Primary cutaneous Ewing sarcoma/primitive neuroectodermal tumour: a clinicopathological analysis of seven cases highlighting diagnostic pitfalls and the role of FISH testing in diagnosis

Abstract

Although rare, primary cutaneous ES/PNET should be considered in the differential diagnosis of cutaneous "small blue cell tumours". Immunostaining for FLI-1 and molecular testing for evidence of an EWS rearrangement are useful ancillary investigations to confirm the diagnosis. The prognosis of primary cutaneous ES/PNET appears to be more favourable than extracutaneous ES/PNET.