2020 Volume 34 Issue 1 Pages 89-95
Adenomyomatosis (ADM) of the gallbladder is a benign, acquired lesion characterized by proliferation of the Rokitansky-Aschoff sinus (RAS) with epithelial and muscular hypertrophy. ADM is classified into diffuse, segmental, fundal, and mixed type according to its distribution. In this manuscript, gallbladder ADM is described mainly from the viewpoint of pathology, and ADM cases experienced in our institution have been summarized. It is noteworthy that muscular hypertrophy is seen in ADM, but a RAS-surrounding pattern is undetectable. In segmental type ADM, muscular hypertrophy is sometimes more marked at the fundal side than at the ADM site. In fundal type ADM, the grossly detectable central pit is comprised of the depressed gallbladder wall itself and not of the RAS. The pathogenesis of ADM has not been formally established, although there seems to be a consensus on the histological step from RAS to ADM. Current data does not support ADM as a precursor lesion of gallbladder carcinoma, although several authors have reported ADM, particularly segmental ADM, as a risk factor. The collection of further evidence regarding ADM pathology is required.
