[Three cases of primary hyperparathyroidism associated with nonmedullary thyroid neoplasm].

Among 18 surgical patients with primary hyperparathyroidism at this institution, 3 patients (16.7%) were found to have associated nonmedullary thyroid neoplasms. Histological examination of the parathyroid tumors revealed two to be parathyroid adenomas and the other to be parathyroid carcinoma. Histology of the thyroid neoplasms were papillary carcinoma, follicular carcinoma and follicular adenoma, respectively. Therefore, in the diagnosis of primary hyperparathyroidism, it is necessary to take into consideration association with not only medullary thyroid carcinoma, but nonmedullary thyroid neoplasms as well.