Pathologic Fracture of the Femur in Brown Tumor Induced in Parathyroid Carcinoma: A Case Report.

Brown tumor refers to a change of skeletones that develops as a complication of hyperparathyroidism. As osteoclast is activated to stimulate reabsorption and fibrosis of bone, it causes a cystic change of the bone. Parathyroid carcinoma is being reported as a tumor that induces primary hyperparathyroidism. It causes excessive secretion of the parathyroid hormone and increases the blood parathyroid hormone and calcium. Bone deformation due to brown tumor is known to be naturally recovered through the treatment for hyperparathyroidism. However, there is no clearly defined treatment for lesions that can induce pathological fractures developing in lower extremities. We experienced a case where brown tumor developed in the proximal femur of a 57-year-old female patient due to parathyroid carcinoma. In this case, spontaneous fracture occurred without any trauma, and it was cured by performing intramedullary nailing fixation and parathyroidectomy. We report the treatment results along with a literature review.