The physical examination report shows lung shadows? See what the doctor says

Author: Zhao Liqiang, Chief Physician, Beijing Chaoyang Hospital, Capital Medical University

Reviewer: Zhang Yu, researcher at Chinese Center for Disease Control and Prevention

Many people think they have lung cancer when they find lung shadows during lung imaging. This is not the case. Inflammatory diseases such as lung infection, congenital lung dysplasia such as pulmonary sequestration, and old lung lesions such as calcification can all appear as lung shadows in imaging. However, for some high-risk groups, if they find lung shadows, they must be alert to lung cancer!

1. People who smoke for a long time. As we all know, tobacco contains carcinogens such as benzopyrene, and studies have now proven that smoking is a clear cause of lung cancer.

2. People who are exposed to smoke and dust for a long time. Some occupations will be exposed to some carcinogens, such as carcinogens produced during the combustion of coal; or some workers are exposed to asphalt, tar, etc. for a long time, including workers in steel mills, coking plants, and power plants. The incidence of lung cancer is also higher than that of ordinary people.

3. People with a family history of lung cancer. Smoking or exposure to carcinogens can damage the DNA of alveolar cells, causing them to proliferate abnormally and become cancerous. Family inheritance is defective from a genetic perspective, and such people are also prone to cancer when they reach a certain age.

When lung shadows are found, a preliminary judgment can be made based on the imaging characteristics whether it is lung cancer.

For example, if the shadow in the lung is larger than 3 cm, it is called a mass. If the mass is relatively large and expands into the surrounding tissues and grows aggressively, lung cancer should be highly considered.

Figure 1 Original copyright image, no permission to reprint

For example, squamous cell lung cancer usually grows in the hilum of the lungs, mainly through the mutation and proliferation of tracheal lining cells, and then slowly grows. Generally speaking, it is located in the trachea, that is, the hilum of the lungs, close to the heart. When it grows, it will block the bronchus, which can usually be diagnosed through X-ray examination.

Of course, some lung cancers are peripheral lung cancers, which do not grow on the central bronchi. For example, most adenocarcinomas grow around the lungs, on the edge of the lungs. The density of the lesions is relatively higher than that of inflammation. In addition, there is tissue infiltration and invasion, which pierces out like a burr, and the boundary with the surrounding tissue is unclear. There is a layer of visceral pleura on the surface of the lungs. When lung cancer approaches the pleura, it will pull the pleural tissue and shrink the pleura. In the late stage, there will be enlarged lymph nodes, invasion of lymphatic vessels, and then metastasis to nearby lymph nodes.

But generally speaking, we still need to do a bronchoscopy to directly see the lesion under the scope, and then take tissue and do pathology to find cancer cells before we can make a clear diagnosis.

If the shadow in the lung is less than 3 cm and has a relatively light density, it is called a ground-glass nodule. There are generally two types of ground-glass nodules in the lungs: uniform ground-glass nodules and uneven ground-glass nodules.

Uniform, as the name suggests, means that the density of the entire lesion is basically the same, which means that it may be adenomatous hyperplasia, which is the abnormal proliferation of normal lung cells slowly, but the proliferation is very stable. Uneven means that the abnormal proliferation will proliferate more at a certain point and less at another point.

When we do physical examinations now, many older people, especially those over 40 years old, have a higher chance of having ground-glass opacities. This is because for older people, the outside air stimulates the lungs for a relatively long time, so ground-glass opacities are more likely to occur.

Generally speaking, uniform ground-glass shadows have an 18% chance of being malignant, while uneven ground-glass shadows have a higher probability of being malignant, which may reach 60%.

Figure 2 Original copyright image, no permission to reprint

After the ground-glass nodules are found in the lungs, if the lesions are less than 5 mm and the density is relatively uniform, they can be observed. For example, a chest CT scan is done every three months, six months, or one year, and regular check-ups are done according to the doctor's advice.

For ground-glass nodules between 5 and 10 mm, the observation interval may be closer, for example, a chest CT scan must be performed every three months or six months to determine the lesion. If it grows, surgery may be required. However, for most people, especially those with uniform ground-glass shadows, they may not change from the age of 40 to the age of 80. Non-uniform ground-glass shadows are more likely to be malignant.

Of course, most people get nervous once they find out about it. Many patients will have anxiety symptoms, thinking about it every day, and can't eat or sleep. After observing for three months or six months, some people are so anxious that they finally hope to have surgery to remove it.

In addition, although the ground-glass opacity has not changed, it can only be removed if it is at the edge and under control. If it is in the center, that is, in the middle of the lung, no matter how small the lesion is, only one lung segment or one lung lobe can be removed, and the damage is relatively large.

Therefore, in principle, observation is recommended. Surgery is only recommended when there is a high possibility of malignancy or it has been confirmed to be malignant.