnormality
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Flat intestinal mucosa with no villi seen
● Usually diffuse, with epithelial lymphocytosis, crypt hyperplasia, numerous mitotic figures
● Mucosa actually of normal villous thickness
● Due to celiac sprue, refractory or unclassified sprue, other protein allergies, lymphocytic enterocolitis
Patterns of abnormal small bowel architecture
Variable villus abnormality and crypt hypoplasia
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Villi focally flat or mild/moderate villus shortening
● Also increased intraepithelial lymphocytosis, decreased crypt mitotic figures
Etiology
=========================================================================
● Marasmus: severe protein-calorie malnutrition
● Kwashiorkor: protein malnutrition but adequate caloric intake
● Megaloblastic anemia: vitamin B12 or folate deficiency, no increased inflammatory cells
● Chemoradiation effect: apoptosis, atypical cells
● Microvillus inclusion disease
Patterns of abnormal small bowel architecture
Nonspecific variable villus abnormality
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Various villus abnormalities, usually not flat mucosa
● Usually due to partial treated celiac sprue
Malabsorption
Malabsorption-general
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Standard site for biopsies is proximal jejunum, just distal to ligament of Trietz
● Mount specimen mucosal side up on solid substance, then embed perpendicular to mounting material; then step section or serial section
● Small bowel is important for absorption of fats, fat-soluble vitamins, proteins, carbohydrates, electrolytes, minerals, water
● In US, most common malabsorption disorders are celiac sprue, pancreatic insufficiency and Crohn’s disease
● Steatorrhea: bulky, greasy stools associated with weight loss, anorexia, muscle wasting
Symptoms associated with specific deficiencies
=========================================================================
● Diarrhea, flatus, abdominal pain, weight loss, mucositis, anemia (iron, folate, Vitamins B6, B12)
● Bleeding / purpura (Vitamin K)
● Osteopenia, tetany (calcium, magnesium, vitamin D)
● Amenorrhea / impotence / infertility (generalized malnutrition)
● Hyperparathyroidism (calcium, vitamin D)
● Edema (albumin)
● Dermatitis (zinc, vitamin A, fatty acids, niacin)
● Peripheral neuropathy (vitamins A, B12)
Physiologic classification of malabsorption
=========================================================================
Disturbances related to:
● (a) Intraluminal digestion: saliva, gastric peptic digestion, small bowel, bile salts
● (b) Terminal digestion: hydrolysis of carbohydrates and peptides by disaccharidases and peptidases in brush border of small bowel
● (c) Transepithelial transport: across small bowel epithelium to intestinal vasculature; fatty acids to triglycerides, cholesterol to chylomicrons
(a) Causes of defective intraluminal digestion
● Digestion of fats/proteins: pancreatic insufficiency due to pancreatitis or cystic fibrosis, Zollinger-Ellison syndrome
● Defective bile secretion (fat solubilization): ileal dysfunction or resection with decreased bile salt uptake, cessation of bile flow (obstruction, hepatic dysfunction), nutrient preabsorption or modification by bacterial overgrowth
(b/c) Causes of abnormalities in terminal digestion or transepithelial transport
● Disaccharidase deficiency (lactose intolerance), bacterial overgrowth, abetalipoproteinemia, defects in ileal bile acid transporter
Malabsorption
Abetalipoproteinemia
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Rare; due to mutations in MTP gene encoding microsomal triglyceride transfer protein (MTP); autosomal recessive (Ann Hepatol 2011;10:221)
● Causes defect in synthesis and export of apoprotein B from intestinal mucosal cells
● As a result, free fatty acids and monoglycerides cannot be assembled into chylomicrons and become triglycerides stored within cells, causing lipid vacuolization
● Symptoms: failure to thrive, diarrhea, steatorrhea
Laboratory
=========================================================================
● Lipid profile shows no chylomicrons, no VLDL, no LDL
● CBC smear shows acantholytic red blood cells (Burr cells) due to lipid membrane abnormalities
Micro description
=========================================================================
● Marked fat vacuoles in apical villous cytoplasm, normal villi
Positive stains
=========================================================================
● Fat stains highlight lipid vacuoles
Differential diagnosis
=========================================================================
● Megaloblastic anemia
● Celiac sprue
● Tropical sprue
Malabsorption
Acrodermatitis enteropathica
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Autosomal recessive, linked to zinc deficiency, affects children
● Genetic defect mapped to SLC39A4 gene at 8q24, encodes zinc transporter Zip4 (J Am Acad Dermatol 2007;56:116)
● Cutaneous lesions (perioral and extremity skin lesions, alopecia, nail dystrophy), diarrhea, malabsorption
Treatment
=========================================================================
● Zinc sulfate
Micro description
=========================================================================
● Severe villus abnormality in some; normal in others
Electron microscopy description
=========================================================================
● Rodlike fibrillar inclusions in Paneth cells
Malabsorption
Agammaglobulinemic sprue
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Very rare; no plasma cells in lamina propria
Malabsorption
Celiac sprue
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Major cause of malabsorption - almost all adults in North America with severe villous abnormality and crypt hyperplasia have celiac sprue
● Also called nontropical sprue, gluten-sensitive enteropathy, celiac disease
Pathophysiology
=========================================================================
● Individuals with genetic predisposition have increased immunological responsiveness to prolamins such as dietary wheat gliadin and similar proteins in barley, rye, possibly oats
● Gluten is an alcohol soluble, water insoluble protein component in wheat, oat, barley, rye
● Gluten is mostly made up of 2 groups of proteins: ethanol-soluble gliadins and ethanol-insoluble glutenins
● Gliadin contains chiefly proline and glutamine amino acids
● αGliadin is most toxic to celiac patients
● Gliadin serves as a substrate for transglutaminase (85-kDa enzyme) and becomes cross-linked to it creating a neoantigen – induces immune response
● Disease is due to abnormal cell mediated immunity - gluten exposure causes accumulation of intraepithelial cytotoxic T cells and helper T cells in lamina propria
Clinical features
=========================================================================
● Affects 1 per 200-300 whites in Western countries, onset typically in childhood, rare in Africa, Japan, China
● HLA DQ alpha/beta heterodimer appears to confer susceptibility (90% have DQw2 HLA on #6), linked to HLA B8 (80%)
● Also associated with lymphocytic gastritis / colitis, selective IgA deficiency, type 1 diabetes, Sjogren’s syndrome, autoimmune thyroiditis
● Does not appear to be associated with H. pylori gastritis
(Am J Gastroenterol 2006;101:1880)
Symptoms:
● Newborns: diarrhea and failure to thrive
● Symptoms of episodic diarrhea, flatulence, weight loss, fatigue begin as late as age 40; also abdominal pain and distention, weight loss (Clin Med Res 2004;2:71)
● Clinical and microscopic improvement after dietary changes
Late onset:
● 40’s and 50’s
● Symptoms of short stature, infertility, peripheral neuropathy, iron or folate deficiency, osteoporosis, indigestion, dental enamel defects
Complications:
● Long term risk of malignant disease is 2x normal, usually T cell intestinal lymphomas
● Also GI or breast carcinomas or esophageal squamous cell carcinoma
Seronegative celiac disease
=========================================================================
● Individuals lack serum autoantibodies, have normal villous architecture or mild atrophy
● Increased intraepithelial lymphocytes (IEL)
● Tissue transgultaminase IgA immune deposits are detectable in lamina propria
Classification
=========================================================================
Old Marsh-Oberhuber classification (5 states of small-intestinal mucosal injury (types 0–4)):
● Type 0: Preinfiltrative: normal small-intestinal mucosa with less than 30 IELs per 100 enterocytes
● Type 1: Infiltrative type: normal villous and crypt architecture ( >3 1) and an increased IELs (>30 IELs per 100 enterocytes)
● Type 2: Infiltrative-hyperplastic type: normal villous architecture and crypt hyperplasia with an increased number of IELs-rare
● Type 3: Destructive (flat mucosa) type of CD lesion: 3 different subgroups depending on the degree of villous atrophy
● Type 3a: Mild villous atrophy with villous to crypt ratio of <3 1 or 2 1, and increased IELs
● Type 3b: Marked villous atrophy with villous to crypt ratio of <1 1, and increased IELs
● Type 3c: Total villous atrophy with completely flat mucosa and increased IELs
● Type 4: Atrophic type (hypoplastic); very rare pattern, flat mucosa with only a few crypts and near-normal IEL counts
New classification (Corazza and Villanacci):
● Grade A: Nonatrophic, with normal crypt and villous architecture and increased IELs (>25 IELs per 100 enterocytes)
● Grade B1: Atrophic, with villous to crypt ratio <3 1, but villi are still detectable and IELs are increased (>25 IELs per 100 enterocytes)
● Grade B2: Atrophic and flat, villi are not detectable and increased IELs are noted (>25 IELs per 100 enterocytes)
Comparison of classification systems
Diagnosis
=========================================================================
● Antitransglutaminase, antigliadin or antiendomysial antibodies plus clinical malabsorption plus typical histologic findings plus improvement in symptoms and histology after gluten withdrawal
Laboratory
=========================================================================
● Elevated serum IgA except in those with IgA deficiency (more common in these patients than normals)
● Also IgA anti-transglutaminase, antiendomysial, antireticulin and antigliadin antibodies
Sensitivity of various antibodies
Serum IgA:
● Used to monitor compliance with gluten-free diet
Antitransglutaminase antibody:
● Sensitive marker of disease
IgA anti-endomysial antibody:
● Detect with monkey esophageal tissue
● Sensitive and specific, although also positive in dermatitis herpetiformis
IgA and IgG anti-gliadin antibody:
● Less sensitive than antitransglutaminase and antiendomysial antibodies
Anti-reticulin antibody:
● In 40%, but nonspecific
