TP53 and small cell lung carcinoma: Strong TP53 staining and negative RB1 staining were observed in both LUAD and SCLC samples, but FISH only identified MYC amplification in SCLC tissue.<h4>Conclusion</h4>We consider the combined presence of MYC amplification with mutations in TP53 and RB1 as drivers of SCLC transformation.