Utility of Immediate Cytologic Diagnosis of Lung Masses Using Ultrafast Papanicolaou Stain

Purpose: At Kagawa University Hospital we conduct immediate cytology using ultrafast Papanicolaou (U-Pap) stain when collecting cytology specimens by bronchoscopy or CT-guided needle aspiration, and report here an investigation of its utility.

Methods: The subjects were 503 patients for whom a final histopathological diagnosis could be made, taken from among 568 immediate cytology patients between July 2000 and June 2008. In immediate cytology at our hospital, a cytotechnologist goes to the bronchoscopy room just before tissue is collected. U-Pap stain is done immediately and examined microscopically. A tentative report is made orally on the spot as to the specimen adequacy, whether it is benign or malignant, and the presumed histopathological type.

Results: Of the 503 patients, the sample was inadequate in only two cases and there were no false positives. With respect to diagnostic accuracy, sensitivity was 82.9%, specificity was 100%, and the correct diagnosis rate was 85.6%. For lesions ≤3 cm, sensitivity was 77.2%, specificity was 100%, and the correct diagnosis rate was 81.3%, and for lesions ≤2 cm sensitivity was 74.7%, specificity was 100%, and the correct diagnosis rate was 81.3%. Diagnostic accuracy was thus maintained even for small lesions. No false positive case was detected.

Conclusion: Because immediate cytology enables more precise sample collection, it is thought to be a useful technique that leads to improved diagnostic accuracy, while also improving the technical skill of the doctor collecting samples through immediate feedback.