Ewing's sarcoma of the head and neck: differential diagnosis, treatment and outcomes.

Abstract

Purpose of review: Ewing's sarcoma is a small round-cell tumour typically arising in the bones, and only rarely affecting soft tissues. These are rarely seen in the head and neck comprising 1-9% of all cases, making management of these tumours a challenge. This review aims to review the current literature to update the current diagnostic and treatment options in head and neck Ewing's sarcoma.

Recent findings: The tumour is characterized in most cases by recurrent balanced translocations between the EWSR1 gene on chromosome 22 and genes belonging to the ETS family of transcription factors. Its main driver is the reciprocal translocation between the EWSR1 and FLI1 genes (EWSR1:FLI1). Molecular techniques for the detection of FET/ETS fusions are widely used to confirm the diagnosis. Newer entities like adamantinoma-like Ewing sarcoma have been recently described. The chemotherapy protocols also have changed following Euro Ewing 2012 study. Reclassification of margin status may help standardize treatment in these cases.

Summary: Head and neck Ewings sarcoma is an uncommon tumour, mainly affecting paediatric/adolescent male individuals. Histopathological diagnosis is often challenging and immunohistochemical markers and/or molecular tests are generally used. Several molecular techniques for the detection of FET/ETS fusions are widely used to confirm the diagnosis. Management of Ewing's consists of a multimodal treatment regimen, including surgical resection and/or local radiotherapy, as well as intensive multiagent chemotherapy. Increase in age and the presence of distant metastasis are associated with shorter survival times.