● Also seen in Crohn's disease, myasthenia gravis, Sjogren’s, other
Case reports
=========================================================================
● 56 year old woman with long history of untreated celiac sprue
(Case of the Week #127)
Treatment
=========================================================================
● Improves clinically and microscopically after dietary withdrawal of wheat gliadins and related grain proteins
Gross description
=========================================================================
● Usually flat, scalloped mucosa
● May be normal
Micro description
=========================================================================
● Note: diagnosis requires clinical correlation - pathology report can only state "consistent with celiac sprue"
● Increase in intraepithelial lymphocytes, most sensitive marker is 40+ lymphocytes per 100 surface or upper crypt enterocytes
● Early-clustering of 12+ lymphocytes at tip of villi and extending evenly down the sides of the villus (Mod Pathol 2003;16:342)
● Diffuse enteritis with marked atrophy or total loss of villi
● Fat globules in surface epithelium, enterocytes have stratified nuclei, lose their brush border, increased crypt mitotic figures
● Crypts are elongated and hyperplastic, but overall mucosal thickness is the same
● Also increase in plasma cells in lamina propria
● Changes more marked in proximal small bowel (greater exposure) and abnormalities recede last here after gluten withdrawal
● Significant duodenal neutrophilia often noted in children, associated with more active disease
● Disease activity is proportional to eosinophilic infiltration and foveolar metaplasia (Am J Surg Pathol 2012;36:1339)
● Do not overdiagnose on biopsy based on minimal and nonspecific histologic changes, as diagnosis has lifelong implications (Arch Pathol Lab Med 2008;132:1594)
Micro images
=========================================================================
Marsh-Oberhuber classification
Marsh Type I & III lesions
Various images
Case of the Week #127
Virtual slides
=========================================================================
Small intestine
Differential diagnosis
=========================================================================
● Autoimmune enteropathy: crypt injury or destruction, anti-enterocyte antibodies, typically in first 6 months of life
● Common variable immunodeficiency: no plasma cells, marked lymphoid hyperplasia, often Giardia infection
● Crohn’s disease
● Dermatitis herpetiformis: associated with gluten-sensitive enteropathy but also has skin lesions
● Duodenal intraepithelial lymphocytosis with normal villous architecture: associated with H. pylori infection, but no other features of celiac disease (Mod Pathol 2005;18:1134)
● Infectious enteritis: prominent neutrophils, normal intraepithelial lymphocytes
● Kwashiorkor
● Morbid obesity: intraepithelial lymphocytosis in architecturally normal small intestinal mucosa (Arch Pathol Lab Med 2007;131:344)
● Other protein allergies: sprue symptoms disappear and reappear if offending substance is withdrawn / reintroduced
● Tropical sprue, severe: no antiendomysial antibodies, responds to antibiotics and folate
Differential diagnosis of intraepitheliial lymphocytes
=========================================================================
● H.Pylori associated gastroenteritis, nongluten food hypersensitivity, infections (giardia, cryptosproridia), bacterial overgrowth, drugs (NSAID’s), IgA deficiency, common variable immunodeficiency, Crohn’s disease, small bowel allograft rejection (Arch Pathol Lab Med 2010;134:826)
Table
Additional references
=========================================================================
● J Clin Pathol 2005;58:573,
Arch Pathol Lab Med 2012;136:735
Malabsorption
Collagenous sprue
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 13 November 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Subtype of refractory sprue with patchy, excessive subepithelial collagen deposits (5 of 10 patients in one study, Am J Surg Pathol 2000;24:676)
● May eventually respond to gluten-free diet (Mod Pathol 2010;23:12), but disease may also be fatal
Micro description
=========================================================================
● Small intestinal villous and crypt atrophy, subepithelial collagen deposit thicker than 12 µm that entraps lamina propria cellular elements (Arch Pathol Lab Med 2011;135:803)
Micro images
=========================================================================
Various images
Malabsorption
Dermatitis herpetiformis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
See also Skin-nontumor chapter
General
=========================================================================
● Usually present with skin manifestations only and are not aware of the underlying small-bowel problems
● Resembles celiac sprue - both respond to gluten free diet (skin lesions improve), both associated with HLA-B8 and HLA-DR3, both associated with lymphoma
● Pruritic, papulovesicular lesions symmetrically distributed on scalp, buttocks, extremities, with granular deposition of IgG at epidermal-dermal junctional
● Diagnosis: circulating IgA antibodies against epidermal transglutaminase (eTG) and tissue transglutaminase (tTG) (J Invest Dermatol 2008;128:332, J Am Acad Dermatol 2009;61:39)
Micro description
=========================================================================
● Severe mucosal lesion on small bowel biopsy
● May be patchy with variable villus abnormality
Malabsorption
Disaccharidase (lactase) deficiency
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Disaccharidases are located in apical cell membrane of villous absorptive epithelial cells
Congenital deficiency:
● Rare; malabsorption evident with milk feeding, which causes explosive, watery, frothy stools and abdominal distention
Acquired deficiency:
● Common in North American blacks
● Causes osmotic diarrhea
● Acquired deficiency of lactase also occurs in duodenal mucosa of children with celiac disease (J Gastroenterol Hepatol 2008;23:348)
Diagnosis
=========================================================================
● Increased hydrogen in breath test due to bacterial fermentation of undigested lactose
Treatment
=========================================================================
● Dietary elimination of milk and milk products
Malabsorption
Lymphangiectasia
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 22 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Primary intestinal lymphangiectasia is rare disorder of dilated intestinal lacteals resulting in lymph leakage into the small bowel lumen, causing protein-losing enteropathy leading to lymphopenia, hypoalbuminemia and hypogammaglobulinemia (Orphanet J Rare Dis 2008;3:5, eMedicine)
● Dilation of lymphatics in mucosa, submucosa or subserosa
● Primary: children, due to congenital obstructive defective in lymphatics
● Secondary: due to constrictive pericarditis, Crohn’s (Virchows Arch 2008;452:57), intestinal malignancy, myocardial disease, pancreatitis, retroperitoneal fibrosis, sarcoidosis, Waldenström macroglobulinemia
Treatment
=========================================================================
● Resection, treatment of underlying conditions
Clinical images
=========================================================================
Markedly dilated lymphatics
Micro images
=========================================================================
Markedly dilated lymphatics
Malabsorption
Microvillus inclusion disease
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Also called congenital or familial microvillous atrophy
● Disorder of intestinal brush border that causes intractable watery diarrhea with steatorrhea in infants
● Patients require total parental nutrition, and rarely live beyond age 2 years
● Villous atrophy may be due to apoptotic cell loss
(Hum Pathol 2000;31:1404)
Treatment
=========================================================================
● Small bowel transplant
Micro description
=========================================================================
● Severe villous abnormality with crypt hypoplasia, resembling celiac sprue but without lymphocytosis
● Increased enterocyte apoptosis and proliferation, bubbly vacuolated apical cytoplasm with extensive or patchy absence of brush border, absence of inflammation
(Ultrastruct Pathol 2010;34:327)
Micro images
=========================================================================
Various images
Positive stains
=========================================================================
● CD10 (Am J Surg Pathol 2002;26:902), PAS, polyclonal CEA, alkaline phosphatase (cytoplasmic staining vs. linear brush border staining in normals)
● Vacuoles - PAS, CEA
● Cytoplasmic CD10 staining of absorptive colonocytes can aid in the diagnosis in situations where only colonic biopsy could be obtained
(Am J Surg Pathol 2010;34:970)
Electron microscopy description
=========================================================================
● Abnormal microvillus structures at luminal border of enterocytes
● Apical intracytoplasmic inclusions lined by microvilli
Electron microscopy images
=========================================================================
Neonatal congenital microvillus atrophy
Malabsorption
Refractory sprue
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Also called unclassified sprue
● Celiac sprue that does not respond to gluten free diet of 6-12 months (note: wheat is present in many foods, so must verify that diet is actually gluten free), and is not due to other disorders
● Must rule out gluten contamination, microscopic colitis, bacterial overgrowth, pancreatic insufficiency, lactose intolerance, inflammatory bowel disease, lymphoma (Gut 2010;59:547)
Clinical features
=========================================================================
● Two subtypes: Type 1 (normal intraepithelial lymphocyte phenotype) and type 2 (presence of abnormal clonal intraepithelial lymphocyte phenotype)
● Often associated with thromboembolic events, coexisting autoimmune disorders, cavitation of mesenteric lymph nodes and hyposplenism, lymphoma
Table
Micro images
=========================================================================
Various images
Malabsorption
Tropical sprue
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 14 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Also called post-infectious sprue
● Affects people living in or visiting the tropics, particularly Caribbean (not Jamaica), Africa, India, SE Asia, Central/South America (Case Rep Gastroenterol 2010;4:168)
● Has endemic and epidemic features
● May be due to E. coli or Haemophilus
● Symptoms: malabsorption within weeks of acute diarrheal enteric infection
Treatment
=========================================================================
