In addition to the standard histopathological examination, immunohistochemical profile: SMA + Vimentyna + Desmina-, S100-, Ki67 + 10% plays an important role in LMS diagnostics; it allows us to differentiate tumors with similar histopathological image, that is, rhabdomyosarcoma, fibrosacoma, angiosarcoma, and the others. The gene discussed is MKI67; the disease is rhabdomyosarcoma.