Aneurysmal bone cyst in thoracolumbar spine.

Aneurysmal bone cysts (ABC) are rare, benign primary bone tumors. Although benign, they can be locally aggressive resulting in erosion of bone and surrounding tissues over time. In later stages, depending on the clinical urgency, immunotherapy or surgical resection remain treatment options. This report illustrates a case of a 32-year-old female who presented with chronic worsening low back pain without neurological deficits. Radiological imaging revealed a large destructive mass arising from the thoracic spine invading into the central canal, causing critical central stenosis and cord compression. Histopathology revealed ABC. This case highlights the importance of including ABCs and other 'benign'/locally aggressive lesions in the differential of patients with insidious musculoskeletal complaints. This case also demonstrates that one can be neurologically asymptomatic despite having critical central canal stenosis and cord compression if the causative lesion is slow growing. Understanding this allows us to arrange for most appropriate management.