Abstract
A 71 year old woman underwent distal pancreatectomy and splenectomy for ductal carcinoma and an associated large cyst of the pancreas tail. Preoperative differential diagnosis from cystadenocarcinoma was difficult because the cyst did not communicate with the main pancreatic duct, there was a papillary projection at the cyst wall, and the boundary between the cyst wall and the tumor mass was not clearly defined by endoscopic ultrasonography. Pathologic examination of the resected specimen showed that the tumor was a conventional papillo-tubular adenocarcinoma and that it constituted part of the wall of the retention cyst. Though this is a rare combination, the situation should be kept in mind to differentiate it from cystadenocarcinoma.
