Adenomyomatosis of gall bladder is seen in 2% - 5% of cholecystectomies. It presents either as a diffuse wall thickening (adenomyomatous hyperplasia) or as a localized or focal lesion of the gall bladder (adenomyoma) which may mimic gall bladder carcinoma. Adenomyomas are most often located in the fundus of gall bladder and the usual size described is 1-2 cm. Herein we report a case of adenomyoma of the gall bladder which presented as an unusually large polypoidal mass measuring 7.8x6x4 cm and located in the neck region of gall bladder thus clinically and radiologically mimicking malignancy. Although adenomyomas can present as a pseudotumour in the gall bladder, our search of literature revealed this to be the the first case of adenomyoma of such a large size and situated in the neck of gallbladder.

Keywords: Gallbladder; Giant; Adenomyoma; Pseudotumour; Polyp.