● Broad-spectrum antibiotics (tetracycline), folic acid, vitamin B12
● No increased risk of intestinal lymphoma
Micro description
=========================================================================
● Variable villous atrophy (none, partial, total)
● Injury to entire small bowel (not proximal as in celiac sprue), inflammatory infiltrate, crypt hyperplasia
Micro images
=========================================================================
Various images
40 yr old man with chronic diarrhea who improved after antibiotics; marked villous atrophy in duodenal biopsy but no increase in intraepithelial lymphocytes (courtesy of Dr. Hanni Gulwani)
Additional references
=========================================================================
●
Gastrointest Endosc 2007;66:377,
Dig Dis Sci 2011;56:161
Ulcers
Duodenal peptic ulcer
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Decreasing incidence, but still common (Int J Clin Exp Pathol 2012;5:46)
● Imbalance between gastric acid production and protective factors of intact epithelium and bicarbonate production
● Increased gastric acid production requires intact fundic mucosa
● Associated with duodenal Helicobacter pylori and gastric metaplasia
● Not associated with malignancy
Treatment
=========================================================================
● H2 blockers
● 80% heal within a month
● Surgery if hemorrhage, perforation, obstruction or failure to respond to medical treatment
● Ulcers located posteriorly bleed easily due to pancreaticoduodenal and gastroduodenal arteries in the vicinity
Gross description
=========================================================================
● Usually single lesion within 2 cm of pylorus
● Multiple lesions throughout duodenum suggest Zollinger-Ellison syndrome
● Margins well defined
● No heaped up edges
● May have large vessel with open lumen at ulcer base
● Also fibrosis and shortening of duodenum
Micro description
=========================================================================
● Ulcer usually < 1 cm, circular, small
● Brown ulcer base (digested blood), no induration of margins of ulcer
● Abrupt lesions with normal adjacent mucosa
● No scarring or blood vessel thickening
● Gastric foveolar cell metaplasia and chronic duodenitis common
● Various villus abnormalities in proximal duodenum with active duodenitis
● Also Brunner’s gland hyperplasia
● Helicobacter pylori often present
Micro images
=========================================================================
Various images
Additional references
=========================================================================
●
World J Gastroenterol 2010;16:5496
Ulcers
Marginal ulcer
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Most common abnormality found among symptomatic patients after gastric bypass surgery on flexible upper endoscopy examination
● Usually in jejunum distal to stoma
Clinical images
=========================================================================
Various images
Ulcers
Small bowel ulcer
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Nonspecific small bowel ulcers are rare diagnoses of exclusion (BMC Gastroenterol 2011 May 10;11:51)
● Almost always related to other gastroduodenal disease, including celiac disease, congenital anomalies, drugs (NSAID, Korean J Gastroenterol 2008;52:134), endometriosis, enteric-coated potassium and hydrochlorothiazide, mechanical disorders, radiation, specific inflammations, tumors, vascular occlusion
● Cause obstruction, perforation, hemorrhage
Clinical images
=========================================================================
Endoscopic image
Gross description
=========================================================================
● Ulcer with adjacent hemorrhage, congestion, edema
Micro description
=========================================================================
● Nonspecific changes
Micro images
=========================================================================
Various images
Inflammatory disorders
Autoimmune enteropathy
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Severe and intractable watery diarrhea syndrome in infants associated with antibodies to intestinal epithelial cells
● Includes IPEX syndrome, an X linked recessive disorder due to mutations in FOXP3 gene (Mod Pathol 2009;22:95)
● Usually requires total parenteral nutrition
● Similar condition in adults associated with variable immunodeficiency and type I diabetes, rheumatoid arthritis, hemolytic anemia
Treatment
=========================================================================
● Immunosuppressive agents
Micro description
=========================================================================
● Variable villus abnormality, few intraepithelial lymphocytes
● May have colitis, increased expression of MHC class II antigens
Micro images
=========================================================================
IPEX syndrome
Inflammatory disorders
Behcet’s disease
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Rare immune-mediated systemic vasculitis that often presents with mucous membrane ulceration and ocular problems (Wikipedia)
● GI involvement in 10% of cases, usually ileum and cecum
● Punched out ulcers that may perforate
● Perivascular inflammation, necrotizing and nonnecrotising lymphocytic vasculitis affecting small veins and venules is often present
● Also aphthous stomatitis, genital ulcers, relapsing iritis
Case reports
=========================================================================
● 30 year old man with massive GI bleeding (Korean J Gastroenterol 2007;49:400)
Gross images
=========================================================================
Various images
Micro images
=========================================================================
Ulcers-site unspecified
Inflammatory disorders
Collagenous enterocolitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● May be associated with collagenous colitis, collagenous gastritis or collagenous sprue
● High intraepithelial lymphocyte count in terminal ileum biopsies of affected patients
(Mod Pathol 2003;16:115,
Am J Surg Pathol 2002;26:1484, Am J Surg Pathol 2011;35:1151)
● Lymphocytes are mostly suppressor T cells
● Symptoms: chronic nonbloody diarrhea, relatively normal endoscopy
Micro description
=========================================================================
● Subepithelial collagen deposition in terminal ileum, partial villous atrophy
Micro images
=========================================================================
Terminal ileum with increase in subepithelial collagen
Positive stains
=========================================================================
● Trichrome highlights collagen
Inflammatory disorders
Crohn’s disease
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Relapsing, discontinuous, transmural granulomatous disease from oral cavity to anus, usually involves small intestine and colon (eMedicine)
● Also called terminal ileitis, regional enteritis, granulomatous colitis
Epidemiology
=========================================================================
● Affects primarily Western populations, equal gender incidence
● 3 per 100,000, peaks in teens/twenties and 50/60’s
● RR: Whites 2-5:1, Jews 3:1
● Associated with smoking
● Monozygotic twins have 30-50% concordance
Sites
=========================================================================
● Small bowel only (particularly terminal ileum) in 40%, colon only in 30%
● Rarely other sites in GI tract
Etiology
=========================================================================
● Cause unknown, although Yersinia DNA in 30% of cases by PCR (Am J Surg Pathol 2003;27:220)
● May be due to alteration in steady state between immune system activation by microbes, antigens, endogenous inflammatory stimuli and host defenses that maintain integrity of mucosa and down-regulate inflammation
● Unclear if mucosal pathology is primary or secondary (Inflamm Bowel Dis 2010;16:896)
Clinical features
=========================================================================
Symptoms:
● Variable, including episodic mild diarrhea, fever, pain
● May be precipitated by stress
● If colon affected, may have anemia
● 20% have abrupt onset, resembling acute appendicitis or bowel perforation
Extraintestinal symptoms:
● Migratory polyarthritis, sacroiliitis, ankylosing spondylitis, erythema nodosum, clubbing of fingertips, primary sclerosing cholangitis (not as common as with ulcerative colitis)
● Occasionally uveitis, pericholangitis, renal disorders secondary to periureteral fibrosis
Complications:
● Fibrosing strictures (common in terminal ileum), fistulas to loops of bowel, bladder, vagina, perianal skin
● Also protein losing enteropathy, generalized malabsorption, vitamin B12 deficiency, bile salt malabsorption with steatorrhea, perforation, abscesses
● 5x risk for GI carcinoma, usually adenocarcinoma of ileum
Course:
● Progressive
● Only rarely regresses
Crohn's related carcinoma
=========================================================================
Small bowel:
● Mean 20 years after onset of Crohn’s, usually ileum or site of active disease
● Often in strictures, 25% in bypassed bowel loops
● Poorly differentiated, poor prognosis
● Dysplasia in adjacent epithelium
Colon:
● Mean 20 years after diagnosis, usually gross intraluminal lesion, 20% in bypassed rectum
● Better differentiated and better prognosis than small bowel carcinomas
● Dysplasia near and distant from tumor
Treatment
=========================================================================
● Medical (immunosuppressive therapy), surgical
Clinical images
=========================================================================
Endoscopy
Gross description
=========================================================================
● Serosa dull and granular with creeping fat (mesenteric fat wraps around bowel surface), thick/rubbery intestinal wall (due to edema, inflammation, fibrosis, hypertrophy of muscularis propria), narrow lumen (string sign on barium enema), sharp demarcation of affected from uninvolved bowel, fistulas
● No rectal involvement
● Early - aphthous mucosal ulcers that coalesce into long, serpentine linear ulcers along bowel axis with cobblestone appearance
● Late - shortened and fibrotic mesentery; prominent reactive lymph nodes
Clinical images
=========================================================================
Terminal ileum: mucosal pseudopolyps (inflammatory pseudopolyps)
Terminal ileum: cobblestone change
Thickened bowel wall and fat wrapping
Micro description
=========================================================================
