Clinical and experimental studies on a midgut carcinoid tumor

This study reports on a patient with a midgut carcinoid discovered due to the occurrence of a subcutaneous metastasis that caused symptoms. The histopathologic diagnosis of a carcinoid was confirmed by light and electron microscopic and immunocytochemical examination of the metastasis. The primary ileal tumors were only localized after the determination of serotonin in platelet-poor plasma/whole blood sampled at selective mesenteric vein catheterization. Tumor cells from lymph node metastases were studied in vitro, in intraocular heterotransplants, and in cell culture.