NEUROENDOCRINE CARCINOMA OF THE EXTRAHEPATIC BILIARY-TRACT WITH POSITIVE IMMUNOSTAINING FOR GASTRIN-RELEASING PEPTIDE - REPORT OF A CASE

We report herein the first documented case of gastrin-releasing peptid e-positive neuroendocrine (NE) carcinoma of the extrahepatic biliary t ract. An invasive tumor measuring 2.5 x 1.5 cm was located in the conf luence portion of the cystic duct in a 70-year-old Japanese man. Histo logically, the tumor was found to be composed of small polygonal cells which formed a solid and trabecular structure, and the frequencies of both mitoses and small necrotic areas were dominant. The tumor cells were immunoreactive to the NE markers chromogranin-A and neuron-specif ic enolase, as well as to carcinoembryonic antigen and gastrin-releasi ng peptide. Although a few cases of gastrin-releasing peptide-positive small-cell lung carcinoma have been documented, there have been no re ports of gastrin-releasing peptide-positive NE carcinoma occurring in the gastrointestinal tract. We consider our case not merely to be of p athological interest, but also to have clinical and therapeutic implic ations.