● Sharply delimited and typically transmural involvement of bowel by an inflammatory process with mucosal damage, noncaseating, non-confluent, sarcoid-like granulomas (60%) in involved and non-involved bowel, fissuring (30%) deep into muscularis propria with formation of fistulas and strictures
● Focal neutrophils in epithelium early on, particularly overlying lymphoid aggregates
● Also plasmacytosis, cryptitis, crypt abscesses
● Superficial or deep ulceration, edema, lymphatic dilation, hyperplasia / duplication of muscularis mucosa
● May have prominent nerve plexuses (submucosal, myenteric), fibrosis, muscularization (Histopathology 2012;60:1034)
● Often serositis and thickened bowel wall
● Late - architectural distortion (villus blunting), crypt atrophy, particularly in colon, pyloric or Paneth cell metaplasia in distal colon, rarely cystically dilated glands (enteritis cystica profunda)
● Areas of stricture may have thick and continuous muscle layer from mucosal base to muscularis propria 1 cm or more in length, called “obliterative muscularization of submucosa" (Arch Pathol Lab Med 2001;125:1331)
● Isolated colonic Crohn’s may mimic ulcerative colitis – involve younger patients, only mucosal involvement and with fewer major microscopic features (Mod Pathol 2012;25;295)
Micro images
=========================================================================
Deep fissuring ulcers
Crypt abscess
Obliterative muscularization
Granulomatous enteritis
Lymphoid follicles
Comparison with ulcerative colitis
Virtual slides
=========================================================================
Small intestine
Differential diagnosis
=========================================================================
● Ischemic bowel disease
● Tuberculosis
Inflammatory disorders
Diaphragm disease
Reviewer: Nat Pernick, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Small bowel pathology related to NSAID use, first described in 1988 (J Clin Pathol 1988;41:516)
Treatment
=========================================================================
● Cessation of NSAID use
● Often surgery (Colorectal Dis 2012;14:804) or endoscopic balloon dilation (Gastrointest Endosc 2006;64:1014)
Case reports
=========================================================================
● 46 year old woman with chronic aspirin use (Case of the Week #240)
Gross description
=========================================================================
● Segmentation of ileum by incomplete mucosal diaphragms, defined as thin circumferential membranes resembling the plica circularis, composed of mucosa and submucosa with accompanying fibrosis
● Also ulceration, strictures, perforation
Gross images
=========================================================================
Various images
Micro description
=========================================================================
● Thin circumferential membranes resembling plica circularis, composed of mucosa and submucosa with accompanying fibrosis
● Neuromuscular and vascular hamartoma-like changes, eosinophilic enteritis and acute inflammation (Am J Clin Pathol 2008;130:518).
Micro images
=========================================================================
Top row: H&E; bottom row: trichrome
Differential diagnosis
=========================================================================
● Cryptogenic multifocal ulcerous stenosing enteritis (CMUSE): small intestinal strictures and ulcerations of unknown origin (World J Gastroenterol 2011;17:2873), characterized as atypical vasculitis presenting with unexplained stricture and ulceration of the small bowel in young and middle-aged patients, but without systemic inflammation; treated with steroids
Inflammatory disorders
Duodenitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Inflammation of duodenum due to various causes, associated with dyspepsia
Micro description
=========================================================================
● Increased plasma cells, edema, intraepithelial neutrophils
● Severe cases have villous atrophy, more neutrophils but fewer plasma cells
● Gastric metaplasia, Helicobacter pylori may be present
Micro images
=========================================================================
Various images
Inflammatory disorders
Enterocolic (lymphocytic) phlebitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
Clinical features
=========================================================================
● Venous lesions with lymphocytic infiltration of venular wall, necrotizing phelibitis, granulomatous phlebitis and endothelial and myointimal hyperplasia (Am J Surg Pathol 2000;24:824,
Arch Pathol Med Lab 2007;131:1130)
● Also called lymphocytic or granulomatous or necrotizing phlebitis, myointimal venous hyperplasia
● Also ischemia and necrosis of ileum or colon due to localized phlebitis associated with fresh or organized thrombus of intramural mesenteric veins
● No systemic vasculitis
● Associated with hydroxyethyl rutozide, also other drugs
● Does not recur after surgery
Diagnosis
=========================================================================
● Predominantly lymphocytic infiltration of intramural tributaries of mesenteric veins
Case reports
=========================================================================
● 53 year old man with coexisting lymphocytic colitis, lymphocytic enteritis, and lymphocytic appendicitis (Am J Surg Pathol 2004;28:542)
● 66 year old woman with isolated mesocolic vasculitis (Am J Surg Pathol 2001;25:827)
● 68 year old man with chronic antral ulcer associated with gastroduodenal lymphocytic phlebitis (Am J Surg Pathol 2004;28:1659)
● 74 year old woman with ischemic colitis (Mod Pathol 2000;13:897)
Micro description
=========================================================================
● Lymphocytic infiltrate of venules
Micro images
=========================================================================
Inflammatory disorders
Eosinophilic enteritis / gastroenteritis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Rare disease that may present as obstruction, associated with peripheral eosinophilia and allergic symptoms in children or young adults (Rev Esp Enferm Dig 2004;96:279, Ann Acad Med Singapore 2011;40:379, Ital J Pediatr 2011;37:18)
● Nausea, vomiting, diarrhea, steatorrhea, protein-losing enteropathy
● Symptoms are related to site of infiltration: mucosa of stomach/small bowel-diarrhea and malabsorption; submucosa and muscularis propria-obstruction; subserosa-ascites
Micro description
=========================================================================
● Marked eosinophilic infiltration of bowel wall (>20 eosinophils/HPF in at least one focus), prominent vessels, occasionally necrotizing granulomas and vasculitis
● Eosinophils typically not associated with other inflammatory cells
● Infiltration may be patchy
Micro images
=========================================================================
Various images
Differential diagnosis
=========================================================================
● Ancylostoma caninum infection
● Collagen vascular disease
● Inflammatory bowel disease
● Lymphoma
● Sarcocystis infection
Inflammatory disorders
Graft versus host disease
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Apoptotic cells and fibrosis commonly associated with allogeneic bone marrow transplant (Dig Dis Sci 2012;57:720)
● Recommended to delay biopsies until week 4 of immunosuppressive therapy or later
● Symptoms include severe watery diarrhea, changes in skin and liver
Case reports
=========================================================================
● 22 month old girl with AML and small bowel obstruction post bone marrow transplant (Korean J Hematol 2012;47:142)
Gross images
=========================================================================
Severe chronic GVHD involving small intestine, leading to obstruction of terminal ileum
Micro description
=========================================================================
● Acute: epithelial crypt apoptosis with minimal inflammation; severe cases have sloughing of mucosa
● Chronic: lamina propria fibrosis and submucosal fibrosis extending up to serosa
Micro images
=========================================================================
Severe loss of mucosal epithelium, many basal single cell apoptotic bodies, crypt dropout, submucosal/subserosal fibrosis
Inflammatory disorders
Ileal pouch / pouchitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Pouch is formed from connecting loops of terminal ileum for patients requiring total colectomy; used to create continence in an ileostomy or to preserve anal sphincter function
● Pouches are contraindicated in Crohn’s disease, because they are associated with fistulas and abscess
● Complications: fistula, obstruction, incontinence, leaks, pouchitis
Pouchitis
=========================================================================
● Incidence 8% to 46%
● Some cases are due to initially undiagnosed Crohn’s disease
● Nausea, vomiting, malaise, fever, cramping
● Increased ileal stool that is bloody, watery, foul smelling
● Often with altered bacteria
Treatment
=========================================================================
● Antibiotics, pouch excision
Micro description
=========================================================================
● Decreased epithelial cell mucin, few/no lymphoid follicles
● Ulcers with granulation tissue, cryptitis, crypt abscesses and patchy neutrophils
● Rarely dysplasia
● CD10 staining confirms biopsy site - terminal ileum (CD10+) versus colon (CD10-), although negative staining also occurs in active enteritis (Mod Pathol 2011;24:1627)
Micro images
=========================================================================
CMV pouchitis: biopsy of post-colectomy pouch in 38 year old man with ulcerative colitis (courtesy of Dr. Hanni Gulwani)
CD10 staining
Inflammatory disorders
Jejunitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Also called acute phlegmonous jejunitis
● Rare, men and women age 55+ years
Case reports
=========================================================================
● 61 year old man with phlegmonous jejunitis associated with relatively mild strep infection (Scand J Infect Dis 2000;32:421)
Gross description
=========================================================================
● Sharply demarcated bowel mucosal inflammation, often with serosal pus
● Edematous bowel wall, glassy mesentery, enlarged lymph nodes
Micro description
=========================================================================
● Lymphangitis, regional lymphadenitis, abscesses within mesentery
Micro images
=========================================================================
Various images
Inflammatory disorders
Lymphocytic enterocolitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Refractory spruelike condition associated with colonic mucosal abnormalities (Can J Gastroenterol 2008;22:771)
