ABSTRACT
Parathyroid carcinoma (PC) is a rare, malignant neoplasm of the parathyroid glands that causes parathyroid hormone-dependent hypercalcemia. The distinction between primary hyperparathyroidism due to the common parathyroid adenoma and the rare parathyroid carcinoma is rarely made on clinical grounds. Parathyroid carcinoma may be identified during surgery, but the diagnosis is made only after careful histopathological examination of the resected specimen or at recurrence months or years following resection. A diagnosis of parathyroid carcinoma is made with certainty by the demonstration of direct invasion of adjacent tissues, synchronous or metachronous cervical lymph node, or distant metastases.
