Serotonin-secreting and insulin-secreting ileal carcinoid tumor and the use of in vitro culture of tumoral cells.

The authors report the case of a patient with a typical carcinoid syndrome and a severe hypoglycemia due to hyperinsulinism. He was found to have an ileal carcinoid tumor with hepatic metastasis and no evidence of pancreatic insulinoma at surgery and autopsy. By assaying serotonin and insulin in the tumor and in the supernatants of the culture derived from hepatic metastasis, the authors have been able to show that both hormones were produced by the carcinoid tissue. Cultured cells also synthesized minute amounts of gastrin and thyrocalcitonin.