A tumor of 5cm in the lung is definitely considered very large. Generally, if the tumor in the lung is 5mm or more, the possibility of lung cancer needs to be considered. Generally, if the diameter of ground glass nodules is between 5mm-1cm, further examination is needed to identify the nature, and enhanced CT, angiography, etc. can be done. If burr-like or enhancement around the lesion is found to be more obvious, it suggests the possibility of malignant tumor and needs to be treated by surgery as soon as possible. For tumor of 5cm in lung, it is necessary to exclude the possibility of benign lesions such as inflammatory pseudotumor. However, sometimes, if it cannot be fully determined by imaging or lung aspiration alone, lobectomy should be considered. It is only through the pathology after surgery that it can be determined, if it is a malignant lung tumor. Many of these cases are very advanced and there is no way to operate, only to do palliative radiotherapy to control the progression of the disease.