Accuracy of the smear technique in the cytological diagnosis of 650 lesions of the central nervous system.

The authors analyzed the results of 650 lesions of the central nervous system submitted to intraoperative cytological diagnosis by the smear technique. Cytological and paraffin section diagnoses were compared. The following statistical values were obtained: accuracy of 97.3%, sensitivity of 97.9%, specificity of 95%, positive predictive value of 99.1%, and negative predictive value of 89.6%. The authors comment on their main pitfalls using this cytological diagnostic procedure.