Brown tumor caused by primary hyperparathyroidism mimicking giant cell tumor of bone

Primary hyperparathyroidism (PHP) is an endocrine disorder characterized by the elevation of parathormone levels. Brown tumor, one of the complications of hyperparathyroidism, is the result of osteoclastic activity resulting in lesions, pathological fractures and pain in the skeletal system. Brown tumor can be confused with primary bone tumor, aneurysmal bone cyst or giant cell tumor of bone in both histopathological and radiological examinations. In this presentation, a 50-year-old female patient with a suspicion of metastatic bone tumor but diagnosed with primary hyperparathyroidism is presented. Brown tumors are benign lesions, but they can mimic malign bone diseases. Clinical, histopathologic and radiological findings should be evaluated together in differential diagnosis of the disease