A Case of Serous Cystadenoma Communicating with a Stenotic Santorini’s Duct and a Dilated Main Pancreatic Duct

Abstract

A 59-year-old woman was referred for investigation of a pancreatic cystic lesion. Computed tomography revealed a well-demarcated, multilocular cyst, approximately 4 cm in size, at the pancreas head. Endoscopic ultrasonography demonstrated honeycomb-like components at the cyst margin. The cyst was associated with a widely-dilated upstream main pancreatic duct (MPD). Endoscopic retrograde pancreatography demonstrated a communication between the stenotic Santorini‘s duct and the cyst. Aspiration cytology from the cyst demonstrated clusters of mucinous epithelial neoplasm cells. Branch-type intraductal papillary mucinous neoplasm, possibly invading to the MPD, was suspected and pancreatoduodenectomy was performed. Surprisingly, pathology of the resected pancreas showed mixed-type serous cystadenoma. Abbreviations: CA19-9: cancer antigen 19-9; CEA: carcinoembryonic antigen; ERC: endoscopic retrograde cholangiography; ENPD: endoscopic naso-pancreatic drainage ; ERP: endoscopic retrograde pancreatography; EUS: endoscopic ultrasonography; NET: neuroendocrine tumor; FNA: fine needle aspiration; IPMN: intraductal papillary mucinous neoplasm; MRCP: magnetic resonance cholangiopancreatography; MPD: main pancreatic duct; SCA: serous cystic neoplasms.