Intra-neural Ewing's sarcoma of the upper limb mimicking a peripheral nerve tumour. A report of 2 cases

Ewing's sarcoma is a malignant round cell tumour of bone commonly affecting children and young adults. Intra-neural Ewings is very rare form of extraosseous Ewing's sarcoma (EES), posing diagnostic and therapeutic challenges. We report two cases of intra-neural EES presenting with elbow pain and swelling, mimicking an upper limb peripheral nerve sheath tumour. Following a CT guided biopsy to confirm diagnosis, the patients were treated with a combination of surgical resection, chemotherapy and radiotherapy. These cases highlight the potential diagnostic challenges as their presentation can be misleading due to the non-specificity of symptoms. These are highly aggressive tumours with the propensity to metastasize. We review importance of collective radiological and immunohistochemical analysis followed by early, aggressive multimodal treatment within a multidisciplinary setting. This provides the best prognosis in the context of upper limb peripheral nerve tumours.