From Banding to BAM Files: Genomics Informs Diagnosis and Precision Medicine for Brain Tumors.

Tumors of the central nervous system (CNS) have been historically classified according to their morphologic and immunohistochemical features. In 2016, updates to the classification of tumors of the CNS by the World Health Organization revolutionized this paradigm. For the first time, genomic findings, whether whole-arm chromosomal aberrations or single nucleotide variants, represent a necessary and critical component of diagnosis, contributing or superseding histologic findings. These updates stem from decades of technical innovation and genomic discovery. During this time, there has been a dramatic expansion and evolution in clinical genomic assays for these tumors, informing diagnosis and guiding therapeutic management.