Medulloblastoma with striated muscle fibers

✓ A case is reported in which a medulloblastoma showed evidence of striated muscle fibers. Fifteen additional cases of primary central nervous system (CNS) tumor containing muscle fibers (excluding teratomas) are reviewed. These tumors appear to be of mesenchymal, rather than teratoid, origin, and to be related to embryonal sarcomas (mesenchymomas) in other parts of the body. It is postulated that the presence of such fibers in malignant gliomas may be due to rhabdomyoblast-inducing action of mesenchyme, analogous to the fibroblastic stimulation observed in desmoplastic medulloblastomas, and the massive stimulation of perivascular tissue often associated with undifferentiated astrocytomas.