Smear preparation of intracranial lesions: a retrospective study of 306 cases.

A cytohistological correlation with determination of accuracy rate of smear preparation result was done in a retrospective study of 306 cases of intracranial tumors. Cytomorphology of few new entities of CNS tumors are described. The cytological features and WHO grading of the tumors were described on smear preparation. The cases with discrepancy in cytological and histological diagnosis were reviewed again and a final possible diagnosis on smear preparation which should have been given is discussed. The clinical details like the age, sex, and site of the tumors were analyzed. The age range of the patients was from 3 years to 63 years with male:female ratio of 1.5:1. Of the total 306 cases, a cytohistological correlation was seen in 93% cases. Twenty-two (7.3%) cases showed discrepancy between the crush preparation diagnosis and final histopathological diagnosis. Majority of the tumors were located in the cerebral hemisphere (56%) and the most frequently diagnosed tumor was astrocytoma, in particular, pilocytic astrocytoma (18.5%) followed by meningioma (11.9%), medulloblastoma (7.3%), anaplastic oligodendroglioma (5%), ependymoma (4.3%), pituitary adenoma (3.3%), schwannoma (3.3%), etc. A few rarer tumors, in central nervous system like differentiating neuroblastoma, pineocytoma, atypical choroid plexus papilloma, piloxmyxoid astrocytoma, rosette forming glioneuronal tumor, etc. are also described, Smear/crush preparation is a very effective, simple, rapid and reliable technique for the diagnosis and WHO grading of central nervous system tumors. Diagnostic accuracy of cytology with final histopathological report is established with accuracy rate of 93%.