Undifferentiated carcinoma of the pancreas involving intraductal pedunculated polypoid growth.

We herein report a case of pancreatic undifferentiated carcinoma involving intraductal pedunculated polypoid growth. Duodenoscopy disclosed a congested polypoid mass protruding from the orifice of the papilla of Vater. Endoscopic retrograde pancreatography (ERP) showed a polypoid lesion in Wirsung's duct and Santorini's duct. Pancreatic juice cytology using the cell block method revealed the presence of undifferentiated carcinoma. No extraductal invasion was detected on endoscopic ultrasonography and or intraductal ultrasonography. The patient therefore underwent pancreaticoduodenectomy. A histological examination revealed an intraductal polypoid tumor with a thin stalk without extraductal invasion. The tumor was composed of an abundant mixture of pleomorphic cells, spindle cells, giant cells, and a small amount of adenocarcinoma.