Morphological changes in anaplastic gliomas treated with radiation and chemotherapy.

The effects of antineoplastic treatment on gliomas are related to tumour cell cycle and proliferation kinetics, glioma tissue architecture, and the surrounding environment. Morphological changes induced by radiation and chemotherapy are characterized by cell necrosis and severe alterations in cell and nuclear morphology caused by changes in the cell kinetic parameters which, however, may also occur spontaneously in untreated anaplastic gliomas. Comparative studies of cytological imprints and routine histological preparations of biopsy and autopsy specimens were performed in four groups of anaplastic astrocytomas and glioblastomas (78 cases) with postsurgical irradiation, combination chemotherapy, and CCNU treatment, and without specific postsurgical treatment (control group). Following radiation and chemotherapy, in addition to increased necrosis and vascular response, a variety of characteristic but nonspecific changes were observed in cell and nuclear morphology with prominent formation of multinucleated giant and monstrous cells, irregular and hyperchromatic nuclei, and severe cytoplasmic degeneration indicating both inhibition of cell division and cell damage. Statistically significant findings were a posttreatment increase in the number of multinucleated giant and monstrous cells and a decrease in the number of mitoses. These changes were more pronounced after chemotherapy than after radiation, while no significant dissimilarities were found between combination chemotherapy and CCNU. The implications of these changes on the mechanisms of antitumour treatment in anaplastic gliomas are discussed.