Unusual presentation of primary hyperparathyroidism: report of three cases

Background Primary hyperparathyroidism is an endocrinopathic condition characterized by hypersecretion of parathyroid hormone. Excess parathyroid hormone results in an altered state of osseous metabolism involving bone resorption and tissue change known as osteitis fibrosa cystica, which is the end stage of primary hyperparathyroidism. Osteitis fibrosa cystica is associated with the development of brown tumors, which are rare because hyperparathyroidism is now usually diagnosed and treated before symptoms develop. Brown tumors are rarely the first symptom of hyperparathyroidism and can occasionally be mistaken for malignancy.