[Diagnosis of adrenal medullary diseases in patients with sporadic or hereditary medullary thyroid carcinoma. A report of 37 cases with 8-year follow-up study].

Thirty-seven patients with medullary thyroid carcinoma were investigated to determine the status of adrenal medulla by computed tomography and 131I-metaiodobenzylguanidine (131I-MIBG) scintigraphy as well as measurements of urinary catecholamine excretion. Patients were followed up for 8 years in maximum. Fifteen patients belonged to multiple endocrine neoplasia type 2 including patients with incomplete phenotype. Computed tomography demonstrated adrenal tumors or enlargement in all 6 patients with urinary epinephrine (E) more than 30 micrograms/day, 4 of them were confirmed to have pheochromocytoma or adrenal medullary hyperplasia by surgery. In 2 patients with E less than 30 micrograms/day and epinephrine to norepinephrine (E/N) ratio more than 0.3 suggesting adrenal medullary hyperfunction, computed tomography revealed small adrenal tumors. Three of the remaining 7 patients with E less than 30 micrograms/day and E/N ratio less than 0.3 had equivocal enlargement of unilateral gland on computed tomography. 131I-MIBG scintigraphy demonstrated tracer uptake in adrenal glands with tumor more than 1cm in diameter. One of 2 adrenal glands with medullary hyperplasia showed a faint adrenal image on the scintiscan, but the other showed no tracer uptake. Pheochromocytoma became manifest in 4 patients during the follow-up period, 4, 13, 14 and 34 years after thyroid surgery. None of 22 patients with sporadic medullary thyroid carcinoma showed adrenal abnormalities on the examinations mentioned above.