Long-standing ground glass nodules are not necessarily lung cancer. Lung glass nodules are the result of CT examination of the lungs, which suggests that there are nodules in the glass of the lungs, but they are not necessarily caused by lung cancer. Besides lung cancer, they may also be caused by inflammation, hemorrhage, and fibrosis of the lungs, which may lead to lung grinding glass nodules. If MGN is lung cancer, the imaging examination will show that the area of MGN will gradually increase, the diameter of MGN will increase, the number of MGN will increase, the MGN will mainly have short burrs, and it is lobed, and there is a depression sign in the pleura. If you are worried about lung cancer, it is advisable to consult a surgeon and analyze the cause by lung biopsy under the supervision of a surgeon.