Nonfunctioning parathyroid carcinoma.

Parathyroid carcinoma is a rare clinical entity accounting for only 4 per cent of all cases of parathyroid neoplasia. Nonfunctioning parathyroid carcinoma is even rarer. Previously, virtually all patients with these lesions were treated for a nonspecific neck mass. However, in the present case, a preoperative diagnosis of nonfunctioning parathyroid carcinoma was made based on the technetium pertechnetate/thallium 201 subtraction scan. The authors report on the 14th case of nonfunctioning parathyroid carcinoma, a review of the literature, and guidelines for the preoperative and operative evaluation of neck masses suspected to be parathyroid carcinoma.