LAUSR

Background: Brown tumor (Osteoclastoma) is a rare benign, focal, lytic bone lesion most commonly attributed to a parathyroid adenoma; it occurs in approximately 5% of patients with primary hyperparathyroidism, and 13% of patients with secondary hyperparathyroidism. Most tumors are located in the mandible, pelvis, ribs, and large bones; only rarely is it found in the axial spine. Case Description: A 37-year-old male with primary hyperparathyroidism presented with an MR-documented T4 and T5 brown tumor (Osteitis Fibrosa Cystica) resulting in an acute paraparesis. The patient successfully underwent excisional biopsy of an expansile, enhancing, bony destructive lesion at the T4-5 level. Subsequently, he required subtotal excision of a left upper parathyroid tumor. Conclusion: Patient with primary hyperparathyroidism may acutely present with paraparesis attributed to brown tumors of the spine warranting emergent operative decompression.