Background:

Carcinoma of the parathyroid gland (PC) described by De Quervain since 1909, it represents the least common neoplasm, with an incidence of 1,25/10,000,000 peoples. It has been reported approximately 1,000 cases of CP in world literature. There are two series in Mexico, one of eight patients and other with four cases. Because CP is functionally active, its early clinical behavior is similar to that of parathyroid benign neoplasms.

Clinical case:

A 66-year-old female with history of thighbone pain and spontaneous femoral fracture, osteolytic lesions, hypercalcemia, elevated levels of alkaline phosphatase and parathyroid hormone detected; the scintigraphy showed a functioning tumor located in upper mediastinum. By hemithyroidectomy in block, the tumor was resected. Histopathological study reported parathyroid carcinoma.

Discussion:

PC is the least common neoplasia, in patients with parathyroid hormone levels greater than 1,000 pg/ml and hypercalcemia upper of 14 mg/dl this disease should be suspected.