Highways and strayways in classification of tumors of the central nervous system

A concise review of classifications of the central nervous system tumors is presented. Special attention has been paid to subsequent histological classification of CNS tumors prepared under auspices of the World Health Organization. The author points out a necessity of the modification of WHO classification from 1979, resulting from the accumulation of new clinical and pathological observations and data on one hand and from the progress of basic research concerning neoplasia in the nervous system on the other. The author stresses the clarifying and ordering values of the classification proposals and principles, treating critically some others. Separately, the histological malignancy grading systems are reviewed.