Update on the management of parathyroid tumors

Abstract

Parathyroid tumors are virtually always benign with an estimated incidence of parathyroid carcinoma causing hyperparathyroidism in only .017% of cases. Virtually all parathyroid neoplasms, including the rare parathyroid carcinoma, are functional and discussion of the management of parathyroid tumors is tantamount to the discussion of primary hyperparathyroidism. The biochemical diagnostic criteria with rare exception is definitive, and the key issue with this functional benign endocrine neoplasm is when to recommend operation and how to ensure optimal results in this curable disease. Patients symptomatic with nephrolithiasis, significant osteoporosis, bone pain, and in some cases constitutional symptoms should undergo a surgical therapy. Also, patients with markedly abnormal laboratory values including a calcium 12.0 mg/dL, or 24-hr urinary calcium >400 mg/day should be treated surgically. The sestamibi nuclear medicine scan has become the best tool available for imaging of abnormal parathyroid glands. This study is positive between 60% and 90% of initial operations and in between 40% and 70% of re-operations. For multi-gland parathyroid disease or hyperplasia, the sensitivity of this test is decreased. Understanding of the ectopic locations of parathyroid adenoma is of utmost importance in the conduct of the parathyroidectomy. For the rare patients with parathyroid carcinoma, aggressive surgical resection with en bloc removal of any adjacent invading structures is the best chance for cure leading to 10-year survival rates of 49%.