The role of the cytopathologist in subtyping and epidermal growth factor receptor testing in non-small cell lung cancer: An institutional experience.

More than 90% of NSCLC can be sub-typed on cytology samples with the help of immunochemistry. The sensitivity of TTF-1, p63, CK5/6 and CK7 was 73.3%, 80%, 100% and 100%, respectively. The specificity of TTF-1, p63, CK5/6 and CK7 was 100%, 86.6%, 86.6% and 93.3%, respectively. TTF-1 is highly specific, and almost 80% of NSCLC-NOS cases can be sub-typed using TTF-1 and p63. EGFR mutations can be detected in cytology samples, and 16.7% samples were positive for EGFR mutations.