Gallbladder & extrahepatic bile ducts
General
Anatomy, histology & embryology


Topic Completed: 1 September 2012

Minor changes: 17 April 2021

Copyright: 2003-2021, PathologyOutlines.com, Inc.

PubMed Search: Gallbladder histology[TIAB]

Hanni Gulwani, M.B.B.S.
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Cite this page: Gulwani H Anatomy, histology & embryology. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/gallbladderhistology.html. Accessed May 11th, 2021.
Definition / general
  • Has mucosa, muscularis propria and serosa on free surface
  • No muscularis mucosa or submucosa is present
Anatomy
  • Pear shaped saccular structure for bile storage in gallbladder fossa of posterior right hepatic lobe
  • Attached to liver by loose connective tissue and to duodenum by cholecystoduodenal ligament
  • 10 x 4 cm but depends on volume of bile (normal 40 - 70 ml)
  • Wall thickness 1 - 2 mm
  • Has fundus, body and neck
  • Distal fundus: extends beyond anterior liver margin

  • Central body: most of gallbladder
  • Neck: narrows as it joins the cystic duct
  • Cystic duct: 3 cm tubular structure, located in right free edge of lesser omentum, has spiral valve of Heister
  • Infundibulum: portion of body that joins the neck
  • Hartmanns pouch: dilation in infundibulum, may be due to chronic inflammation

  • Vasculature: supplied by cystic artery, usually a branch of right hepatic artery; variations of arteries may be dangerous during surgery
    • Right and left hepatic ducts:
      • 3 - 4 mm in diameter, within hepatoduodenal ligament, join to form common hepatic duct in porta hepatis (hilum of liver) within 1 cm of their exit from liver; variations may be dangerous during surgery
      • 10 - 30% have variation of 2 right sided ducts that join separately with left hepatic duct, common hepatic duct or cystic duct

    Common hepatic duct:
    • 2 - 8 mm, 1 - 5 cm long, joins cystic duct (1 - 3 cm long) to form common bile duct

    Common bile duct:
    • 2 - 9 cm long, passes posterior to first portion of duodenum, traverses the head of pancreas, enters the second part of duodenum through the ampulla of Vater and discharges gallbladder contents into duodenal lumen
    • 60% have common channel for pancreatic duct and common bile duct
    • Remainder have 2 ducts in parallel

    Cystic duct:
    • Attaches gallbladder to extrahepatic bile duct, marks division between common hepatic duct and common bile duct
    • Usually 2 - 4 cm
    • Contains spiral valves of Heister

    Sacculi of Beale:
    • Tiny pits that are infoldings of surface epithelium and give mucosa a reticular macroscopic appearance

    Spiral valves of Heister:
    • Folds in proximal mucosa of cystic duct, supported by underlying smooth muscle fibers
    • Regulates degree of gallbladder distension
    • Regional lymph nodes: lymph node present at gallbladder neck or cystic duct drains to hepatic hilar nodes (along common bile duct, hepatic artery, portal vein, cystic duct); also celiac, periduodenal, peripancreatic and superior mesenteric nodes
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>

Bile salts:
  • 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
Diagrams / tables

Images hosted on other servers:

Relationship to liver

Extrahepatic bile ducts

Micro description - gallbladder
Mucosa:
  • 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
Micro description - extrahepatic bile ducts
Surface epithelium:
  • Composed of tall, uniform, columnar cells
  • Mucosa forms irregular pleats or small longitudinal folds

Peribiliary mucous glands:
  • Considered a local progenitor cell niche in extrahepatic biliary epithelium (Liver Int 2012;32:554)
  • Unevenly distributed within large intrahepatic ducts and all extrahepatic bile ducts
  • Lobular architecture; are surrounded by fibroconnective tissue (important in differentiating from well differentiated carcinoma)

Subepithelial region:
  • Dense, hypocellular connective tissue, few lymphocytes
  • Overlies loose connective tissue with elastic fibers and smooth muscle fibers that are most prominent distally but absent or sparse proximally

Muscle layer:
  • Not well defined until distal common bile duct / lower 1/3 of extrahepatic bile duct (Am J Surg Pathol 2000;24:660)
  • Upper 1/3 has no muscle layer or scattered muscle fibers
Microscopic (histologic) images

Images hosted on other servers:

Cross section of gallbladder


Extrahepatic bile duct and gallbladder

Positive stains
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