[Immunomorphological method in the diagnosis of rhabdomyosarcomas]

Eight rhabdomyosarcomas were examined by indirect Coons method using rabbit antisera to myosin of human striated and smooth muscles. Positive immunofluorescence with the antiserum to striated muscle myosin was observed in 6 out of 8 tumors. In the preparations treated with the antiserum to smooth muscle myosin, fluorescence of smooth muscles of the blood vessels was observed. Immunofluorescence was absent in 1 embryonal and 1 pleomorphic rhabdomyosarcomas. The tumors with positive fluorescence included 2 embryonal, 1 alveolar rhabdomyosarcomas, 1 metastasis of testicular rhabdomyosarcoma into the lymph nodes, 1 rhabdomyosarcoma of undifferentiated type, and 1 rhabdomyosarcoma with signs of therapeutic pathomorphosis. The high resolving capacity of the method allows its use for specification ppf histological diagnosis of tumors with different levels of cytodifferentiation.