Diffuse Gallbladder Adenomyomatosis in a Child.

Adenomyomatosis of the gallbladder is a benign condition, usually occurring in middle age, in which the epithelium of the gallbladder proliferates and the gallbladder wall thickens with the presence of Rokitansky-Aschoff sinuses (RAS). The diffuse form is an unusual subtype of adenomyomatosis. Herein, we describe a 17-year-old female who presented with dull and intermittent pain in the right hypochondriac region for more than a month. Ultrasound followed by magnetic resonance imaging showed marked diffuse gallbladder wall thickening. A gross cholecystectomy specimen showed a diffusely enlarged gallbladder. The final diagnosis of gallbladder adenomyomatosis (GA) was confirmed by the histopathologic appearance of muscular and epithelial hyperplasia, contributing to mural thickening with epithelial invaginations forming the pathognomonic intramural diverticula known as the RAS. This case highlights that the diffuse form of GA is uncommon and is often accompanied by chronic inflammation, sometimes requiring differential diagnosis from gallbladder malignancies, especially when there is no image showing a "comet tail" of cholesterol crystals in the wall.