[Next generation sequencing in histopathology : Applications and methodological challenges]

The enormous increase in sequencing capacity due to the development of next generation sequencing technologies opens up new opportunities in the fields of histopathology, research, and diagnostics, but also poses huge challenges.The identification of genomic aberrations (point mutations, small insertions and deletions, fusion transcripts, and tumor mutation burden (TMB)) have already become a reliable part of routine molecular diagnostics. This will be supplemented by additional applications, namely gene amplifications, microsatellite instability, genomic signatures like homologous recombination deficiency (HRD), mRNA expression patterns, B‑ and T‑cell clonality, and DNA methylation. Challenges in preanalytics and the evaluation of assay sensitivity and specificity as well as proper curation of identified aberrations, which requires a new type of specialist, are presented and discussed.