Brown tumor of the femur and pelvis, an unusual presentation in a patient with parathyroid carcinoma. A case report.

Resumen

Brown tumors result from excess osteoclast activity and consist of collections of osteoclasts intermixed with fibrous tissue and poorly mineralized woven bone. They are secondary to hyperparathyroidism (HPT). Their incidence is higher in primary than in secondary hyperparathyroidism. We report a 69 years-old male, admitted in a state of confusion, lethargy and bedridden, with a pathological fracture of the femur caused by a brown tumor. The laboratory examination revealed a hypercalcemia (8.85mEq/L), with high levels of ionized Ca (5.48mEq/L), serum alkaline phosphatases (416 U/L) and serum parathormone (120 pg/mL). Ultrasound examination of the neck showed a large parathyroid tumor, probably corresponding to a carcinoma. A primary HPT was diagnosed. The patient was hydrated and high doses of diuretics and bisphosphonates were administered. After correction of serum calcium and neurologic symptoms, the patient was operated, performing an extensive resection of the tumor. The pathology report confirmed the diagnosis of parathyroid carcinoma.