Gallbladder & extrahepatic bile ducts
General
Histology-gallbladder
Author: Hanni Gulwani, M.B.B.S.
Topic Completed: 1 September 2012
Minor changes: 30 December 2020
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: Gallbladder histology[TIAB]
Table of Contents
Definition / general | Terminology | Physiology | Microscopic (histologic) images | Positive stainsCite this page: Gulwani H Histology-gallbladder. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/gallbladderhistology.html. Accessed January 16th, 2021.
Definition / general
- Has mucosa, muscularis propria and serosa on free surface
- No muscularis mucosa or submucosa is present
Terminology
Mucosa:
Surface epithelium:
Lamina propria:
Muscular layer:
Adventitia:
Peritoneum:
Aberrant bile ducts (ducts of Luschka):
Rokitansky-Aschoff sinuses:
Larger accessory bile ducts:
Mucin secreting accessory glands:
- Variable branching folds, more prominent if gallbladder not distended
Surface epithelium:
- Composed of single layer of uniform, tall columnar cells with basal nuclei, indistinct nucleoli, pale cytoplasm due to sulfomucins
- Few PAS+ apical vacuoles; also pencil cells (small, darkly staining columnar cells), inconspicuous basal epithelial cells, T lymphocytes
- No goblet cells, myoepithelial cells or melanocytes
- Neck region has tubuloalveolar mucus glands that secrete sulfo, sialo and neutral mucin and contain neuroendocrine cells
- True glands are not present outside the neck
Lamina propria:
- Loose connective tissue with blood vessels, lymphatics, occasional chronic inflammatory cells (IgA secreting plasma cells), no neutrophils
Muscular layer:
- Circular, longitudinal and oblique smooth muscle fibers without distinct layers, resembles muscularis mucosa
- Adjacent to lamina propria without an intervening submucosa
Adventitia:
- Perimuscular connective tissue composed of collagen, elastic tissue, fat, vessels, lymphatics, nerves, paraganglia
Peritoneum:
- Lines gallbladder that is not directly attached to liver, is continuous with that of liver
Aberrant bile ducts (ducts of Luschka):
- Present in 10% of cholecystectomy specimens, often buried in gallbladder wall adjacent to liver, may contain collar of fibrous tissue, may communicate with intrahepatic bile ducts
- Histologically composed of lobular aggregates of small ductules lined by bland cuboidal to columnar biliary type epithelium (Am J Surg Pathol 2011;35:883)
Rokitansky-Aschoff sinuses:
- Outpouchings of gallbladder mucosa that penetrate into muscle wall
- May be acquired herniations
Larger accessory bile ducts:
- Join with cystic or hepatic ducts, may be present within gallbladder bed
Mucin secreting accessory glands:
- Prominent near terminus of common bile duct
Physiology
- Bile excretion is normally 500 - 1000 ml/day
- Bile is concentrated 5 - 10x via active absorption of electrolytes accompanied by passive movement of water
- Cholecystokinin causes gallbladder contraction and release of stored bile into gut
- Bile is critical for intestinal absorption of dietary fat but the gallbladder is not
- Bile is 2/3 bile salts, bicarbonate rich, has 3% organic solutes
- 95% of secreted bile salts is reabsorbed in ileum and returned to liver via portal blood, called enterohepatic circulation of bile salts
- Cholesterol is eliminated by loss of 0.5 g of bile salts per day>
- Cholates, chenodeoxycholates, deoxycholates, lithocholates, ursodeoxycholates
- Major hepatic products of cholesterol metabolism
- Family of water soluble sterols with carboxylated side chains
- Are highly effective detergents, solubilize water insoluble lipids secreted by the liver (usually lecithin) into the biliary tree and promote dietary lipid absorption within the gut
Lecithin (phosphatidylcholine):
- Hydrophobic, nonaqueous
- Has minimal solubility in water
Microscopic (histologic) images
Images hosted on other servers:
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Cross section
Positive stains
- Surface epithelium: EMA, low molecular weight keratin, alpha-1-antitrypsin, alpha-1-antichymotrypsin, polyclonal CEA
