Neurooncology has become a science of such great proportions and indefinite limits as to include branches which widely diverge from one another. Therefore, it is not an easy task to fit it all into the narrow framework of a book, though the collaboration among scientists compensates partly for the varying depths of knowledge and ex perience in the individual disciplines. The principal characteristic of this work, how ever, is in casting "pathology" as the common nosographic link. Though scientific progress has brought us well past the nosography of brain tu of departure, the area of mutual understanding to mors, pathology remains the point which all students of neurooncology refer when laying out diagnostic, therapeutic, and research schedules. Neurologists, neurosurgeons, and neuroradiologists orient themselves only by referring to tumor types. Neurooncology treatises require ever greater numbers of authors in order to cover the different subject areas with uniform authority. Excellent texts are available today for this purpose. The present book is not, and does not wish to be, a treatise but rather aims at presenting different aspects of neurooncology from the perspective of pathology and its biological and clinical correlates. It expresses the author's experi ence in the study of brain tumors and their pathology and clinical characteristics. The emphasis dedicated to the subjects relates to the clinicopathological and theore tical importance.