Primary Ewing's sarcoma of the C2 vertebra with progressive quadriparesis: Report of a rare case and review of the literature.

Background: Ewing's sarcoma is a malignant primitive neuroectodermal tumor (PNET) of childhood and adolescence. Primary Ewing's sarcoma of the spine is uncommon, and even more rarely involves the C2 vertebra.

Case Description: A 14-year-old patient was admitted with a history of chronic neck pain, which exacerbated after playing contact sports 3 weeks before presentation. On initial examination, he had pain radiating into the left upper extremity plus spasticity in all the four limbs. The cervical X-rays revealed a mixed sclerotic-lytic lesion involving the C2 vertebral body. The CT bony and soft-tissue windows documented predominant left-sided tumor invasion of the posterior elements, pedicles, and body of C2 along with extension into the spinal canal resulting in severe cord compression with peritumoral soft-tissue edema. The angiogram revealed a patent left vertebral artery entirely surrounded/encased by tumor. The PET-CT scan demonstrated no other spinal or systemic lesions. Due to his rapid neurological deterioration, the patient underwent an emergent biopsy of the tumor with posterior decompression and occipitocervical stabilization. The biopsy demonstrated a PNET (e.g., positive CD 99 MIC2 marker for Ewing's sarcoma). Following subsequent chemotherapy and radiation, the patient rapidly improved over a period of 3 months.

Conclusion: Primary Ewing's sarcoma involving the C2 vertebra is exceedingly rare and warrants surgical decompression with pathological confirmation to provide additional multi-modal/multi-disciplinary adjunctive radiation/chemotherapy.