Malignant Triton tumor: a rare cause of sciatic pain and foot drop.

Malignant peripheral nerve sheath tumors (MPNST) are very rare and are frequently localized in the buttocks, thigh, arm, or paraspinal region; one variant is the malignant Triton tumor, with rhabdomyosarcomatous differentiation. The authors present a challenging differential diagnosis of a sciatic pain and foot drop in a woman with history of lumbar disk herniation, which was found to be caused by a Triton tumor of the sciatic nerve. She underwent surgical excision, followed by radiation and chemotherapy.