[Cytopathologic diagnosis of neuroepithelial tumors by the smear technique]

We studied 198 cases of neuroepithelial tumours with intra-operative diagnosis made by smears comparing the accuracy rates with the final paraffin section diagnosis. In 90.6% of cases the final diagnosis obtained on paraffin preparations was similar to that made on smears. In the group of cases with cytological diagnosis not confirmed by paraffin sections the majority of cases were unlike to affect immediate neurosurgical management, and represent mainly differences in grading of astrocytomas and mixed gliomas. The cytological diagnostic criteria are discussed together with the main difficulties for the interpretation of this valuable approach to intra-operative neurosurgical diagnosis.