Atypical Small Cell Lung Cancer: A New Malignancy Characterized by Chromothripsis, Carcinoid Tumors, and Wild-type RB1 and TP53

Small cell lung cancer (SCLC) and pulmonary carcinoid tumors are traditionally seen as unrelated, with SCLC linked to smoking and characterized by biallelic loss of RB1 and TP53 and rapid progression. Rekhtman and colleagues upend these assumptions by discovering an "atypical" SCLC that arises in nonsmokers with intact RB1 and TP53 loci, chromothripsis-induced oncogene amplifications on extrachromosomal DNA, and frequent synchronous carcinoid tumors. See related article by Rekhtman et al., p. 83.