A Case of Primary Hyperparathyroidism Associated with Brown Tumor of the Right Patella

Abstract

Brown tumors are rare focal giant-cell lesions that arise as a direct result of the action of the parathyroid hormone (PTH) on bone tissue in patients with hyperparathyroidism. A 43-year-old woman was referred to the Department of Orthopedic Surgery at Hyogo Cancer Center with a complaint of swelling and pain in her right patella. Multiple cystic lesions were found in this area, and she underwent curettage of the bone lesions. Pathological findings showed a giant cell-like tumor. Postoperative examinations revealed that the patient had a very high serum calcium level, a high PTH level, and a tumor in the left lower portion of the thyroid gland. The neck tumor was examined at the Department of Head and Neck Surgery. The findings suggested that the patient had primary hyperparathyroidism with a brown tumor. We performed total thyroidectomy and parathyroidectomy. Pathological findings indicated papillary carcinoma and parathyroid adenoma. In this case, brown tumor was diagnosed on the basis of the clinical features, blood biochemical determinations, and pathological findings. A diagnosis of brown tumor should be considered when a patient presents with hypercalcemia and multiple bone tumors due to primary hyperparathyroidism.