Lung adenocarcinoma stage IV is clinically referred to as lung adenocarcinoma stage IV. According to TNM staging criteria, the criteria for lung adenocarcinoma stage IV are any T any N, as well as the presence of pleural spread, or distant metastasis, or the presence of satellite nodules in the contralateral lobe of the primary tumor. Lung adenocarcinoma is one of the types of lung cancer, and staging of lung adenocarcinoma is of great practical significance to the treatment of the disease as well as to the judgment of the prognosis of the disease. The staging of lung adenocarcinoma is evaluated according to the location and size of the primary tumor, lymph node metastasis and extrapulmonary tumor cells. According to TNM staging, stage IV lung adenocarcinoma belongs to stage IV lung adenocarcinoma regardless of the location and size of the primary tumor and regional lymph node metastasis, as long as there is pleural dissemination of tumor cells, or distant metastasis other than lungs and pleura, or satellite nodules occurring in the opposite lobe of the primary tumor. Lung adenocarcinoma stage IV belongs to the advanced stage and has a poorer prognosis. However, no matter what the individual’s condition is, patients with lung adenocarcinoma should cooperate with doctors for treatment immediately.