Correlation of intraoperative cytological and final histological diagnoses

Abstract

Objective: Intraoperative cytology is a cost-effective, rapid, and easy technique, and studies have shown good correlation between intraoperative cytology and histology. We undertook this study to compare the intraoperative cytology diagnoses of brain lesions made in our unit over a 10-year period with the definitive histological diagnoses. The aim was to determine the degree of accuracy of this procedure.

Study design: This is a retrospective study of intraoperative neuropathology consultation cytology smears or imprints and histology of 69 cases obtained over a 10-year period. Cytology smears were stained using both Papanicolaou and Giemsa. Histology sections were prepared from routine formalin-fixed paraffin- embedded tissue and stained using H and E method. Each of the smears and histology samples were assessed by at least two pathologists. Cytological diagnosis was correlated with final histological diagnosis. The sensitivity and specificity of cytological diagnosis was evaluated using final histological diagnosis as gold standard.

Results: Correlation was strongest with inflammatory lesions followed by low-grade neoplasms. High-grade neoplasms also showed good concordance, but the degree of correlation was lower than in the other categories. Misdiagnosis was commonest with benign tumors.

Conclusion: Intraoperative cytology is a relatively simple, reliable, and accurate diagnostic technique and should be more commonly used, particularly in low-resource settings. Diagn. Cytopathol.