Micro images
=========================================================================
Lymphocytic ileitis,: ileal biopsy from 28 year old man with chronic diarrhea shows marked increase in intraepithelial lymphocytes (Courtesy of Dr. Hanni Gulwani)
Lymphocytic colitis related
General
=========================================================================
● High intraepithelial lymphocyte count in terminal ileum biopsies (Mod Pathol 2003;16:115, Am J Surg Pathol 2002;26:1484)
● Normal range of ileal lymphocytes is 0-9 lymphocytes / 100 enterocytes, decreases with age (Am J Clin Pathol 2007;127:816)
● Lymphocytes are mostly suppressor T cells
● Symptoms: chronic nonbloody diarrhea, relatively normal endoscopy
Micro images
=========================================================================
Terminal ileum with villous atrophy and increase in intraepithelial lymphocytes
Inflammatory disorders
Malakoplakia
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Rare in small bowel; most likely secondary to bacterial infection (Gastroenterol Clin Biol 2003;27:655, Arch Pathol Lab Med 2010;134:378)
Case reports
=========================================================================
● 70 year old woman with Crohn's disease (Internet Journal of Gastroenterology 2007;5(2))
Micro description
=========================================================================
● Histiocytes contain calcospherites (Michaelis-Gutmann bodies)
Micro images
=========================================================================
Multiple von Hansemann cells and Michaelis-Gutmann bodies in ileum (PAS stain)
Michaelis-Gutmann bodies are calcium+ (von Kossa stain)
Inflammatory disorders
Necrotizing enterocolitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 20 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Acute, necrotizing inflammation of small bowel and colon in patients with myelosuppression
● Also called typhlitis, neutropenic enterocolitis, ileocecal syndrome
● Most common acquired GI emergency of neonates (eMedicine)
● Common in premature or low birth weight infants, particularly when they start on oral foods at 2-4 days
● Also adults with various myeloproliferative disorders, solid malignancies, post-transplant immunosuppression (eMedicine)
● Affects terminal ileum, ascending colon
Etiology
=========================================================================
● Intestinal bacteria invade immature intestinal epithelium, causing subsequent inflammation and tissue necrosis
● Bacteria in food produce more cytokines and injure mucosa
● May be due to TNF receptor 1 dependent depletion of mucus which occurs in immature small intestine (Am J Physiol Gastrointest Liver Physiol 2011;301:G656)
● May also be due to deranged intestinal blood flow (J Pediatr Surg 2011;46:1023)
Drawing
Clinical features
=========================================================================
● Symptoms: mild GI disturbance or fulminant illness with intestinal gangrene, perforation, sepsis, shock
● Complications: short bowel syndrome, malabsorption (due to ileal resection), strictures, recurrence
Treatment
=========================================================================
● Fluids and surgery if gangrene/perforation
Gross images
=========================================================================
Various images
Micro description
=========================================================================
● Early: mucosal edema, hemorrhage, necrosis
● Late: hemorrhagic and gangrenous bowel wall, fibrous strictures;often pneumatosis cystoides intestinalis
● After recovery, Paneth cell hyperplasia; colon also shows metaplastic Paneth cells (Pediatr Res 2011;69:217)
Micro images
=========================================================================
Various images
Additional references
=========================================================================
● Pediatr Res 2011;69:183,
J Pediatr Gastroenterol Nutr 2011;52:140
Inflammatory disorders
Radiation enterocolitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Observed acutely or years after radiation therapy for cervical carcinoma, Wilm’s tumor, lymphoma or other peritoneal tumors
Clinical features
=========================================================================
● Acute: anorexia, cramps, diarrhea due to mucosal injury and malabsorption
● Chronic: may present as inflammatory colitis or indolent; also vascular injury, ischemic fibrosis, stricture
● Treatment: resection if severe
Gross description
=========================================================================
● Thickened bowel wall
Micro description
=========================================================================
Acute:
● Varies from mild epithelial damage to massive necrosis and ulceration (BMC Surg 2004;4:10)
● Loss of columnar shape and nuclear polarity of enterocytes, nuclear pyknosis, bizarre nuclei, mucin depletion and decreased mitoses
● Also fibroblasts and endothelium with submucosal edema but low nuclear to cytoplasmic ratio, preservation of architecture
● No desmoplasia, no infiltrative pattern
Chronic:
● Atrophic and ulcerated mucosa, ectatic blood vessels, fibrosis of submucosa and muscular wall, vascular wall thickening, vascular stenosis
● Possible fistula formation, atherosclerosis-like changes of vasculature (subintimal lipid-laden macrophages, calcification, thrombosis), hyalinization of lamina propria
Micro images
=========================================================================
Acute changes (mice)
Inflammatory disorders
Sarcoidosis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 15 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Multisystemic disorder of unknown cause characterized by noncaseating granulomas in involved organs (Orphanet J Rare Dis 2007 Nov 19;2:46); usually does NOT involve the small bowel (QJM 2010;103:60)
● Must rule out Crohn’s disease before making this diagnosis
● Presents with malabsorption, protein losing enteropathy and lymphangiectasia secondary to lymphatic obstruction
Case reports
=========================================================================
● 36 year old woman with 10 kg weight loss (Rev Med Interne 2010;31:262)
Clinical images
=========================================================================
Gastrocopy shows duodenal granulomatous involvement
Micro description
=========================================================================
● Compact bland noncaseating granulomas that involve bowel wall and regional nodes
● Must rule out Crohn's disease
● Negative stains / PCR for fungi, AFB
Micro images
=========================================================================
Various images
Inflammatory disorders
Ulcerative colitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 16 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Severe UC is associated with contiguous backwash ileitis and appendix involvement
● UC also associated with postcolectomy pouchitis
● Rarely diffuse duodenitis is associated with ulcerative colitis, but it does not behave as Crohn’s disease (Am J Surg Pathol 2000;24:1407)
● Diffuse chronic duodenitis in ulcerative colitis patients who have colectomy is a strong predictor of pouchitis (Am J Surg Pathol 2010;34:1672)
Backwash ileitis
=========================================================================
● Recommended to restrict use of term to active enteritis involving ileum contiguously from cecum that has a similar or greater degree of active inflammation; mild cases predominantly involves the superficial mucosa in a contiguous pattern
● Focal isolated ileal erosions, mucous gland metaplasia, or patchy edema with mild active inflammation are features of Crohn's disease (Am J Clin Pathol 2006;126:365)
Micro images
=========================================================================
Mild backwash ileitis in moderately active cecal chronic ulcerative colitis resection specimen; mucosa of distal ileum is edematous, and villi are slightly wider and flatter than norma; most of the active colitis stops abruptly at transition point between the 2 mucosae; the two most distal villi have the greatest degree of injury, including blunting, edema, and neutrophils in the lamina propria and surface epithelium
Moderate (left) and severe (center, right) backwash ileitis
Terminal ileum inflammation: (A) grade 1, cryptitis; (B) grade 2, scattered crypt abscesses
(C) grade 3, numerous crypt abscesses; (D) grade 4, ulcer
Infectious disorders
Diarrhea and dysentery
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 16 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Usual fluid input into intestines is 9 liters/day (oral intake-2, saliva-1, gastric-2, pancreatic-2, intestinal-1, other-1)
● Most reabsorbed in small bowel and colon
● Diarrhea: increase in stool mass, frequency or stool fluidity (3 or more loose stools/day, eMedicine)
● Dysentery: low volume, painful, bloody diarrhea
● Exudative disease: purulent bloody stools, persists with fasting: due to bacteria (Salmonella, Shigella, Campylobacter), Entamoeba histolytica, idiopathic inflammatory bowel disease, typhlitis
● Malabsorption: bulky stools, abates with fasting, due to defective intraluminal digestion, primary mucosal cell abnormalities, reduced small bowel surface area, lymphatic obstruction, Giardia lamblia
Secretory diarrhea:
● >500 ml of fluid stool per day, isotonic with plasma, persists during fasting
● Infectious (viral damage to epithelium): rotavirus, Norwalk virus, enteric adenoviruses, calicivirus, astrovirus
● Infectious (enterotoxin): Vibrio cholera, E. coli, Bacillus cereus, Clostridium perfringens
● Neoplastic: tumor production of peptides, villous adenoma in distal colon
● Excessive laxatives
Osmotic diarrhea:
● Due to luminal solutes, abates with fasting, stool osmolality > electrolyte concentration by 50 mOsm
● Associated with lactase deficiency, lactulose therapy, gut lavage, antacids, primary bile acid malabsorption
Deranged motility:
● Improper gut neuromuscular function causes decreased transit time
● Due to surgical resection of gut, irritable bowel syndrome (neural dysfunction), hyperthyroidism, diabetic neuropathy, carcinoid syndrome
● Decreased motility due to small bowel diverticula, blind loop, bacterial overgrowth
Epidemiology
=========================================================================
● 12,000 deaths/year from dehydration in developing countries - 50% of all deaths before age 5
● Affects 40% of US population - #2 in attack rates in US after common cold
Micro description
=========================================================================
● Patchy lesions with variable villus abnormality, rarely severe
● Increased chronic and acute inflammatory infiltrate in epithelium and lamina propria
