Extra-Osseous Ewing Sarcoma of Sciatic Nerve Masquerading as Benign Nerve Sheath Tumor and Presented as Lumbar Radiculopathy: Case Report and Review of Literature.

BACKGROUND

Extraosseous Ewing sarcoma (EES) arising from peripheral nerves is extremely rare with only 11 cases mentioned in the literature. It poses a diagnostic challenge to the clinicians due to its nonspecific presentation and rare occurrence.

CASE DESCRIPTION: A 56-year-old woman came with a history of low back pain and intractable right leg pain. Physical examination revealed the normal motor power of both lower limbs with decreased sensation along the lateral aspect of the foot with decreased ankle reflex. There was no improvement with conservative management. It was a diagnostic challenge due to its presentation like a lumbar radiculopathy, which was further endorsed by magnetic resonance imaging findings of foraminal stenosis. Due to red flags such as unrelenting pain at rest and history of thyroid tumor, we proceeded with magnetic resonance imaging of the hip, which was suggestive of right sciatic nerve sheath tumor. Excisional biopsy was confirmed as EES, and the patient was subsequently started on chemoradiotherapy.

CONCLUSION

A high index of suspicion is required for early diagnosis of EES. It can present as lumbar radiculopathy and mimic benign nerve sheath tumor on imaging. These sarcomas must be managed with a multidisciplinary approach.