Adenomyomatosis Concomitant with Primary Gallbladder Carcinoma.

Some clinicians have proposed a relationship between gallbladder (GB) cancer and adenomyomatosis (ADM) of the gallbladder, although the latter condition is not considered to have malignant potential. We retrospectively reviewed the surgical pathology database of patients who underwent resection for ADM of the gallbladder at our institution from March 2005 to May 2015. In total, 624 patients underwent surgical resection of the gallbladder with Rokitansky-Aschoff sinuses. Of these cases, 93 were pathologically diagnosed with ADM of the gallbladder, with 44 (47.3%) classified macroscopically as fundal-type ADM, 26 (28.0%) as segmental type, and 23 (24.7%) as diffuse-type ADM. In 3 of the 93 (3.2%) resected specimens, early-stage GB carcinoma was detected, although preoperative imaging did not suggest a malignant neoplasm of the gallbladder in any of these patients. GB cancer subsequently developed in the mucosa of the fundal compartment distal to the annular stricture of the segmental-type ADM in 2 of these patients and against the background of the fundal-type ADM in 1 patient. This study revealed the difficulty of early diagnosis of primary GB cancer in the setting of concurrent ADM, and clinicians should be aware of this frequent coexistence.