Intrathyroidal parathyroid.

Fifty-eight human fetal thyroid glands obtained at autopsy were systematically studied for the presence of intrathyroidal parathyroid tissue. The latter was found in 13 thyroid lobes from 12 fetuses. It was located in a subcapsular position in 9 of 58 cases and lying deep in thyroid tissue in 4 of 58. Our findings suggest that intrathyroidal parathyroid tissue is not such a rare finding and should always be considered especially for the clinical and surgical management of patients with primary hyperparathyroidism due to parathyroid hyperplasia.