Definitions and Synonyms Melanocytic neoplasms of the central nervous system (CNS) arise from the population of leptomeningeal melanocytes that are scattered throughout the arachnoid membranes. Lesions can manifest as diffuse disseminations within the subarachnoid space or as solid masses, and…
Brief Historical Overview The neuronal and mixed glioneuronal category of central nervous system (CNS) tumors has been expanding over the past 60 years. In the first edition of the Armed Forces Institute of Pathology (AFIP) fascicle (1952) and the first…
Introduction Not all brain tumors fit neatly into well-defined diagnostic categories within accepted classification systems. Such is the case with the three rare neoplasms discussed in this chapter: angiocentric glioma, astroblastoma, and chordoid glioma. Each of these has a unique…
The designation of “astrocytoma” includes a small subset of tumors with astrocytic differentiation that are better circumscribed than the diffuse astrocytomas. These tumors arise in the pediatric population most frequently, but are also occasionally noted in adults and include the…
Introduction and Brief Historical Overview The infiltrative, or “diffuse,” gliomas include astrocytomas and oligodendrogliomas. Taken together, these are the most frequent primary neoplasms of the central nervous system (CNS) parenchyma. Bailey and Cushing first classified these neoplasms by their cellular…
Introduction The practice of surgical neuropathology can be challenging for the generalist and specialist alike. Much of the difficulty results from the intrinsic complexity of the human central nervous system (CNS), an organ that is unrivaled in regional variation and…
CNS Tumor Classification Schemes and Additional “Neuropathology Patterns” The first comprehensive classification of nervous system tumors, formulated by Percival Bailey and Harvey Cushing in 1926, was founded on presumed parallels between embryologic and neoplastic cells. In large part, this histogenetic…