What Does Diagnosis Ewings Sarcoma Suggest?

there is 1 small tumor in my back.. i did operation by well known doctor in my city.. the tumor was sent for reports in the lab. the reports came and in report they wrote in diagnosis are as follows- " Light Microscopy And IHC Favour Diagnosis of primitive neuro ectodermal tumour/ ewing's sarcoma. " what does this means please help me..