What is metastatic lung cancer

Metastatic lung cancer refers to the metastasis of malignant tumors originating from other parts of the body to the lungs. It is quite common. According to relevant statistics, about 20% to 30% of patients who died of malignant tumors had lung metastasis. Common primary malignant tumors include gastrointestinal tract, urogenital system, liver, thyroid, breast, bone, soft tissue, skin, etc.

The time of lung metastasis of malignant tumors varies. Most patients metastasize within 3 years after the primary cancer appears, a few patients metastasize within 5 to 10 years after the onset of the disease, and a few patients discover lung metastasis lesions before the primary cancer is found. Lung metastatic lesions are mostly multiple, of varying sizes, uniform density, and clear contours. In a few cases, there is only a single lesion in the lung, and the X-ray manifestations are similar to those of peripheral primary lung cancer.

In addition to the symptoms of the primary tumor, most metastatic lung cancers have no obvious special clinical symptoms. Generally, when following up patients with primary tumors, lung X-ray examinations are performed and a small number of patients have symptoms such as cough, blood in sputum, fever, and dyspnea. The diagnosis of metastatic lung cancer is based not only on X-ray manifestations, but also on the diagnosis and medical history of the primary cancer. In addition, sputum cytology can also be used for diagnosis, but the positive rate is low. Bronchoscopy is of little help in diagnosis. Special attention should be paid to the differential diagnosis of single pulmonary metastatic cancer lesions and primary peripheral lung cancer.