Juvenile xanthogranuloma of nerve root origin.

A case of juvenile xanthogranuloma arising from the first sacral nerve root is reported together with a review of the literature. The patient presented with symptoms of low back pain and sciatica, and with S1 nerve root tensions signs. Computed tomography and magnetic resonance imaging revealed a mass arising from the right S1 nerve root. The tumour was resected, and the morphological and immunocytochemical appearances of the lesion confirmed the diagnosis of juvenile xanthogranuloma. Soft tissue juvenile xanthogranulomas have been described but are extremely rare. However, we believe this is the first reported case of such a tumour affecting a spinal nerve root.