Extraosseous Ewing′s sarcoma / primitive neuroectodermal tumor of the sacral nerve plexus

Abstract

AbstractWe report an unusual case of Ewing′s sarcoma / primitive neuroectodermal tumor (PNET) of the sacral nerve plexus in a 9-year-old boy who presented with a soft tissue swelling and severe piercing pain in the lower back region. MRI of the lumbosacral spine showed a lobulated soft tissue mass with clubbed finger-like projections along the path of the sacral nerves, which had caused widening of the spinal canal and the sacral foramina (S2-S4 level). There was presacral extension and posterior scalloping of the sacral vertebrae. Histopathology of the lesion confirmed Ewing′s sarcoma / PNET of the sacral spinal nerve plexus. The patient responded favorably to chemotherapy and radiotherapy, showing clinical and radiological improvement.