ROS1 and Pleural effusion: With regard to imaging features other than the primary tumor, ROS1-rearranged tumors more frequently showed advanced intra- and extrathoracic lymph node metastases, pleural effusion, and pericardial metastases compared to EGFR-mutant tumors, although these differences were not observed between ROS1- and ALK-rearranged tumors.