Spinal Epidural Extraskeletal Ewing Sarcoma: A Rare Case With Bone Marrow Involvement

Extraskeletal Ewing sarcoma (EES) is a rare, malignant small round-cell tumor, and involvement of the spinal epidural space is unusual.Here, we report a case of spinal epidural EES in a 46-year-old man who presented with back pain.Magnetic resonance imaging revealed a dumbbell-shaped right paravertebral mass extending through the ipsilateral neural foramen, with focal bone marrow infiltration.After surgical resection and adjuvant chemoradiotherapy, progressive bone marrow involvement and vertebral metastasis were observed on follow-up imaging.This case highlights the diagnostic challenges of epidural EES and underscores the importance of recognizing bone marrow involvement, which is rare in EES.