Regressive Processes

Abstract

Regressive changes are by no means rare in brain tumors and can make tumor tissue unrecognizable or at least almost unclassificable. Yet, in both type and extent they are quite characteristic for each of the various subtypes of neuro-epithelial tumors. Knowledge of these processes is therefore both necessary and helpful in evaluating biopsies from altered tissues. Regressive changes, such as calcification, necrosis, and cyst formation, may permit localization of a tumor by x-ray or CT. They can also be used in differential diagnosis, since as stated above, the degenerative processes are to a certain extent type specific.