Secondary Hyperparathyroidism Presenting as a Brown Tumor: A Case Report and Review of the Literature

Severe secondary hyperparathyroidism in advanced stages of chronic kidney disease (CKD) is associated with CKD-related mineral and bone disease (CKD-MBD). A 70-year-old woman was admitted at the Hospital for generalized bone pain and peripheral edema. Initial laboratory tests revealed normocytic anemia and severe renal dysfunction, and further tests evidenced severe secondary hyperparathyroidism. Full-body computerized tomography showed an osteolytic lesion in the right iliac wing. The iliac bone lesion was biopsied and histological examination was consistent with the diagnosis of a brown tumor of hyperparathyroidism. Brown tumors are a rare variant of osteitis fibrosa cystica that results from sustained high levels of parathyroid hormone in CKD. This case sheds light on rare complications that are experienced today in CKD. The clinical and biochemical setting, as well as the clinical suspicion, are essential to the diagnosis.