Intraoperative consultation for nervous system lesions.

The pathologist responsible for nervous system intraoperative consultations must know basics of the clinical history, details of the location and imaging characteristics of the lesion, and must be familiar with known clinicopathologic entities. Although cytologic and frozen section techniques have not changed significantly in the past 15 years, significant advancements in neuroimaging have greatly improved the ability to generate an accurate preoperative differential diagnosis. Such information can greatly aid the pathologist during intraoperative consultation. This review concerns the intraoperative cytologic and frozen section findings of the major clinicopathologic entities encountered in surgical neuropathology. While neoplastic processes of the central nervous system will be emphasized, important non-neoplastic conditions that mimic brain tumors will also be covered. A basic clinicopathologic approach to successful neurosurgical intra-operative consultation is provided.