Endocrine Abstracts

Introduction: Brown tumors are rare focal giant-cell lesions that arise as a direct result of the effect of parathyroid hormone on bone tissue in some patients with hyperparathyroidism.

Case: A 55-year-old Saudi woman was admitted to King Abdulaziz University Hospital (Jeddah) with a complaint of anterior maxilla mass of one month duration. Her medical history was unremarkable.

Initial examination revealed a painful mass in the anterior maxilla. Surgery was not undertaken because routine laboratory investigations revealed hypercalcemia.

Initial laboratory tests performed on admission showed the following: alkaline phosphates, 143 IU/l (reference range, 50–136 IU/l); corrected serum calcium, 3.2 mmol/l (reference range, 2.12–2.52 mmol/l); and intact parathyroid hormone, 120 pmol/l (1.6–6.9 pmol/l). A provisional diagnosis was made for hypercalcemia due to hyperparathyroidism. Technetium thallium (99mTc-201Th) subtraction scintigraphy (Sestamibi scanning), which demonstrated a single, ectopic anterior mediastinal parathyroid adenoma. Magnetic resonance imaging (MRI) of the thorax showed a mediastinal parathyroid adenoma. Treatment was initiated by hydration with normal saline and intravenous biophoshante until normalization of the patient’s serum calcium level.

Initially the patient underwent extirpation of the mass and curettage of the bone under general anesthesia. Histological sections showed multiple giant cells consistent with Brown tumor of primary hyperparathyroidism. The patient was readmitted after 2 weeks, and she underwent mediastinal parathyroidectomy by median sternotomy. The lesion was histopathologically diagnosed as a parathyroid adenoma. The post-operative course was uneventful and the patient was discharged on the 6th post-operative day without complications. The results of postoperative laboratory tests were normal.

Conclusions: Owing to recent improvements in analytical techniques, the diagnosis of hyperparathyroidism usually occurs when the disease is in an asymptomatic phase, and the incidence of patients with advanced bone lesions is rare. The treatment of choice for bone lesions is parathyroidectomy.