Endocrine Abstracts

Introduction: Brown tumor refers to the skeletal change that develops as one of the complications of hyperparathyroidism, in which cystic and fibrous changes occur in the bone. It occurs in approximately 10−20% of patients with primary hyperparathyroidism. Parathyroid cancer is a rare cause of primary hyperparathyroidism and accounts for approximately 1% of cases. In some cases, hyperparathyroidism may be asymptomatic until it becomes a pathological fracture and may be the first sign of a malignant tumor. Here, we report a case of parathyroid carcinoma presenting with bilateral femoral fracture because of its rarity.

Case: A 56-year-old male patient presented with pain and limitation of movement in both thighs after falling in the bathroom. It was learned that he had difficulty in walking and pain in the legs for 6 months in his history, and he did not have an additional disease or medication. X rays showed the fractures in both femurs and left olecranon and findings consistent with multiple (bilateral femur, tibia, fibula and right radius and ulna) Brown tumors were found in the bones. Blood investigations showed raised levels of serum calcium, with highly raised levels of serum parathyroid hormone (PTH). After neck ultrasonography and parathyroid scintigraphy, an appearance compatible with parathyroid adenoma was found in the inferior of the right thyroid lobe, and parathyroidectomy was performed, but postoperative PTH elevations continued. Thereupon, the patient was evaluated with neck tomography and parathyroid scintigraphy for the second time, and he was reoperated when another focus was detected in the upper mediastinum at the level of the angulus venosus in the isthmus inferior of the thyroid gland. The operative pathology resulted as parathyroid carcinoma. The patient who developed postoperative hungry bone syndrome was operated for bilateral femoral fracture after calcium normalization was achieved.

Conclusion: The main treatment for parathyroid carcinoma is surgery. In the presence of fracture, it is recommended to perform parathyroidectomy first and then orthopedic treatment. In the presence of osteolytic lesion and high serum calcium in patients presenting with pathological fracture, Brown tumor related to parathyroid carcinoma should be kept in mind in the differential diagnosis.

Keywords: Hyperparathyroidism, brown tumor, femur, pathological fracture.