Abstract
Pheochromocytoma occurs in MEN2. Lethal complications may develop if the existence of pheochromocytoma is unknown, when MEN2 patients undergo surgical procedures. The surgical treatment of medullary thyroid carcinoma precedes that of pheochromocytoma in MEN2 patients, and it is necessary to check for the presence of pheochromocytoma before thyroidectomy. The probability of pheochromocytoma was reported as 50% in MEN2, but this is based on old data before the advent of gene diagnosis and early thyroidectomy for medullary thyroid carcinoma. If medullary thyroid carcinoma is treated early, the life expectancy might increase, consequently, the probability of pheochromocytoma may rise. There is a report in which pheochromocytoma was responsible for 2/3 of the causes of death in patients with MEN2 who developed pheochromocytoma. During the follow-up of MEN2 patients after total thyroidectomy for medullary thyroid carcinoma, there exists much controversy in the treatment of pheochromocytoma: when pheochromocytoma should be treated surgically, what should the surgical procedure be, total adrenalectomy or partial adrenalectomy, etc.
