A retroperitoneal endocrine carcinoma.

A case of endocrine carcinoma in the retroperitoneal cavity of a 41-year-old woman is reported. Tumor cells were negative for argentaffin and positive for argyrophil reactions. Immunohistochemically, vasoactive intestinal polypeptide, hCG-alpha, and somatostatin were identified. Electron microscopically, numerous secretory granules measuring 210 to 280 nm in diameter and with distinct limiting membranes were seen in the tumor cells. Discussion was focused on the origin of endocrine tumor cells in the retroperitoneal cavity.