ALK and metastatic malignant neoplasm in the lymph nodes: ALK rearranged tumors were more frequently associated with clinical stage III than EGFR mutated tumors (10/28, 35.7% vs 12/90, 13.3%, p = 0.008) and more commonly showed ipsilateral mediastinal or subcarinal lymph node metastasis (N2) compared with EGFR and KRAS mutated lung adenocarcinomas (15/28, 53.6% vs 20/90, 22.2%, p = 0.002 and 15/28, 53.6% vs 48/159, 30.2%, p = 0.016).