The acknowledged worldwide standard for classifying and grading brain neoplasms remains the landmark WHO Classification of Tumors of the Central Nervous System [1], and the most recent issued edition (2007) introduced a number of significant changes in brain tumor grading, with 8 new neoplasms and 4 new variants, as well as several redefinitions or clarifications of existing entities. Given this foundation, for me one of the most valuable resources in CNS grading, besides the seminal WHO Classification [1], is Anne Osborn (University of Utah School of Medicine) and colleagues' excellent recent 2012 review, commentary and update of the WHO 2007 grading system [2], written for the practicing neuroradiologist. There are many other fine reviews, but these two together are an exceptional point to start with.
REFERENCES
1. Louis DN, Ohgaki H, Wiestler OD, et al. WHO Classification of Tumours of the Central Nervous System. Lyon, France: International Agency for Research on Cancer 2007.
2. Osborn AG, Salzman KL, Thurnher MM, Rees JH, Castillo M. The new World Health Organization Classification of Central Nervous System Tumors: what can the neuroradiologist really say? AJNR Am J Neuroradiol 2012; 33(5):795-802.