Giant Cell Tumor in the Thoracolumbar Junction: A Case Report.

A giant cell tumor (GCT) of the spine is an uncommon benign bone neoplasm that can behave aggressively and cause neurological compromise. Its rarity and location within load-bearing, neuro-critical anatomy make diagnosis and management particularly complex. A 34-year-old woman presented with progressive thoracolumbar pain, kyphotic deformity, and incomplete spinal cord injury leading to transient paraplegia. Radiographs showed 90% collapse of the L1 vertebral body with about 45° regional kyphosis. Magnetic resonance imaging revealed an expansile lytic lesion at L1 with paravertebral extension and severe canal compromise.  Definitive management was achieved through a posterior-only approach using a Schwab type five osteotomy, mesh-cage reconstruction with autograft, and T12-L4 instrumentation. Postoperatively, the patient showed rapid sensory recovery below T11 and preserved motor function, regaining ambulation within 24 hours. Follow-up imaging confirmed correction of deformity and construct stability. Histopathology demonstrated multinucleated giant cells in a mononuclear stromal background, confirming GCT. Locoregional recurrence was identified eight months postoperatively. This case highlights the value of prompt recognition and meticulous surgical planning in spinal GCT. Early intervention with complete resection and stabilization can restore alignment, prevent permanent neurological deficits, and achieve durable local control. Multidisciplinary management is crucial for optimizing outcomes in these rare but challenging lesions.