Evaluation of Intraoperative Cytological Smears for Diagnosis of Brain Tumors with Special Reference to Immunohistochemistry

CONTEXT: Brain tumors are heterogeneous group of benign and malignant tumors of glial, meningeal, neuronal, embryonal, and lymphoid origin. Rapid intraoperative diagnosis of the nature of the tumor helps the surgeon to plan the extent of surgery and modify it accordingly. AIMS: (1) To establish the validity and reliability of squash cytology in the intraoperative diagnosis of brain tumors. (2) To correlate with histopathological report and immunohistochemistry (IHC) profile. SETTINGS AND DESIGN: Prospective, observational study. SUBJECTS AND METHODS: prospective, observational study was conducted in the Department of Pathology in collaboration with the Department of Neurosurgery of a tertiary care hospital. One hundred and seven patients with symptomatic or radiologically detected brain tumors were included in the study. Intraoperative squash smears were stained with hematoxylin and eosin and rapid papanicolaou stain. Cytological diagnosis was recorded and communicated to the surgeon. Cytological findings were corroborated with histological findings subsequently. GFAP, Ki-67, and ER-PR IHC were used as additional markers. STATISTICAL ANALYSIS USED: Software used in statistical analysis of our study was MedCalc version 11.6 (Mariakerke, Belgium: MedCalc Software 2011). RESULTS: A total of 107 cases were included in the study. Meningioma was the most common lesion. Overall sensitivity in our study to diagnose benign and malignant tumors was 94.7% and the specificity is 97.6% with positive and negative predictive value of 94.7% and 97.6%, respectively. Diagnostic accuracy was highest in pituitary adenoma. CONCLUSIONS: The combination of meticulous evaluation of clinical, radiological, and cytological findings helps in accurate and rapid diagnosis of brain tumors.