An unusual presentation of primary hyperparathyroidism: severe hypercalcemia and multiple brown tumors.

Primary hyperparathyroidism is common, particularly in postmenopausal women. Since the introduction of routine automated serum calcium assays and the development of assays for intact 1-84 parathyroid hormone, the diagnosis is usually made fortuitously in asymptomatic patients or during evaluation for osteoporosis. As a result, many physicians have no experience with the clinical manifestations. Here, we describe the case of a 70-year-old man with bone pain, multiple brown tumors, and severe hypercalcemia (4 mmol/L). The diagnostic pitfalls raised by these symptoms are illustrated.