Solitary osteochondroma arising from the thoracic facet joint--case report.

A 15-year-old male presented with pain in the back and paresthesia and weakness of both lower limbs progressing for 6 months. Magnetic resonance imaging revealed a mass lesion occupying the spinal canal at the T-10 to T-11 levels, which had severely compressed the cord. At surgery, a firm and cartilaginous tumor originating from the facet joint was radically excised. The patient showed rapid neurological recovery following the surgery. Histological examination revealed that the lesion was osteochondroma. Such lesions are extremely rare in the lower thoracic spine and osteochondroma arising from the thoracic facet joint is unique.