Primary Hyperparathyroidism Presenting as Aneurysmal Bone Cyst of Tibia and Giant Cell Lesion of Mandible.

Abstract

Primary hyperparathyroidism (PHPT) is characterized by autonomous overproduction of parathyroid hormone (PTH) along with normal or high-normal serum calcium. It affects 1% of population and 85% cases are the result of a single parathyroid adenoma. Over-secretion of PTH may result in bone pains, progressive bone loss, pathologic fractures, bone tumors, renal calculi and proximal myopathy.1,2 Several bone lesions, including metabolic disorders, may contain osteoclast rich giant cells. These lesions including giant cell tumors, aneurysmal bone cysts, and brown tumors of hyperparathyroidism have structural similarities. The most important functional similarity is their capability of bone resorption.1-3 In patients presenting with bone pains, weight loss, bone swellings or pathologic fractures, possibility of metastatic bone disease is often considered in the differential. Here, we report the case of a patient who was referred for skeletal scintigraphy, with clinical suspicion of metastatic bone disease.