Structural Development in Gliomas

In a morphological study of tumors the purely cytological characteristics, the neoplastic structures formed by the tumor cells, the gross aspects of growth and extension of the tumor, the stages of architectural and cellular development may each be especially considered. Most tumors are classified by their structural characteristics; thus one speaks of adenocarcinoma, scirrhous carcinoma, alveolar carcinoma, etc. Gliomas, on the contrary, since the work of Bailey and Cushing (2), are classified essentially on the basis of cytologic or even histogenetic characteristics. Recently investigators have become interested in the study of the developmental stages of neoplastic structures and the laws regulating their evolution. Ewing (8) has insisted upon the importance of studying “developmental stages, variations in structures, age, rate of growth and local reactions” in tumors. W. Fischer and his pupils have presented, for the first time, a series of investigations on the laws governing structural development in certain adenocarcinomas (3, 5, 7, 9, 11, 19). For several years we have made a systematic study of the structural evolution of the gliomas (22, 23, 24, 25, 26). This group of tumors, because of the enormous structural variability found even in a single neoplasm, presents a fascinating problem. Our research has had a double purpose: first, to analyze the laws governing structural development in gliomas; second, to attempt the application of these rules of growth to tumors in general. Because gliomas grow in an organ in which the tissue structures are both variable and highly differentiated, they are especially favorable for a study of the influence of preexisting structures on the architectural evolution of the tumor.