Production of several substances by medullary carcinoma of the thyroid.

Two patients with the typical morphology of medullary carcinoma of the thyroid are reported. Biochemical analysis of the tumor tissue demonstrated the presence of calcitonin, ACTH and MSH, although symptoms referable to these hormones were hardly manifested. Serum CEA levels were elevated and CEA immunofluorescences in the tumor cells were positive. Moreover, in one patient, serotonin concentration was raised in the tumor tissue, and gastrin level was also elevated in the peripheral blood. These results suggest that the tumors may produce several substances.