pathology_of_human_tumor:sections demonstrate a cellular round blue cell neoplasm composed of sheets of undifferentiated cells with minimal cytoplasm and hyperchromatic nuclei. the cells are often elongated and carrot-shaped. myoblastic differentiation as evident by the presence of elongated strap cells with focal cross-striations present in a significant portion of the tumor (at least 30%). these cells stain for desmin. microvascular proliferation and frequent mitotic figures are seen. normal cerebellar tissue is present in part e with an infiltrating interface with the tumor.