Two novel translocations, t(2;4)(q35;q31) and t(X;12)(q22;q24), as the only karyotypic abnormalities in a malignant peripheral nerve sheath tumor of the skull base.

Malignant peripheral nerve sheath tumor (MPNST) is a rare neoplasm that originates from Schwann cells and comprises 5%-10% of soft tissue sarcomas. Cytogenetic analysis of this tumor has shown a highly complex karyotype, and no single chromosomal aberration has been reported to date. We combined spectral karyotyping analysis and G-banding for cytogenetic characterization of this unique tumor, which originated in the anterior skull base. We report the simultaneous occurrence of a t(2;4)(q35;q31) and a t(X;12)(q22;q24) as the only chromosomal abnormalities in this tumor. To the best of our knowledge, apparently balanced translocations have not been identified previously in MPNST.