Pathology and Classification of Tumors of the Central Nervous System

Abstract

The characterization of distinct genetic and epigenetic profiles in different types of tumors of the central nervous system (CNS) has revealed novel diagnostic, prognostic, and predictive molecular biomarkers for improved tumor classification and better prediction of therapy response and outcome in the individual patient. This chapter provides an overview of the pathology and molecular genetics of all major types of CNS tumors. It also summarizes the current state of CNS tumor classification according to the revised World Health Organization (WHO) classification of 2016 and explains the novel approach of combining histologic features and molecular information in an integrated histomolecular diagnosis. In addition to characteristic macroscopic, histologic, and immunohistochemical features, diagnostically relevant molecular biomarkers are detailed for each CNS tumor entity. Moreover, the clinical relevance of molecular alterations and the perspectives of novel high-throughput genetic and epigenetic profiling approaches for comprehensive molecular diagnostics are discussed. Novel developments concerning the identification of newly defined tumor entities, as well as recent updates on CNS tumor classification according to recommendations of the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-Now), are considered. Thus, this chapter provides a timely and comprehensive summary of the current state of pathology and classification of tumors of the CNS.