Intraoperative consultation of central nervous system lesions. Frozen section, cytology or both?

Objective: Frozen section is the traditional method of assessing central nervous system (CNS) lesions intraoperatively. Our aim is to determine the diagnostic accuracy of frozen section and/or cytological evaluation of CNS lesions in our center.

Study Design: A total of 157 patients with CNS lesions underwent open surgical biopsy or excision in our center during a period of 2 years (2012-2013). All specimens were studied cytologically; of these specimens, 146 cases were also examined by frozen section. Cytology and frozen section slides were studied separately by two general pathologists who were blind to final diagnoses. The final diagnoses were based on permanent sections and IHC studies.

Results: The accuracy rates of frozen section analysis and cytological evaluation were 87% and 86%, respectively. If the two methods were considered together, the accuracy rate improved to about 95%.

Conclusions: Cytological evaluation is an acceptable alternative to frozen section analysis and also a great supplement to the diagnosis of CNS lesions.