Brown Tumor of Shaft of Humerus As First Presentation of Primary Hyperparathyroidism Caused By Parathyroid Hyperplasia

Excessive parathyroid hormone secretion is one of the important causes of bone resorption. Under the influence of excessive parathyroid hormone bones undergo cystic and fibrotic changes. These characterstic changes are called brown tumor. Brown tumors are rare manifestation of hyperparathyroidism and usually occurs in less than 2% patients of hyperparathyroidism. The skeletal manifestations of hyperparathyroidism are usually found in phalanges, metacarpals, facial bones, pelvic bones, ribs and sometimes femur and tibia. The incidence of these changes in humerus is uncommon. We report here a case of brown tumor involving shaft of humerus. Patient presented to us after a trivial trauma. On X-ray she had lytic lesion involving shaft of humerus. She was further investigated and was found to be having hyperparathyroidism secondary to diffuse parathyroid hyperplasia.