What is a pulmonary nodule and how is it caused?

Lung cancer is one of the most serious malignant tumors that endanger human health. Although with the clinical application of targeted therapy and immunotherapy, the survival time of advanced lung cancer is obviously prolonged, but the overall five-year survival rate is still not optimistic. The most effective method of lung cancer is early detection, early diagnosis and early treatment. Therefore, early lung CT screening is an effective method to prevent and treat lung cancer, and with the popularization of CT, more and more pulmonary nodules are found. According to statistics, 1 out of every 500 people who underwent chest examination were found to have pulmonary nodules, and more than 90% of them did not show any symptoms. The diagnosis of pulmonary nodules in CT reports has brought panic to many people and seriously affected the quality of life. Our correct attitude towards pulmonary nodules should be scientific treatment and timely treatment.

What is a pulmonary nodule?

Pulmonary nodules are nodular shadows in lung parenchyma that do not belong to normal lung tissue. If the diameter is less than 3 cm, those with a diameter less than 1 cm are called small nodules, those with a diameter less than 3 mm are called micro nodules, and those with a diameter greater than 3 cm are called masses. Pulmonary nodules can be single or multiple. More than 80%-90% of pulmonary nodules are benign, such as benign tumors, pneumonia, tuberculosis, pulmonary arteriovenous malformation, old lesions and so on. Of course, some nodules are malignant, and a few benign pulmonary nodules may become malignant during follow-up.

What is a frosted glass nodule?

Ground glass nodules are also called ground glass shadows and ground glass nodules. , abbreviated as GGO or GGN. It is characterized by cloud-like shadows or nodules with slightly increased density, so it is called ground glass on CT. According to whether the nodules contain solid components, there are mixed ground glass nodules and pure ground glass nodules with solid components. According to pathological properties, ground glass nodules can be benign lesions such as focal fibrosis, inflammation or bleeding, precancerous lesions such as atypical adenoma and adenocarcinoma in situ, and malignant tumors such as minimally invasive adenocarcinoma and metastatic carcinoma.

What are the high-risk nodules of lung cancer?

High-risk nodules of lung cancer are lung cancer or lung cancer with high risk of transformation. For example, long-term smoking history, family history of lung cancer, definite malignant tumors in other organs of the body and other risk factors. The tumor diameter is ≥ 1.5 cm or 0.8- 1.5 cm, but it shows malignant CT signs such as lobulation, burr, pleural traction, bronchiolitis, vacuoles and eccentric thick-walled cavities, and some solid nodules with diameters greater than 0.8 cm are high-risk nodules. High-risk nodules need the comprehensive judgment of experienced radiologists, respiratory doctors or thoracic surgeons.

The more nodules, the higher the possibility of lung cancer.

The answer is no, there is no correlation between the number of lung nodules and the possibility of lung cancer. On the contrary, if there are multiple tiny nodules in the lung, the possibility of chronic inflammation is higher, but if there are multiple ground-glass nodules, attention should be paid to them.

What should I do if I find nodules in my lungs?

First of all, it should be clear that pulmonary nodules are not equal to lung cancer or early lung cancer, so there is no need to be overly anxious. Excessive panic is not desirable, but it is also not desirable to ignore them. Excessive panic will affect physiological and immune functions and induce diseases; Ignoring it will delay the illness and lose the best treatment opportunity. If pulmonary nodules are found, you should bring detailed imaging data and medical history to the hospital. You can do some further tests, such as detailed physical examination, tumor markers in blood and finding tumor cells in sputum. For example, patients with good economic conditions can also do PET/CT examination, such as high-risk patients, and lung biopsy under the guidance of fiberoptic bronchoscope and CT can make a definite diagnosis. Another sharp tool for diagnosis and treatment of pulmonary nodules is electromagnetic navigation bronchoscope. Its principle is similar to the navigation system we drive. In the complex pulmonary and bronchial network, we can accurately find the small nodules distributed in all corners. In addition to diagnosis, it can also be used as an accurate preoperative location to narrow the scope of surgical resection. What is more gratifying is that we can directly ablate high-risk nodules on the basis of accurate navigation, so that many patients can avoid the pain of surgery.

After detailed examination, patients generally have four choices:

1. Short-term review after oral antibiotics

Pneumonia or atypical pneumonia is characterized by many pulmonary nodules, and many patients disappear or become significantly smaller after short-term oral antibiotic treatment. Especially for the first time, ground-glass nodules were found, and antibiotic treatment was particularly important.

Step 2 follow up closely

Close follow-up is like a policeman staring at a suspect. It is necessary to finally determine the quality of each other through long-term observation. CT examination is the police, pulmonary nodules are the suspects. The method of judgment is to do CT examination again within a period of time (preferably thin-slice CT), and compare it with the previous CT to judge whether the size, density and position have changed. Benign nodules generally do not change in long-term follow-up, while malignant nodules can grow obviously in a short time. The specific follow-up interval should be comprehensively judged by the attending doctor according to the medical history and examination results, and the follow-up time should be shortened for high-risk nodules of lung cancer. If there is no growth within two years, most nodules are considered benign or low-grade malignant, but some nodules, such as ground glass nodules, should be followed up for a longer time.

