Secondary hyperparathyroidism and nonmedullary thyroid cancer.

Nonmedullary thyroid carcinoma is known to occur in association with primary hyperparathyroidism. A combination of secondary, uremic, hyperparathyroidism and non-medullary thyroid carcinoma is rare and was hitherto reported in only 12 cases. We report another three patients with this parathyroid/thyroid disease combination, suggesting that it may represent not merely a coincidence. A number of factors active in secondary hyperparathyroidism may play a role in the induction and/or promotion of the thyroid cancer. These include parathyroid endocrinopathy, goiterogenic effect of prolonged hypercalcemia, and uremia. During surgery on the parathyroid glands, associated thyroid lesions demand special considerations.