A Resected Gallbladder Carcinoma Coexisting With Adenomyomatosis Involving Varied Degrees of Intraepithelial Dysplasia: A Case Report and Literature Review

A 59-year-old asymptomatic man underwent ultrasonography, which revealed gallstones and thickened gallbladder wall. Abdominal computed tomography (CT) showed a slightly swollen bilocular gallbladder and a soft tissue mass in the fundus site. Segmental adenomyomatosis (ADM) was suspected because numerous fundic cystic lesions were seen on magnetic resonance imaging. Endoscopic ultrasonography revealed numerous Rokitansky-Aschoff sinuses (RAS) and a papillary soft tissue shadow surrounded with irregular and remarkably thickened fundic gallbladder wall. Fluoro-2-deoxy-D-glucose-positron emission tomography/CT demonstrated slightly increased fluoro-2-deoxy-D-glucose uptake in the corresponding lesion. Surgery was performed under a diagnosis of gallbladder carcinoma (GBC) with concomitant ADM, and histopathology revealed a 30-mm papillotubular adenocarcinoma extending from the gallbladder body to fundus with invasion into the subserosa. Numerous RAS were present throughout the gallbladder showing various degrees of dysplasia. Ki67 and p53-labeling index (LI) was significantly higher in the dysplastic epithelium compared with normal fundic epithelium. p53-LI was also markedly increased (72.1%) in tissue in front of tumor invasion. Interestingly, these hyperproliferation indicators were extremely high (Ki67-LI: 28.8%; p53-LI: 91.9%) in RAS with low-grade dysplasia even in the gallbladder neck. Although, generally, tumors do not develop in the gallbladder neck with segmental ADM, our results suggest that a gallbladder with ADM has potential for carcinogenesis regardless of location, with segmental ADM. On the basis of histopathology, our patient was diagnosed with GBC arising from RAS with multicentric and multistep growth. A relationship between GBC and ADM, especially segmental ADM, has been suggested but remains controversial. Our experience is very suggestive of carcinogenesis developing from ADM.