Hyperparathyroidism Mimicking Metastatic Bone Disease: A Case Report and Review of Literature.

Multiple osteolytic lesions are usually associated with metastatic involvement of the bone; however, metabolic bone diseases should also be included in the differential diagnosis. In this study, we describe a case of primary hyperparathyroidism (PHPT) with multiple osteolytic lesions that was diagnosed initially as having metastatic bone involvement. The laboratory results showed hypercalcemia and raised alkaline phosphatase along with fibrosis in the bone marrow biopsy with no increase in tumor markers and normal serum protein electrophoresis. The parathyroid hormone levels were high, which pointed toward a diagnosis of PHPT. Sestamibi scan revealed uptake at the level of the left inferior pole of the thyroid gland, which was suggestive of parathyroid adenoma. The possibility of hyperparathyroidism should be kept in mind when a patient presents with multiple osteolytic lesions and hypercalcemia.