The purpose of pathologic evaluation of lung cancer in the new NCCN non-small cell lung cancer guidelines includes determining tissue classification, TNM stage, borderline status, and molecular abnormalities. The lung cancer classification emphasizes avoiding the use of independent diagnostic terms for NSCLC and minimizing the use of unclassified terms, and instead specifying the tissue staging (adenocarcinoma, squamous carcinoma, or large cell carcinoma) whenever possible. “The diagnosis of “NSCLC squamous cell predominant” or “NSCLC adenocarcinoma predominant” can be clarified by immunohistochemical staining.