Mucin-hypersecreting tumor of the pancreas with mucin extrusion through an enlarged papilla.

Patient records, imaging films, macroscopic and microscopic features, and clinical follow-up data of seven Japanese patients with a mucin-hypersecreting tumor of the pancreas were reviewed. The mucin-hypersecreting tumor was defined as an enlarged major or minor papilla with a dilated orifice and visible mucin oozing on endoscopy. The series consisted of six men and one woman ranging from 47 to 79 yr old. The excretion of mucin through a patulous orifice of the enlarged ampulla of Vater was seen in six patients and of the enlarged minor papilla in the other patient with pancreas divisum. The main pancreatic duct was dilated in all patients. Amorphous mucin was seen in the dilated duct of five patients, and papillary nodules were present in two patients. Computed tomography and/or ultrasonography showed dilatation of the main pancreatic duct with multilocular cysts in six patients and with a solid tumor in the other patient. The tumor was located diffusely in the main pancreatic duct in one patient, whereas it was confined to branches in the head (four patients), body (one patient), or tail (one patient) of the pancreas in the six other patients. Histopathologic diagnosis was a cyst lined by hyperplastic mucus-secreting epithelium in one patient, mucinous cystadenoma in two, and mucinous cystadenocarcinoma in two. Five patients underwent resection and have survived for 1-46 months after the operation. The authors would like to emphasize this endoscopic syndrome because about half of mucin-hypersecreting tumors are malignant with a favorable prognosis.