Diagnostic accuracy of fine needle aspiration cytology versus concurrent core needle biopsy in evaluation of intrathoracic lesions: A retrospective comparative study

Background: Transthoracic fine needle aspiration (FNA) cytology and core needle biopsy (CNB) are two commonly used approaches for the diagnosis of suspected neoplastic intrathoracic lesions. This study compared the diagnostic accuracy of FNA cytology and concurrent CNB in the evaluation of intrathoracic lesions. Materials and Methods: We studied FNA cytology and concurrent CNB specimens of 127 patients retrospectively, using hematoxylin and eosin (H&E), immunohistochemistry, and, on certain occasions cytochemistry. Information regarding additional tissue tests was derived from the electronic archives of the Department of Pathology and Laboratory Medicine as well as patient records. Diagnostic accuracy was calculated for each test. Results: Of 127 cases, 22 were inconclusive and excluded from the study. The remaining 105 were categorized into 73 (69.5) malignant lesions and 32 (30.5) benign lesions. FNA and CNB findings were in complete agreement in 63 cases (60). The accuracy and confidence intervals (CIs) of FNA and CNB for malignant tumors were 86.3 (CI: 79.3-90.7) and 93.2 (CI: 87.3-96.0) respectively. For epithelial malignant neoplasms, a definitive diagnosis was made in 44.8 of cases by FNA and 80.6 by CNB. The diagnostic accuracy of CNB for nonepithelial malignant neoplasms was 83.3 compared with 50 for FNA. Of the 32 benign cases, we made specific diagnoses in 16 with diagnostic accuracy of 81.3 and 6.3 for CNB and FNA, respectively. Conclusions: Our findings suggest that FNA is comparable to CNB in the diagnosis of malignant epithelial lesions whereas diagnostic accuracy of CNB for nonepithlial malignant neoplasms is superior to that for FNA. Further, for histological typing of tumors and examining tumor origin, immunohistochemical work up plays an important role