Thyroid carcinoma in patients with secondary hyperparathyroidism.

There have been few reports of coexistence of secondary hyperparathyroidism (2 degrees HPT) and thyroid carcinoma. Eleven consecutive patients with 2 degrees HPT who underwent parathyroidectomy were analyzed. They consisted of six males and five females, whose age ranged from 34 to 55 years. None of the patients had a history of irradiation of the head or neck. Associated thyroid nodules were also present in seven patients (64%): four patients with benign nodules, and three patients with papillary carcinomas, and one with papillary carcinoma and two follicular adenomas. This incidence of thyroid carcinoma in the patient group with 2 degrees HPT (36%) was significantly higher than that of the autopsy group in the same geographical area (11%). The level of carboxyl-terminal parathyroid hormone in the patients with thyroid carcinoma was higher than that in the patients without thyroid carcinoma (P less than 0.05). The importance of searching for possible thyroid cancer in patients with 2 degrees HPT should be emphasized.