MKI67 and metastatic malignant neoplasm in the lymph nodes: Nonparametric tests were performed to identify features that showed significant differences between the three classes of Ki67 (Ki-67 < 3 (Group 1), 3 ≤ Ki-67 ≤ 20 (Group 2) and Ki-67 > 20 (Group 3)) or between the presence or absence of mediastinal lymph-node metastases.