● Small intestinal bacterial overgrowth: common cause of chronic diarrhea and malabsorption with either villous blunting or normal duodenal biopsy (Arch Pathol Lab Med 2010;134:264)
Micro images
=========================================================================
Small intestinal bacterial overgrowth
Infectious disorders
Bacterial enterocolitis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 16 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Bacterial related disease due to either ingestion of pre-formed toxin (Staphylococcus aureus, Vibrio cholera, Clostridium perfringens), infection by toxigenic organisms or infection by enteroinvasive organisms which invade and destroy mucosal epithelium cells (eMedicine)
● Bacterial adhere to mucosal epithelial cells, elaborate enterotoxins, have capacity to invade
● Adhere by plasmid-mediated adhesins (E. coli, V. cholera), fimbriae or pili
● Adhesion destroys microvilli brush border
Clinical features
=========================================================================
● Complications due to massive fluid loss and loss of mucosal barrier include dehydration, sepsis, perforation
● Salmonella: invades via transcytosis with minimal epithelial damage
● Yersinia enterocolitica: penetrates ileal mucosa, multiplies in Peyer’s patches and regional lymph nodes
● Insidious infection: Yersinia and Mycobacterium tuberculosis
● Cytotoxins: Shiga toxin, enterohemorrhagic E. coli
Enterotoxins:
● Bind to cell membrane, enter cell, activates massive electrolyte secretion (cholera toxin, E. coli heat-labile and heat-stable toxins produce travelers diarrhea)
● No white blood cells in stool
Bacterial invasion:
● Enteroinvasive E coli and Shigella have plasmid that mediates epithelial cell invasion via microbe-simulated endocytosis; then intracellular proliferation, cell lysis, cell to cell spread
Patients ingest preformed toxins:
● Symptoms within hours
● Explosive diarrhea and acute abdominal distress
● 1-2 days
● C. botulinum may produce rapid, fatal respiratory failure
Infection with enteric pathogens:
● Incubation of hours-days
● Diarrhea and dehydration (secretory enterotoxin) or dysentery (cytotoxin or enteroinvasive)
Travelers diarrhea:
● Fecally contaminated water/food
● Begins abruptly, subsides in 2-3 days
Micro description
=========================================================================
● Decreased epithelial cell maturation, increased mitotic figures, hyperemia and edema of lamina propria, variable neutrophils, modest villus blunting of small bowel
● Late - lymphocytes, plasma cells, regenerative change
Differential diagnosis
=========================================================================
Infectious disorders
AIDS / HIV
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 16 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Small bowel infections are associated with Kaposi’s sarcoma, lymphoma, smooth muscle tumors, other infectious disorders (must look for them / rule them out)
● 30-60% with HIV infection historically had diarrhea and either malabsorptive symptoms with villus atrophy or colitis resembling ulcerative colitis
● Even with HAART therapy, small bowel infections may still include cytomegalovirus, cryptosporidia, Mycobacterium avium complex (MAC) infections and Microsporidia (Hum Pathol 2010;41:1777, Rev Inst Med Trop Sao Paulo 2012;54:89)
Micro images
=========================================================================
Histopathologic features of HIV-associated GI pathology (small bowel and other GI sties)
Infectious disorders
Anisakis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 16 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Larvae of Ascarids (Anisakidae) are found in sea animals
● After ingesting contaminated raw fish or other sea food, larvae attach to mucosa of stomach or small intestine and cause ulceration, penetration or perforation
Life cycle
Case reports
=========================================================================
● 37 year old woman with epigastric pain two hours after ingesting fried hake and fish ova, and 200 larvae obtained by endoscopy (J Investig Allergol Clin Immunol 2010;20:437)
● 50 year old man with abdominal pain and peripheral eosinophilia after eating raw salmon from Pacific Ocean
(Am J Surg Pathol 2003;27:1167)
Clinical images
=========================================================================
Larvae in terminal ileum
Larvae in fish
Larvae in a herring
Micro description
=========================================================================
● Serositis, mucosal edema, submucosal abscess with eosinophils surrounding parasite with unpaired excretory gland (renette cell), Y-shaped lateral epidermal cords, no apparent reproductive system, and a ventriculus (glandular esophagus)
● No lateral alae, no ventricular appendage, no intestinal cecum
Micro images
=========================================================================
Larva in submucosa with eosinophils and lymphocytes
Larva in jejunum; note its intestinal lumen (L), the large lateral chords (LC) with a butterfly-like shape and many somatic muscle cells (MC); also a marked eosinophilic infiltrate with neutrophils and lymphocytes
Infectious disorders
Campylobacter
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 16 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Campylobacter jejuni is found in milk or poultry or transmitted from animal contact
● Invades small bowel and colon, causes dysentery or diarrhea
Micro description
=========================================================================
● Villous blunting, purulent exudates
Electron microscopy images
=========================================================================
Chacteristic corkscrew appearance
Infectious disorders
Capillariasis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 16 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Infection by nematode Capillaria philippinensis
● Described in Philippines, Thailand, Iran, Korea, Egypt
● May cause protein-losing enteropathy; worms infest jejunum and upper ileum
● Resembles trichuriasis
Life cycle
Diagnosis
=========================================================================
● Worms, eggs, larvae in stool
Case reports
=========================================================================
● 40 year old woman from India with diarrhea (Indian J Med Microbiol 2012;30:236)
Micro images
=========================================================================
Ovum (left, center) and adult female (right)
Infectious disorders
Clostridium
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 16 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
Clostridium difficile
● Causes bloody diarrhea after antibiotics (antibiotic associated colitis)
● Other risk factors include inflammatory bowel disease, colectomy with ileostomy or other bowel surgery (Anaerobe 2011;17:52)
● Due to cytotoxin, but locally invasive only
● Nosocomial spread
Clostridium perfringens
● Causes watery diarrhea
● Produces enterotoxin, and usually noninvasive
● Transmitted from meat, poultry, fish
Clostridium perfringens, type C strain
● Produces severe necrotizing enterocolitis of jejunum and ileum (enteritis necroticans) with perforation, also called pigbel, a pidgin English term for abdominal pain after a pig feast, reflecting a 1963 cluster of cases
● Occurred after World War II in previously starved children/adults after eating large meals of meat and vegetables
● Currently associated with severe protein malnutrition in Asia, Africa, South Pacific
● Rarely occurs in developed countries in patients with diabetes
● High mortality rate unless diagnose early and treat with antibiotics or surgical excision of necrotic bowel
● Preventative vaccine is available for toxin
Case reports
=========================================================================
● 66 year old woman with Type 2 diabetes mellitus who developed severe abdominal pain and bloody diarrhea from cooked turkey sausage (Mod Pathol 2002;15:66)
Clinical images
=========================================================================
Clostridium difficile enteritis 9 years after total proctocolectomy
Gross description
=========================================================================
● Segmental necrosis of proximal jejunum
Micro description
=========================================================================
● Ischemic changes with necrotic villi, inflammatory cells and fibrinoid necrosis of vessel
Micro images
=========================================================================
Various images
Crypt eruption and pseudomembranes
Infectious disorders
CMV
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● CMV infections associated with immunosuppression, HIV; usually reflects disseminated infection if present in gut
● May cause necrotizing injury and perforation
● CMV duodenitis may present with bleeding or ulceration
Micro description
=========================================================================
● Inclusions in endothelial cells, fibroblasts, smooth muscle cells
● Necrosis and granulation tissue associated with moderate/marked lymphoplasmacytic infiltrate (Scand J Gastroenterol 2011;46:1228 )
● Small bowel allografts: circumscribed area of mucosal injury with few eosinophils (Transplant Proc 2010;42:2671)
Micro images
=========================================================================
Various images
38 year old man with CMV pouchitis, post-surgery for ulcerative colitis; note nucleomegaly with intranuclear inclusions (courtesy of Dr. Hanni Gulwani)
Additional references
=========================================================================
●
Endoscopy 2007;39:E23,
J Clin Pathol 2006;59:1133
Infectious disorders
Cryptosporidium parvum
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Acid fast protozoa which causes self-limited disease in immunocompetent, but severe watery diarrhea resistant to most therapy in immunocompromised (J Biomed Res 2012;25:1)
Diagnosis
=========================================================================
● Acid-fast infective oocyst in stool
Micro description
=========================================================================
● 2-5 micron basophilic spherical structures attached to microvillus surface of epithelium
● Variable villus abnormality, may have eosinophils infiltrating mucosa
Micro images
=========================================================================
Various images
Positive stains
=========================================================================
● Giemsa, silver stains, PAS
Differential diagnosis
=========================================================================
● Mucin
● Cellular debris
Infectious disorders
