Cytological Diagnosis of Lung Cancer: The Diagnostic Accuracy and Pitfalls

The role of respiratory cytology is to detect and classify pulmonary disease, with an emphasis of neoplastic disease, so that proper therapy can be instituted. As in many branches of cytology, the recognition of malignancy in the cells obtained from the respiratory tract is more straightforward than identifying the type of tumor cell. It is important to accurately determine the true cytopathological cell type in cases of primary lung cancer and to know the accuracy of the diagnosis achieved by the cytological procedures. The well differentiated tumors have characteristic cytoplasmic and nuclear abnormalities that enable physicians to firmly categorize these lesions, as in squamous cell or adenocarcinoma, but some moderately and most poorly differentiated tumors show few distinctive features. This article reviews the malignant and reactive pulmonary cytologic findings and we also report on some of their pitfalls and the cytologic criteria.