Malignant peripheral nerve sheath tumor (MPNST) and MPNST-like entities defined by DNA methylation profile in pediatric and juvenile population

The diagnosis of Malignant peripheral nerve sheath tumors (MPNSTs) can be challenging, but is aided by their characteristic DNA methylation profile (DMP). An MPNST-like group, characterized by retained H3K27me3 expression, was recently recognized. To evaluate the diagnostic usefulness of DMP in pediatric/juvenile MPNSTs, we selected pediatric/juvenile malignancies from the Bambino Gesù Children's Hospital DMP database. DMP revealed unexpected molecular heterogeneity in histologically homogenous MPNSTs/Atypical neurofibromas, while samples with MPNST-like DMP manifested histological diversity. In conclusion, DMP is useful in diagnosing MPNST, discriminating morphologic mimics classified as MPNST in premolecular era, and investigating the MPNST-like ‘hybrid’ group in pediatrics. Bisulphite converted DNA from the 42 samples were hybridised to the Illumina Infinium MethylationEPIC Beadchip v1