ALK and lung adenocarcinoma: Lung adenocarcinomas with ROS1 rearrangement were mainly solid in density (19 of 23, 83%) (Figs. 1, 2 and 3), similar to EGFR-mutant (73%) or ALK-rearranged (88%) tumors, and tended to have a lobulated border (15 of 23, 65%).