Nonfunctional parathyroid carcinoma.

Parathyroid carcinoma is a rare entity accounting for 0.5% to 5% of parathyroid neoplasia. Most of these malignancies present as functional hormone-producing masses with elevated serum levels of parathormone and calcium. These tumors may also be nonfunctional. Clinical detection of nonfunctioning parathyroid malignancies preoperatively is primarily based on symptoms of an expanding neck mass. This ominous complaint is typically accompanied with an advanced stage of the disease at initial diagnosis. Because there is a paucity of data in the literature regarding nonfunctioning parathyroid carcinoma, prognosis can not be readily assessed. In both functional and nonfunctional parathyroid carcinoma, early surgery has proven to be the only curative treatment approach whereas both chemotherapy and radiation therapy fail to produce systemic or regional benefit when used alone. Hence, parathyroid cancer should be considered in every patient evaluated for a neck mass regardless of the blood calcium and blood parathormone level.