Occult pN2 disease in lung cancer patients: a wide range of diseases endangering the long term prognosis

Occult pN2 disease is the discovery of non-small-cell lung cancer (NSCLC) metastases in mediastinal lymph nodes (LNs) considered clinically disease free (cN0) after clinical staging (cTNM) established by increasingly precise work procedures, such as current imaging studies [computed tomography (CT) and positron emission tomography (PET)] and bronchoscopy or esophagoscopy with ultrasound directed biopsies (EBUS, EUS).