Cyclospora cayetanensis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Coccidian parasite associated with municipal water systems, first report in late 1970's, causes protracted diarrhea (Clin Microbiol Rev 2010;23:218)
Diagrams
=========================================================================
Life cycle
Diagnosis
=========================================================================
● Oocyst in stool with modified acid-fast stain
Micro description
=========================================================================
● Resembles isospora
Micro images
=========================================================================
Various images
Electron microscopy images
=========================================================================
Several acid fast stained oocysts
Infectious disorders
Escherichia coli
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Causes traveler’s diarrhea (watery diarrhea, hemorrhagic colitis / hemolytic-uremic syndrome)
Different types of E. coli infection:
● Enterotoxigenic: cholera like, not invasive, from food or water, toxins activate adenylate cyclase and guanylate cyclase
● Enterohemorrhagic: shiga-like toxin, not invasive, from undercooked beef
● Enteropathogenic: enterocyte effacement, no invasion, from weaning foods, water; fatal diarrhea in newborns, colonize proximal small intestine
● Enteroinvasive: invasion and local spread, from cheese, water, person-to-person spread
● Enteradherent: noninvasive, adherent to epithelial brush border; chronic prolonged diarrhea, villous atrophy
Infectious disorders
Entamoeba histolytica
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Dysentery causing protozoa that can also cause fulminant colitis; causes up to 100,000 deaths per year (Trop Biomed 2011;28:194)
● Increased incidence in homosexual men and AIDS patients
Pathophysiology
=========================================================================
● Fecal-oral spread
● Amoeba invade colonic crypts, burrow into lamina propria, create flask shaped ulcer with broad base
● 40% invade portal vessels, embolize to liver and cause abscesses up to 10 cm
● May activate apoptosis in target cells (Trends Parasitol 2011;27:254)
● Rare abscesses in lung, heart, kidneys, brain
Life cycle
Micro images
=========================================================================
Various images
Amoebic colitis, numerous trophozoites of amoeba are noted (courtesy of Dr. Hanni Gulwani)
Amoebic colitis, PAS stain (courtesy of Dr. Hanni Gulwani)
Infectious disorders
Giardia lamblia
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Protozoan infection associated with malabsorption, chronic diarrhea
● Spreads by fecally contaminated water, common in underdeveloped countries
● Affects 1/3 of homosexual men in urban communities
● Attaches to mucosa but does not invade
● May cause endoscopic duodenal nodularity (Indian J Pathol Microbiol 2011;54:312)
● Causes epithelial barrier dysfunction by down regulating claudin 1 and increasing epithelial apoptoses (Gut 2007;56:328)
Life cycle
Diagnosis
=========================================================================
● Detect cysts, trophozoites or antigens in stool
Micro description
=========================================================================
● Variable villous blunting, increased inflammatory cells, organisms are teardrop (pear) shaped with paired nuclei in lumen between villi
● Size of organism is similar to enterocyte nuclei
Micro images
=========================================================================
Various images
Positive stains
=========================================================================
● Trichrome with iron hematoxylin counterstain, Giemsa stain
Infectious disorders
Isospora belli
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Coccidian parasite that infects epithelial cells of small intestine
● Causes chronic diarrhea and acalculous cholecystitis in AIDS patients (Indian J Med Res 2011;134:878)
Life cycle
Diagnosis
=========================================================================
● Cysts in stool, biopsy (H&E or EM)
Case reports
=========================================================================
● 35 year old HIV+ man (Indian J Pathol Microbiol 2010;53:824)
Micro description
=========================================================================
● Cysts present in parasitophorous vacuole in lamina propria (Hum Pathol 2001;32:500)
● Ovoid developmental forms are identified in and beneath epithelial cells near villus tip
Micro images
=========================================================================
Various images
Isospora belli (20-30 µm long by 10-19 µm wide) - immature oocyst (Modified acid fast stain)
Positive stains
=========================================================================
● Giemsa
Infectious disorders
Leishmaniasis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 18 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Intracellular protozoa that infects macrophages and may disseminate throughout reticuloendothelial system
Case reports
=========================================================================
● 27 year old man with intermittent night fever and abdominal pain (Iran Red Crescent Med J 2011;13:348)
● 33 year old man with AIDS, visceral leishmaniasis and mycobacterial infection (Arch Pathol Lab Med 1999;123:835)
Micro images
=========================================================================
Numerous foamy macrophages packed with microorganisms
Electron microscopy images
=========================================================================
Submucosal macrophage containing intracellular bacilli (long arrows) and protozoa
Infectious disorders
Microsporidia
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 18 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Caused by Enterocytozoon bieneusi, an obligate intracellular protozoan that affects only enterocytes and Encephalitozoon intestinalis, which infects macrophages, fibroblasts, endothelial cells, enterocytes
● Both cause chronic diarrhea in patients with immunosuppression, HIV
Diagnosis
=========================================================================
● Stool examination, PCR
Case reports
=========================================================================
● 33 year old woman with myeloma, post-autologous stem cell transplant and chemotherapy for relapse (Emerg Infect Dis 2012;18:1155)
● 43 year old man with pancreas/kidney transplant recipient and mullti-organ system dissemination (Arch Pathol Lab Med 2004;128:e41)
Treatment
=========================================================================
● Albendozole for E. intestinalis, nothing for E. bieneusi
Micro description
=========================================================================
● Minimal/no changes in mucosa but can find development spores as 1.5 mm dots in enterocytes
● May be surrounded by halos
● Also nucleated sporont present as 3-5 micron, rounded, basophilic structure often surrounded by a halo
Micro images
=========================================================================
Various images
Positive stains
=========================================================================
● Giemsa
Electron microscopy description
=========================================================================
● Often helpful for diagnosis
Infectious disorders
Mycobacteria
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 18 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
See also Tuberculosis
General
=========================================================================
● Aerobic and nonmotile bacteria without endospores or capsules that typically cause small bowel disease only in immunosuppressed or HIV+, usually as part of disseminated infection
Case reports
=========================================================================
● 31 year old woman with HIV and upper GI bleeding (Clin Infect Dis 2009;48:321, answer to quiz)
Micro description
=========================================================================
● Foamy macrophages fill lamina propria
● Usually patchy, no fat vacuoles
Micro images
=========================================================================
Disseminated Mycobacterium avium intracellulare complex (MAC) with nodular infiltration of duodenum
Acid-fast stain: site unspecified
Positive stains
=========================================================================
● PAS (faintly positive bacillary forms), acid-fast stains
Differential diagnosis
=========================================================================
Infectious disorders
Salmonella
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 18 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Bacterial causing food poisoning and typhoid fever (S. typhi)
● Typhoid fever: systemic dissemination with bacteremia, fever, chronic infection of joints, biliary tree, bones and meninges
● From contaminated milk, eggs, beef, poultry
● Usually affects terminal ileum
Gross images
=========================================================================
Various images
Micro description
=========================================================================
● Ulcers overlying Peyer’s patches with minimal inflammatory cells, chiefly mononuclear (plasma cells, histiocytes and lymphocytes)
● Often histiocytes with erythrophagocytosis
● May lead to perforation or toxic megacolon
Micro images
=========================================================================
Lymph node
Various images
Additional references
=========================================================================
● Science 2010;330:390,
Gut 1985;26:935
Infectious disorders
Strongyloides stercoralis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 20 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Nematode with complex life cycle that alternates between free-living and parasitic cycles, with potential for autoinfection and multiplication within host
Life cyclel
=========================================================================
● Larvae burrow into mucosa of duodenum and jejunum, where they mature into adults
● Females lay eggs, which develop into larvae that pass into stool, where they mature and become infective
● Infective larvae in soil penetrate intact skin, usually through feet
● Larvae enter circulatory system, are transported to lungs, enter alveolar spaces, are carried to trachea and pharynx, are swallowed and enter intestinal tract, where process is repeated
● If larvae become infective before leaving body, they may invade intestinal mucosa or perianal skin, causing autoinfection
Life cycle
Clinical features
=========================================================================
● Symptoms: none, diarrhea, malabsorption
● Severe/fatal infections in immunocompromised, due to worms moving from GI tract into other organs (WormBook. 2007 May 23:1-15.)
