Ultrasonic localization and cytologic identification of parathyroid tumors

Ultrasonic examination of the parathyroid glands was performed in 55 consecutive patients with subsequent surgically verified hyperparathyroidism. Ultrasound located 26 of 37 parathyroid adenomas in the neck. Eleven of 48 hyperplastic glands in the neck were visualized by ultrasound in 16 patients with primary or uremic hyperplasia. A parathyroid adenoma was revealed in all 3 patients with hypercalcemic crisis and in all 5 patients with an adenoma and a previously unsuccessful exploration of the neck. Two of 3 glands were visualized by ultrasound prior to secondary explorations in 3 patients with primary hyperplasia associated with the multiple endocrine neoplasia syndrome type I. Undetected parathyroid glands were generally small and located in regions of the neck difficult to detect by ultrasound. It was often difficult to unequivocally establish that identified lesions represented a parathyroid gland. Nodules and cysts of the thyroid and lymph nodes were misinterpreted for parathyroid lesions. Ultrasonically guided fine-needle biopsies were obtained from 8 parathyroid lesions, 7 thyroid tumors, and 2 lymph nodes. By cytologic examination these tissues could be discriminated after a differential staining of the aspirates.