Primary carcinoid tumor of the cystic and common bile ducts.

We report a case of primary carcinoid tumor arising at the confluence of the cystic and common bile ducts. The patient was a 64-year-old woman who developed a sudden onset of biliary colic and jaundice. Computerized tomography and nuclear magnetic resonance showed a mass lesion close to the head of the pancreas. At laparotomy a nodular lesion was found at the confluence of the cystic and common bile ducts. Microscopic observation revealed a type B-C carcinoid (Soga's classification) with positive immunoreactivity to chromogranin and cytokeratin. The presence of neurosecretory intracytoplasmic granules was demonstrated by electron microscopy. Flow cytometry showed diploid DNA content of the neoplastic cells with less than 5% of the nuclei in the S-phase region.