Extra-osseous Ewing's sarcoma of sciatic nerve masquerading as an infected hemangioma: A rare case report

Extraskeletal Ewing sarcoma of the sciatic nerve

Extraskeletal Ewing sarcoma (EES) is a rare tumor diagnosed in children or young adults and is even more unusual in individuals over 30 years of age. Due to its rare occurrence and low index of suspicion, this tumor can pose diagnostic and therapeutic challenges. We present a case of a 60-year-old male with EES of the sciatic nerve, an unexpected entity given the patient's age, tumor type, and tumor location. This can mimic a nerve sheath tumor on imaging.

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.

Extraskeletal Ewing's Sarcoma Arising from the Sciatic Nerve: A Diagnostic Challenge

Ewing's sarcoma is a common bone tumour of childhood but is a rare occurrence in individuals over 20 years of age. Few cases are reported as originating from peripheral nerves. We present an unusual case of extraosseous Ewing's sarcoma originating from the sciatic nerve in a 66-year-old patient which had the clinical hallmarks of a benign nerve sheath tumour. Following discussion at a multidisciplinary meeting, excision biopsy of the suspected benign nerve sheath tumour was planned. At operation, the mass had malignant features. Histology confirmed the presence of Ewing's sarcoma. Due to the morbidity of nerve resection, radiotherapy and chemotherapy were commenced. Ewing's sarcoma is known to mimic benign pathologies. In this case there were subtle signs of a malignant process in the form of unremitting pain. It is vital to keep in mind the less common tumours that can affect the peripheral nervous system in such cases.