Squash Smear Technique in Rapid Intraoperative Diagnosis of Brain Tumors

Abstract

The role of rapid intraoperative diagnosis is crucial to neurosurgeons to not only define surgical approach, but also to ensure that minimum injury is caused to normal structures surrounding the lesion. Intraoperative cytology has been shown to be an important diagnostic modality. Squash smears are gaining popularity with increasing use of stereotactic biopsies which give limited tissue yield. The study was designed to assess the accuracy of intraoperative squash smear in the rapid intraoperative diagnosis of brain tumors. 100 consecutive cases of CNS tumors in which the tissue was removed at craniotomy or burr-hole biopsy were studied. The age range of the cases varied from 1 to 80 years. The diagnostic accuracy of squash smears was found to be 91%.In all the cases, clinicoradiological correlation was done with smear diagnosis. Smears were stained with 1% toluidine blue/H&E. In all the cases, results were compared with the paraffin section prepared from tissue remaining after the squash smears were made. Immunohistochemistry/Immunocytochemistry was done as needed.