[Studies on the submicroscopic structure of botryoid (rhabdomyo)-sarcomas of the nasopharynx (author's transl)].

Embryonal rhabdomyosarcomas and their botryoid variant are typical soft tissue sarcomas of infancy and childhood. Generally, the tumor cells are thought to be comparable with embryonal rhabdomyoblasts. Nevertheless, many authors do not require the cross-striation of the tumor cell cytoplasm as cytological marker for the diagnosis "rhabdomyosarcoma". In our study we examined the cytology of tissue samples of 4 botryoid sarcomas of nasopharynx with the electron microscope. A varying cytological picture was found. Besides undifferentiated tumor cells constituting the main part of the growths cellular elements with resemblance to fibroblasts, smooth and striated muscle cells, histiocytic cells and lipoblasts were observed. Furthermore, a vasoformative potency of the tumor tissue was occasionally seen. The conclusion is drawn from our results that, replacing the term embryonal rhabdomyosarcoma, such tumors should better be designated as embryonal sarcomas. We think it probable that the present concept of embryonal rhabdomyosarcomas must be revised.