A study of imprint cytology in computerized tomography-guided coaxial core biopsies of the lung and mediastinal lesions

Background: Image-guided core biopsy (CB) is a reliable technique for the diagnosis of various deep-seated lesions. It allows precise localization and documentation of the biopsy needle and target lesions. CB imprint cytology (IC) is a rapid, reliable, and accurate technique which enhances the known benefits of CB. Aims: The aim of this study was to study the diagnostic accuracy of IC when performing computerized tomography (CT)-guided coaxial CB of lung and mediastinal lesions and to assess whether it could optimize the biopsy procedure. Methodology: A total of 30 CT-guided core biopsies with imprint smears were studied. All biopsies were performed using 18 gauge coaxial needle and spring loaded gun. On-site assessment for the adequacy of the sample was done by the pathologist after staining with toluidine blue. The imprint smears were compared with the histopathology (HP) of CB specimens and the accuracy, sensitivity, specificity, and positive and negative predictive values were evaluated. Results: The overall accuracy of IC when compared to the HP was 96.7%, with a sensitivity of 100%, specificity of 85.7%, positive predictive value of 95.8%, and negative predictive value of 100%. The value of P< 0.001. Conclusion: With an on-site approach, IC helps to assess the adequacy of the sample and reduce the number of passes and the possibility of redo procedures. Since the sensitivity of IC is high, it provides a valuable lead time to the clinician, for planning the management protocols, before a final histopathological diagnosis is available.