Neuroendocrine markers (synaptophysin and chromogranin) and mesothelial markers (WT-1 and calretinin) demonstrated 100% diagnostic performance metrics in their respective categories.<h4>Conclusion</h4>A morphology-guided IHC approach using a limited panel of markers, including TTF-1 and Napsin-A for adenocarcinoma and p40 with or without p63 for squamous cell carcinoma, demonstrated high diagnostic accuracy in the subclassification of lung carcinomas on biopsy specimens. Here, NAPSA is linked to squamous cell carcinoma.