Step 3: Surgical resection.

Surgical resection is the best radical treatment for malignant pulmonary nodules at present. Surgical treatment can be considered for patients with lung malignant tumor who can not be diagnosed clearly and are highly suspected. At present, the commonly used surgical method is thoracoscopic wedge resection of lung, which has the advantages of less trauma, faster healing and less impact on life. On the one hand, patients should not worry too much about surgical treatment, on the other hand, they still need to remember that most pulmonary nodules are benign and should not be overtreated because of excessive anxiety.

4. Ablation therapy

Compared with surgical treatment, ablation treatment is more minimally invasive, and diagnosis and treatment can be completed in one operation. Ablation only kills lung nodules and hardly affects normal lung function. At the same time, multiple pulmonary nodules located in different lobes can be treated at one time. Ablation therapy can be completed under the guidance of electromagnetic navigation bronchoscope or CT, and it can also achieve the curative effect of early lung cancer, but surgical resection is still the first choice for most malignant lung nodules. The following patients can consider ablation treatment: 1. Poor lung function, unable to tolerate surgical treatment; 2. I have had lung nodule resection, which will seriously affect my life; 3. Multiple pulmonary nodules cannot be completely removed by surgery at one time; 4. Patients with excessive fear and anxiety about surgery.

Illustration: the electromagnetic navigation bronchoscope accurately locates the pulmonary nodules, and the biopsy site is pathologically diagnosed as adenocarcinoma, and ablation treatment is carried out to achieve the cure effect.

How to treat the follow-up review correctly?

As mentioned above, most nodules are benign, so for most friends who find pulmonary nodules after seeing a doctor in the hospital, the answer is follow-up. When the doctor made the decision of follow-up, he explained that he was very relieved about this nodule at present, but in clinic, we found that follow-up brought great psychological burden to many patients and friends. Many people are anxiously waiting for the verdict of the next review, and even some friends count the days of the review every day or urgently review in advance. In fact, this kind of psychology is not desirable. The patient's friends should realize whether the pulmonary nodule finally becomes benign or a high probability event. Follow-up time is also determined by doctors according to clinical and imaging characteristics, which is a part of scientific diagnosis and treatment. What needs to be done during the intermission of follow-up is to forget the normal life span of nodules. Follow-up can save 40% patients from unnecessary surgery for the first time.

Will CT repeatedly radiate?

Follow-up is the main means to prevent and treat pulmonary nodules at present, but there are often patients in outpatient department who are worried about CT examination, mainly because of CT radiation. X-ray radiation exists in both CT and X-ray, and CT is slightly larger than X-ray radiation. Pregnant women and babies should try to avoid CT or X-ray examination. But it is no problem for adults to do it several times a year (10 or less). Patients' friends should adjust their mentality and cooperate with the examination.

How to choose all kinds of CT?

Low dose CT:

At present, the evidence shows that low-dose CT is an effective means to screen lung cancer, and its main advantage is that the radiation dose is small, which is about 1/4 of that of ordinary CT.

Ordinary CT plain scan:

Ordinary CT plain scan is the most widely used CT examination in clinic at present, which is equipped in most primary hospitals. The interval between plain CT scans is usually 8-10 mm. Low-dose CT and ordinary CT are commonly used for chest examination, which has the advantages of fast examination speed and low requirements for equipment, but the disadvantage is that the interval is too wide, which may lead to missed diagnosis of small nodules.

High resolution CT:

High-resolution CT refers to CT with a small layer spacing, generally less than 5 mm Compared with conventional CT, it has higher accuracy and stronger resolution, and can see the fine structures in the lung, which can be used for the follow-up of small pulmonary nodules, especially ground-glass nodules.

Thin-slice CT of pulmonary nodules:

Thin-slice CT of pulmonary nodules is a special examination item designed for pulmonary nodules in the radiology department of Zhongshan Hospital. The interval can be as low as 1mm, and the resolution of pulmonary nodules is higher. It can also accurately measure the density of nodules. Through three-dimensional reconstruction, we can accurately measure the volume of nodules, the relationship with blood vessels, the edge and so on, which is conducive to the judgment of benign and malignant, and can be used for the definite diagnosis and follow-up examination of pulmonary nodules. At present, it is the preferred examination method for pulmonary nodules.

Enhanced CT:

Generally speaking, pulmonary nodules do not need enhanced CT examination, but dynamic enhanced CT, especially dynamic enhanced CT of small nodules, has certain significance in differentiating isolated small nodules, which needs to be mastered by experienced respiratory doctors or thoracic surgeons.

PET/CT:

PET/CT can be mainly used for the diagnosis of high-risk solid nodules or partial solid nodules of lung cancer, and can also provide reference for selecting which nodules to biopsy when there are multiple nodules. The main principle is that the glucose uptake and metabolism of tumor cells are high, but the disadvantage is that it is expensive, so it is not recommended to be used as a routine follow-up for pulmonary nodules.