ALK and lung adenocarcinoma: The aim of this study was 1) to evaluate the clinicopathological and histological features of 80 cases of ALK-rearranged resected lung adenocarcinomas, 2) to compare these features with those of ALK-negative tumors expressing well-known driver mutations associated with lung adenocarcinoma, and 3) to investigate the correlation between molecular subtype and histological features of lung adenocarcinoma based on the new IASLC/ATS/ERS classification.