Definition: Small outpouchings of gallbladder mucosa that extend through the muscularis layer. It may be congenital.
Rokitansky-Aschoff sinuses (R-As) are epithelial invaginations that extend down the gallbladder wall through the smooth muscle gaps and by this pathway they reach the subserosal connective tissue.
Sinuses in the gallbladder. Normally occurring, microscopic pouches of the mucosa of the gallbladder. They may reach into and through the muscle wall. Prominence in the settings of inflammation and gallstone formation (e.g. chronic cholesystitis) suggest that they are acquired herniations.
References
Mucin-containing Rokitansky-Aschoff Sinuses With Extracellular Mucin Deposits Simulating Mucinous Carcinoma of the Gallbladder. Albores-Saavedra J, Galliani C, Chable-Montero F, Batich K, Henson DE. Am J Surg Pathol. 2009 Sep 4. PMID: 19738458
Albores-Saavedra J, Shukla D, Carrick K, Henson DE. In Situ and Invasive Adenocarcinomas of the Gallbladder Extending Into or Arising From Rokitansky-Aschoff Sinuses: A Clinicopathologic Study of 49 Cases. Am J Surg Pathol. 2004 May;28(5):621-628. PMID: 15105650