adenomyomatous hyperplasia of gallbladder
adenomyomatous hyperplasia of gallbladderA usually benign alteration of the gallbladder, which occurs in nearly 9% of cholecystectomy specimens; it is more common in women. While dysplastic changes and in situ and invasive carcinomas may arise in adenomyomatous hyperplasia, carcinogenesis is attributed to stones, chronic inflammation and metaplasia rather than adenomyomatous hyperplasia per se.
Most patients present with chronic right upper quadrant pain; 90% have coexistent gallstones.
• Localised type—The most common type; characterised by a well-formed, typically semilunar or crescent-shaped mass in the gallbladder fundus. Cut sections have a honeycombed appearance due to multiple, small cystic spaces which correspond to prominent epithelial invaginations (Rokitansky-Aschoff sinuses or intramural diverticula).
• Segmental type—Characterised by focal circumferential thickening of the gallbladder wall, typically in the body of the gallbladder, giving it an hourglass configuration on gross inspection.
• Diffuse type—Characterised by diffuse gallbladder wall thickening with intramural diverticula that appear as cystic spaces within the wall.