Cytological interface of diffusely infiltrating astrocytoma and its marginal tissue.

Cytological differences between infiltrating lesions of the diffusely infiltrating astrocytoma (DIA) and reactive gliosis at its periphery have not yet been established. We compared histological specimens from cytological crush preparations of 200 brain tumors to characterize the cytology of the DIA and to discriminate it from reactive gliosis. First, the cytological findings of the backgland brain parenchyma were assessed. Second, we looked at the nuclear characteristics of the DIA, comparing them with those of other brain tumors. Third, the cytology of the infiltrating DIA was assessed together with brain parenchymal elements. Finally, we characterized discriminative points of the area of infiltration of the DIA versus those of the reactive gliosis. In addition, we assessed the relations between the cytological findings of the DIA and its MRI images. The cytological findings of this area are important because the surgeon may have to make a rapid diagnosis regarding the existence of the tumor.