Osteolytic lesions caused by hyperparathyroidism mimicking multiple bone metastases

Multiple osteolytic lesions in elderly patients are usually metastatic bone tumors, while brown tumor is a rare disease featuring osteolytic lesions associated with hyperparathyroidism. In this report, we present the case of a 62-year-old male with hyperparathyroidism-induced multiple osteolytic lesions that mimicked multiple metastatic bone tumors. At initial presentation, the radiographic images were compatible with metastatic bone tumors; therefore, we performed a needle biopsy on the iliac lytic lesions, which revealed no evidence of malignancy. Furthermore, we performed an operation on the left radial pathological fracture and obtained sufficient sample for histological examination, which again showed no evidence of malignancy. Hence, while investigating for other diseases, we found a tumor in the left thyroid and high levels of intact-parathyroid hormone (PTH), which was a strong clue to the diagnosis of PHPT caused by a parathyroid adenoma. After the resection of the parathyroid adenoma, intact-PTH and calcium levels returned to normal. In conclusion, clinicians including orthopedic specialists should consider the possibility of brown tumors in case of aforementioned clinical features.