Diagnosis
=========================================================================
● Larvae in stool
● Adult female or eggs in small bowel mucosa, often with eosinophilic or granulomatous inflammation
Case reports
=========================================================================
● 43 year old Honduran man with diarrhea and abdominal pain (Case of the Week #133)
● 66 year old man with weakness and epigastric pain (Int J Prev Med 2012;3:370)
Treatment
=========================================================================
● Antihelminths such as thiabendazole (Ann Pharmacother 2007;41:1992)
● Prevent by wearing shoes in endemic areas
Micro images
=========================================================================
Case of the Week #133
Various images
Virtual slides
=========================================================================
Small intestine
Additional references
=========================================================================
● Arq Gastroenterol 2011;48:225
Infectious disorders
Tuberculosis
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Disease occasionally seen in less developed countries
● Small intestinal disease may be transmitted via contaminated milk
● Symptoms: abdominal pain, malabsorption, strictures, perforation, fistula
Sites
=========================================================================
● Terminal ileum, cecum, appendix
Gross description
=========================================================================
● Multiple and circumferential ulcers and strictures
Micro description
=========================================================================
● Confluent granulomas with central necrosis and peripheral lymphocytosis
● Destruction of muscularis propria, scarring
Micro images
=========================================================================
Granulomas in mucosa and submucosa
Ileocecal tuberculosis in 45 year old woman; epithelioid granulomas with Langhan’s giant cells in lamina propria (courtesy of Dr. Hanni Gulwani)
Ileocecal tuberculosis and adjoining draining lymph node (courtesy of Dr. Hanni Gulwani)
Positive stains
=========================================================================
● Acid-fast stains
Differential diagnosis
=========================================================================
● Crohn’s disease: linear and serpiginous ulcers; no bacteria identified (World J Gastroenterol 2011;17:433, BMJ Case Rep 2009;2009.1729)
Infectious disorders
Vibrio
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Vibrio cholerae, O1 or O139 serogroup, is noninvasive bacteria which produces enterotoxin causing watery diarrhea and cholera (Lancet 2012;379:2466)
● Transmitted via water, shellfish, person-to-person
● Spreads via pandemics
Electron microscopy images
=========================================================================
Various images
Infectious disorders
Whipple’s disease
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Rare systemic infection due to Tropheryma whippelii, a gram positive intracellular actinomycete (World J Gastroenterol 2009;15:2078)
● Usually affects proximal intestine, mesenteric lymph nodes
● Also called intestinal lipodystrophy
● Usually white males ages 30-49 years
Symptoms:
● Malabsorption with diarrhea, weight loss, abdominal pain
● Occasionally polyarthritis, CNS complaints, lymphadenopathy, hyperpigmentation
● Cardiac involvement less common
● Fatal without antibiotics
Pathophysiology
=========================================================================
Pathophysiology of Whipple's disease
Diagnosis
=========================================================================
● PCR, immunohistochemistry, PAS stain
Treatment
=========================================================================
● Antibiotics
● Relapses are common
Gross description
=========================================================================
● Shaggy mucosa, edematous bowel wall
Micro description
=========================================================================
● Distended macrophages in lamina propria containing PAS+ granules and rod shaped bacilli by EM
● Dilated lymphatics or fat vacuoles
● Often multinucleated giant cells; rarely epithelioid granulomas in minority
● In mesentery or retroperitoneal nodes, resembles lipogranulomatous inflammation with round empty spaces
Note:
● After treatment, macrophages decrease in lamina propria but remain present elsewhere for years; cytoplasmic inclusions become tissue-paper like with PAS, resembling Gaucher’s cells
Micro images
=========================================================================
Various images (contributed by Drs. Derek Mathis and Rosemarie Rodriguez, San Antonio Uniformed Services Health Education Consortium, San Antonio, Texas)
PASD images (contributed by Drs. Derek Mathis and Rosemarie Rodriguez, San Antonio Uniformed Services Health Education Consortium, San Antonio, Texas)
Positive stains
=========================================================================
● PAS, anti-T Whippelii immunostain (Hum Pathol 2003;34:589)
Electron microscopy description
=========================================================================
● Rod-shaped bacteria
Differential diagnosis
=========================================================================
● Histoplasmosis: faint blue dot-like inclusions surrounded by a clear halo, PAS or silver stain shows budding yeast
● Mineral oil ingestion
● Mycobacterium avium-intracellulare infection: immunocompromised patients, patchy infection, no lipid vacuoles, PAS shows faintly positive bacillary forms
Infectious disorders
Yersinia
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Common cause of bacterial enteritis in US, Canada, Australia, Western Europe, Northern Europe (eMedicine)
● Infection due to Y. enterocolitica, Y. pseudotuberculosis, gram negative invasive rods
● Bacteria present in infected milk, pork, water supplies, domestic pets and farm animals
● Causes enterocolitis, acute appendicitis, mesenteric lymphadenitis in children and adolescents
● Pathogenic strains invade small intestinal mucosa via M cells overlying Peyer’s patches, multiply there and within regional nodes, then spreads hematogenously and via lymphatics
● Patients homozygous for Thalassemia major are at risk of Y. enterocolitica, because they have iron overload and the bacteria require iron for growth
Sites
=========================================================================
● Ileum, right colon, appendix
Diagnosis
=========================================================================
● Culture
Case reports
=========================================================================
● 4 year old boy with intussusception due to Y. enterocolitica infection
(Arch Pathol Lab Med 2001;125:1486)
Micro description
=========================================================================
● Elongated ulcerations overlying lymphoid hyperplasia
● Also small aphthoid ulcers overlying colonies of gram negative rods and with neutrophils at ulcer base
● Also necrotizing granulomas (particularly with Y. pseudotuberculosis)
● Mesenteric nodes show follicular hyperplasia with variable scattered microabscesses and epithelioid granlomas
Micro images
=========================================================================
Various images
Differential diagnosis
=========================================================================
● Crohn’s disease
● Mycobacteria
● Typhoid fever
Obstruction
Obstruction-general
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 18 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Mechanical causes: adhesions, atresia, bands, congenital stricture (children), fecaliths, foreign bodies, gallstones, hernias, inflammation, intussusception, mesenteric ossification (Am J Surg Pathol 1999;23:1464), systemic disease (diabetes, scleroderma), tumors, volvulus
● Disturbances in peristalsis: Hirschsprung’s, ileus-postoperative paralytic, myopathy
● 80% due to hernias, intestinal adhesions, intussusception, volvulus
● May cause stasis, with resulting malabsorption
● Symptoms: distension, failure to pass flatus, pain, vomiting
Treatment
=========================================================================
● Dietary changes, medication (octreotide), surgery, intestinal transplantation
Micro description
=========================================================================
● Patchy mucosal changes of variable villus abnormality, increased chronic inflammatory cells in epithelium and lamina propria, occasional neutrophils
Obstruction
Adhesions
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 12 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Adhesions develop between bowel segments or abdominal wall and operative site
● May create internal herniations (closed loops through which viscera slide)
● Rarely adhesions are congenital
Etiology
=========================================================================
● Post-operative, infections, endometriosis
Clinical images
=========================================================================
Adhesions between loops of small intestine
Obstruction
Chronic idiopathic intestinal pseudo-obstruction
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 18 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Symptoms of intestinal obstruction without mechanical obstruction
● Attributed to abnormal physiology of gut propulsive system
Etiology
=========================================================================
● Local manifestation of generalized disease: diabetes, hypoparathyroidism, Parkinson’s disease, SLE
● Diseases with intestinal pathology: amyloidosis, Chagas’ disease, dermatomyositis/polymyositis, Duchene’s muscular dystrophy, myotonic dystrophy, myxedema, scleroderma
● Also drugs (anti-Parkinson, clonidine, mushroom poisoning), pheochromocytoma, psychosis,
● May be due to marked reduction in interstitial cells of Cajal (Am J Surg Pathol 2003;27:228)
● By definition, excludes known mechanical causes of obstruction: cathartic colon, ceroidosis, Hirschsprung’s disease, visceral myopathies (muscle cell degeneration/loss, fibrosis of muscularis propria), visceral neuropathies (familial-Am J Surg Pathol 2010;34:1528, sporadic; require special techniques to demonstrate)
Obstruction
Hernias
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 18 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Protrusion of pouchlike, serosa-lined sac of peritoneum (hernia sac) through weakness or defect in wall of peritoneal cavity
● Usually inguinal and femoral canals, umbilicus and surgical scars
● Rarely around ligament of Trietz
● Viscera may protrude and become trapped in hernias, including bowel loops and omentum
● Complications: incarceration, strangulation, infarction
Gross images
=========================================================================
Various images
Obstruction
Scleroderma
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 18 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Also called progressive systemic sclerosis
● GI manifestations in 50-90% (Rheumatology (Oxford) 2009;48:iii36)
● May cause malabsorption syndrome (related to bacterial overgrowth), intestinal pseudo-obstruction (Presse Med 2006;35:1952)
Micro description
=========================================================================
● Dense fibrosis replacing entire muscularis propria or accentuated in inner layer
● No vacuolar change
Obstruction
Volvulus
Reviewer: Hanni Gulwani, M.D. (see Reviewers
page)
Revised: 17 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.
General
=========================================================================
● Complete twisting of a loop of bowel about its mesenteric base of attachment
● Produces intestinal obstruction and infarction
● Usually in redundant loops of bowel
Case reports
=========================================================================
● 4 year old boy with midgut volvulus (Int J Emerg Med 2010;3:523)
● 17 year old boy with 10 year history of nonspecific GI symptoms, and midgut malrotation (N Am J Med Sci 2012;4:196)
Diagrams
=========================================================================
Volvulus
Gross images
=========================================================================
Small bowel volvulus and necrotic bowel
End of Small bowel (small intestine) > Superpage > Nontumor
This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.
All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com
with any questions (click here for other
contact information).