Gangliocytic paraganglioma of the duodenum: an immunocytochemical study.

Two cases of duodenal paragangioliomas that were studied using light microscopy and immunocytochemical methods are reported. The tumors showed immunoreactivity to somatostatin, cholecystokinin, calcitonin, gastrin, vasoactive intestinal polypeptide, serotonin, met-enkephalin, leu-enkephalin, and substance P. The similarities of duodenal paragangioliomas to other neoplasms occurring in similar anatomic locations are outlined.