Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 1 1 2016 01 20 7 10 EN Neda Naderi Department of Internal Medicine, Imam Khomeini Medical Center, Tehran University of Medical Sciences, Tehran, Iran Azam Alamdari Department of Internal Medicine, Imam Khomeini Medical Center, Tehran University of Medical Sciences, Tehran, Iran Maryam Edalatifard Department of Internal Medicine, Imam Khomeini Medical Center, Tehran University of Medical Sciences, Tehran, Iran Seyyed Farshad Allameh Department of Internal Medicine, Imam Khomeini Medical Center, Tehran University of Medical Sciences, Tehran, Iran Department of Internal Medicine, Imam Khomeini Medical Center, Tehran University of Medical Sciences, Tehran, Iran 2016 01 20 2016 01 20 Primary hyperparathyroidism usually presents with renal, gastrointestinal, mental and skeletal signs and symptoms. Brown tumor is a benign lesion that arises as a direct result of parathyroid hormone on bone tissue in some patients with hyperparathyroidism. Multiple brown tumors may simulate a malignant neoplasm and it is a real challenge for the clinicians in the differential diagnoses. Here, we present a 68-year-old man with multiple lytic lesions in pelvis bones, highly suspicious for metastatic malignancy that finally we found that the patient had primary hyperparathyroidism. https://crcp.tums.ac.ir/index.php/crcp/article/view/23 https://crcp.tums.ac.ir/index.php/crcp/article/download/23/3