Concentrations of Calcitonin and Catecholamines in Pheochromocytomas, a Mucosal Neuroma and Medullary Thyroid Carcinoma1

Two patients with the medullary thyroid carcinoma syndrome were studied; one had multiple mucosal neuromas and ganglioneuromatosis, the other had bilateral pheochromocytomas. Both biological and immunological assays of a mucosal neuroma revealed high concentrations of calcitonin (CT) in the tissue (170 and 130 MRC U/g by the two assay methods, respectively). There was no microscopic evidence for contamination of the neuroma by medullary carcinoma. The two pheochromocytomas from the other case contained 6.2 and 13 MRC U of CT/g by immunoassay and measurable amounts by biological assay although, in the bioassay, there was partial inhibition of the hypocalcemic response of the assay rats by the high concentrations of epinephrine (840–960 ng/mg) and norepinephrine (215–480 ng/mg) in the unfractionated extracts. This interference was eliminated by separation of CT from catecholamines by gel nitration. No metastatic medullary carcinoma was found in the pheochromocytomas. In the patient with bilateral pheochromocytomas, metastatic (liver) medullary thyroid carcinoma contained levels of epinephrine (30 ng/mg) and norepinephrine (11 ng/mg) which were high but only about 1/30th those measured in the benign pheochromocytomas. We conclude that pheochromocytomas and mucosal neuromas can, on occasion, produce CT, and furthermore that some medullary thyroid carcinomas can probably produce epinephrine and norepinephrine in addition to CT.