Atypical presentation of L3 vertebral body osteochondroma mimicking cauda equina syndrome: a case report.

Background: Osteochondromas are common benign bone tumors, but spinal involvement is rare (<4%), with vertebral body origin being exceptionally uncommon. Neurological symptoms are typically mild and unilateral, making presentations mimicking incomplete cauda equina syndrome (CES) exceedingly rare. Case presentation: A 58-year-old Indian male presented with progressive lower back pain, followed by bilateral lower limb weakness and saddle anesthesia. There was no history of trauma, radiation, malignancy, or inflammatory disease. Neurological examination revealed flaccid paraplegia, areflexia, and decreased sensation below L3. Magnetic resonance imaging showed a hyperintense lytic lesion in the L3 vertebral body compressing the thecal sac; computed tomography confirmed continuity with the cortical and medullary bone, suggestive of spinal osteochondroma. The patient underwent L3 laminectomy with pedicle screw fixation at L2 and L4. Histopathology confirmed benign osteochondroma. At 6 months, the patient showed substantial motor recovery with no recurrence. Case discussion: Spinal osteochondromas usually arise from posterior elements. Vertebral body involvement is extremely rare. This case is notable for its late presentation in an elderly patient without known risk factors. The incomplete CES presentation was likely due to selective nerve root compression and possible ischemia. Imaging was critical in diagnosis, and surgical excision remains the treatment of choice. Literature supports low recurrence after complete resection, though long-term outcomes remain underreported. Conclusion: This case highlights a rare vertebral body osteochondroma mimicking incomplete CES. Early imaging and prompt surgical management are essential to avoid permanent neurological deficits. Further research is needed to understand pathogenesis in older adults without typical risk factors.