Comparison of smear cytology with histopathology of the CT guided stereotactic brain biopsy

The study was undertaken to determine the accuracy of cytological diagnosis of CNS lesions by comparing it with the final histopathological diagnosis of CT guided stereotactic brain biopsy. Squash preparations were prepared from 25 cases of CNS lesions operated in two years. These included 18 astrocytomas, 1 metastatic deposits, 1 epidermoid cyst, 1 Toxoplasmosis, 1 granulomatous inflammation and 3 cases showing normal brain parenchyma. The cytological diagnosis was available to the neurosurgeon within 10 minutes. The cytohistological correlation with paraffin block sections worked out to be 92%. Thus, this proved to be a fairly reliable and rapid method for immediate intra-operative diagnosis.