[Carcinoid of the digestive tract. An analysis of 36 cases]

36 cases of carcinoid of the digestive tract were presented. The malignancy of the carcinoid was established solely by the presence of local infiltration and remote metastasis irrespective of the size of the original tumor three of 10 cases of the tumor less than 2 cm in diameter had metastasis although smaller tumors were usually benign. Immuno-histochemistry study in 15 cases showed 1-4 kinds of different polypeptides in each case. Three of 8 cases of malignant carcinoid syndrome had normal blood level of 5-HT and 5-HIAA, suggesting other polypeptides as the cause of the syndrome. The absence of hepatic metastasis in 4 of the 8 cases favors the hypothesis that polypeptides may get access to the general circulation by such as retroperitoneal pathways.