N3 nodes will be sampled first and then N2 nodes to avoid contamination in lung cancer patients. The materials obtained by EBUS-guided TBNA will be smeared on slides. These slides will be air-dried and Diff-Quik (American Scientific Products, McGaw Park, IL) staining will be used for ROSE. Additional smears will be prepared for Papanicolaou staining and any remaining sample will be placed in 10% formalin for histologic evaluation. The results of ROSE were compared with the results of the final pathologic diagnosis. (17) Aspiration specimen was considered "insufficient" if there were not an adequate number of lymphocytes on the smear. Diagnosis as "malignant" in cytologic examination was considered as the "final diagnosis". For the patients whose EBUS-guided TBNA results were negative for malignancy, more invasive procedures such as mediastinoscopy will be done to confirm the diagnosis or radiologic follow-up on the outcome of the LNs for at least 6 months. On follow-up, LNs that persisted in size, diminished, or resolved were considered benign. A diagnosis of tuberculosis or sarcoidosis will be made based on cytopathology that showed the presence of caseating or noncaseating granuloma, in addition to clinical, radiological, and microbiological findings.