Intraoperative consultation, cytologic preparations, and frozen section in the central nervous system

Context. - Intraoperative evaluation of lesions in the central nervous system requires the correlation of clinical, radiologic, and histologic data and knowledge of clinicopathologic entities and their common locations. Advances in neuroimaging during the last 20 years have revolutionized the diagnosis and treatment of central nervous system diseases. The diagnosis and treatment of patients have improved because of these changes and have allowed access to regions that were previously inaccessible. These new approaches have placed the pathologist in a key role in the diagnosis and treatment of patients with central nervous system lesions. Assessment of the adequacy of the material, particularly for stereotactic biopsies, is necessary, and a combination of cytologic imprint preparations and frozen sections are often used. This review discusses many of the issues involved in intraoperative consultation and provides a simplified approach to the differential diagnosis of a variety of central nervous system lesions that may be encountered intraoperatively. Objective. - To provide guidelines for and address potential pitfalls in the intraoperative management of the central nervous system. Data Sources. - Author's experience and pertinent literature. Conclusions. - Careful assessment of the gross specimen coupled with prudent use of frozen sections and cytologic imprint preparations is pivotal to reducing intraoperative error rates and preventing needless anxiety for the patient.