[Total thyroidectomy in C-cell hyperplasia of the thyroid gland]

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor of the thyroid parafollicular or C-cells. MTC accounts for approximately 3 to 5% of thyroid carcinomas. A characteristic feature of this tumor is production of calcitonin. Sporadic MTC accounts for 60-80% of all cases of the disease. The most common presentation of sporadic MTC is a solitary thyroid nodule, which occurs in 75 to 95% of patients. It typically occurs in the fifth or sixth decades, with slight female predominance.

A case of a 58-year old woman with elevated basal calcitonin levels (221 pg/ml) has been presented. Preoperative ultrasound of the thyroid gland and body (99m)Tc DMSA scintigraphy showed a diffuse goiter. Hyperparathyroidism and pheochromocytoma were not present. Total thyroidectomy was performed. Only C-cell hyperplasia was found.

Many patients with elevated basal serum calcitonin level ranging between 150 and 1000 pg/ml, have only C-cell hyperplasia, but a few have small MTCs. For persons in known kindreds with familial MTC, prospective screening, using serum calcitonin measurement, can identify those at risk for the disease before MTC is clinically evident. Due to the possibility that any patient with MTC may have multiple endocrine neoplasia type 2 (MEN-2), preoperative testing must also include measurement of serum calcium (to rule out hyperparathyroidism) and a test for pheochromocytoma. Total thyroidectomy is indicated in patients with high levels of calcitonin.