RB1 and small cell lung carcinoma: Due to the morphological, genetic, and immunohistochemical similarities between SCBC and small cell lung cancer, such as chromogranin, synaptophysin, and CD56 (neural cell adhesion molecule) positivity or lesions in the RB1 (RB transcriptional corepressor 1) and TP53 (tumor protein p53) gene, treatment strategies for SCBC are frequently adapted from small cell lung cancer protocols [1,4,5].