Lung Cancer: Lymphadenopathy and Extrapulmonary Involvement

Abstract

Lymphadenopathy and extrapulmonary involvement may be presenting manifestations of advanced lung cancer. Central tumors such as squamous cell carcinomas and small cell carcinomas often exhibit ipsilateral hilar and mediastinal lymphadenopathy. Metastatic lymphadenopathy may exhibit subtle findings on radiography but is readily identified on CT, MRI and PET-CT. Lymphadenopathy in the setting of lung cancer portends a poorer prognosis compared with lung cancer without lymph node involvement. The differential diagnosis includes reactive lymphadenopathy from infection, granulomatous lymphadenopathy from sarcoidosis and malignant lymphadenopathy from metastatic disease and lymphoma. Advanced lung cancer may exhibit extrapulmonary involvement as the first manifestation of disease. Central lung cancers may directly invade the mediastinum and its organs and vessels. Peripheral lung cancers may invade the adjacent chest wall structures. Pleural and pericardial involvement may also occur and often manifests with effusion. Metastases to upper abdominal organs may be identified on chest CT. PET-CT allows identification of distant metastases.