A malignant triton tumor with an unbalanced translocation (1;13)(q10;q10) and an isochromosome (8)(q10) as the sole karyotypic abnormalities.

The karyotype of a malignant nerve sheath tumor with rhabdomyosarcomatous differentiation (malignant triton tumor) of a 58-year-old woman is reported. The tumor revealed an isochromosome for the long arm of chromosome 8 and an unbalanced translocation (1;13)(q10;q10) leading to a gain of the long arm of chromosome 1 as the sole karyotypic abnormalities.