Epithelial cyst of the gallbladder associated with adenocarcinoma.

Epithelial cyst of the gallbladder associated with papillary adenoma and adenocarcinoma is presented herein. A 70-year-old male patient with general malaise was admitted to our hospital during the follow-up of an elevated mucosal lesion in the fundus of the gallbladder. Endoscopic ultrasonography revealed a cystic lesion adjacent to the elevated lesion, and interruption of the hyperechoic third layer of the gallbladder wall next to the gallbladder bed of the liver. He was diagnosed as having an epithelial cyst of the gallbladder associated with gallbladder carcinoma that directly invaded the gallbladder bed. He underwent resection of the gallbladder with partial resection of the liver and regional lymph node dissection. The resected specimen, which showed multiple cysts with septum formation, measured 1.9 cm in size and was located in the subserosal layer of the gallbladder wall. The wall of the cyst was lined with columnar epithelium and papillary adenoma, and adenocarcinoma was scattered in some portions of the cyst wall. Furthermore, papillary adenoma associated with adenocarcinoma was independently identified in the luminal surface of the gallbladder epithelium covering the cysts. These histological findings were compatible with epithelial cyst of the gallbladder associated with papillary adenoma and adenocarcinoma. The tumor was diagnosed as T1bN0M0, stage I, in the TNM clinical classification. To our knowledge, this is the first report of an epithelial cyst of the gallbladder associated with papillary adenoma and adenocarcinoma, and provides some insight into the relationship between epithelial cyst and adenoma or cystadenocarcinoma of the gallbladder.