LBODP017 Unusual Presentation Of Brown Tumors In Tertiary Hyperparathyroidism: A Case-based Review

Brown tumor (BT) is a rare non-neoplastic skeletal manifestation of untreated tertiary hyperparathyroidism (THPT) that is associated with renal osteodystrophy in patients with End-Stage Renal Disease (ESRD). Nearly half of patients with ESRD have Osteitis Fibrosa Cystica (OFC) of varying severity, which is the most common form of renal osteodystrophy. BT represents the extreme form of OFC. As a result of frequent monitoring of bone profile and the expansion of pharmacological therapy, the disease is increasingly being diagnosed in its early stages; however, some are still seen at an advanced stage. Depending on the tumor size, the management will range from a conservative approach with supportive parathyroidectomy to a comprehensive surgical removal. Here, we report a rare case of an extensive BT of the pelvis in a patient with ESRD and THPT who was also found to have coincidental papillary thyroid cancer following total thyroidectomy and parathyroidectomy with a postoperative complication of hungry bone syndrome. She then underwent prophylactic intramedullary nail fixation for an impending fracture in the right femur. This case report highlights the importance of considering BT as a differential diagnosis of lytic bone lesions and that measuring serum calcium, phosphorus, and parathyroid hormone as part of the initial evaluation is essential to identify the correct diagnosis. Multidisciplinary team approach with frequent follow-up is crucial to allow early diagnosis and prevent unnecessary surgical interventions. Presentation: No date and time listed