Utility of intra-operative consultations for the diagnosis of central nervous system lesions

The inherent soft nature of the central nervous system (CNS) renders poor-quality frozen sections. Cytology has been shown to be of great value in intra-operative consultations of CNS pathology. The current study was undertaken to examine the utility of intra-operative consultations regarding CNS lesions, comparing the usefulness and limitations of frozen section and cytology techniques. A retrospective study of 103 cases of CNS intra-operative consultations was performed. Concordance between the intra-operative diagnosis and the final diagnosis was seen in 94% of cases. Most discrepancies were due to failure to recognize atypia in meningiomas. The cytology technique was more useful for astrocytomas, small round cell tumors, and certain metastases. The frozen section technique was better for the diagnosis of meningiomas, reactive lesions, ependymomas, and most metastatic lesions. Using a combination of the two techniques is most beneficial.