Large group of small-round-cell tumours of soft tissues and bone represents a complex diagnostic problem for the pathologists. Neuronal nature of many tumours from this group is proven by means of new methods--immunophenotypic analysis, tissue culture, cytogenetics. Peripheral neuroepithelioma, Ewing tumour, primitive neuroectodermal tumour (PNET), Askin tumour belong to these neoplasms