Ileal carcinoid tumor complicating carcinoid heart disease and secondary retroperitoneal fibrosis

A 70-year-old man with metastatic liver tumors showed carcinoid syndrome wi th clinical symptoms of facial flushing, palpitation, dyspnea, and an itchi ng sensation. Regurgitation of the tricuspid and aortic valves was observed by echocardiography. An elevated serum level of serotonin and a high urine excretion of serotonin metabolites were confirmed. Autopsy confirmed a ser otonin-immunoreactive 1 cm ileal carcinoid tumor with metastasis to the liv er, bone and peritoneum. The tumor cells were argyrophilic but not argentaf fin, and showed erythrophagocytosis in the primary lesion. All the four hea rt valves and bilateral atrial endocardium showed fibromyxoid thickening, i ndicating the association of carcinoid heart disease. Desmoplastic reaction with deposition of sulfated acid mucopolysaccharides was also observed in the retroperitoneal space (secondary retroperitoneal fibrosis). Stenosis of the bilateral ureters and inferior mesenteric artery provoked hydronephros is and lethal ischemic necrosis of the left-sided colon, respectively. Rari ty of functioning ileal carcinoid tumor and pathogenesis of systemic fibrop lasia are discussed.