Mr. Dai is 40 years old and just reached the age where he can have his lungs CTed during his physical examination. The CT report clearly states “small nodules in the lungs”, what should I do? What should I do? Is it a benign nodule or a malignant tumor? The report also showed that the lung nodules were not in the lungs. The sudden result made Mr. Dai very panic and don’t know what to do. In fact, every year there are some people who find lung nodules in their health checkups, like Mr. Dai, most of them have no symptoms, neither coughing nor chest pain, but only a very slight discomfort occasionally. So is this situation important? How should it be treated? With this question, we interviewed Dr. Xiao Haibo, Deputy Chief Physician of Cardiothoracic Surgery Department of Shanghai Xinhua Hospital, and let him lead us to take a closer look at “small lung nodules”. What is a lung nodule? Lung cancer is the malignant tumor with the highest morbidity and mortality rate in the world, and due to the influence of smoking and air pollution, the number of lung cancer patients in China has increased rapidly in recent years. Since most lung cancer patients are already in the middle and late stages when they are diagnosed, the treatment effect is unsatisfactory and the long-term survival rate is low, improving the early diagnosis rate of lung cancer is a problem we urgently need to solve. Early lung cancer is often manifested as small lung nodules, so we can effectively screen out early lung cancer by timely detection and differential diagnosis of small lung nodules. Lung nodule is a soft tissue lesion with round shape, clear boundary and diameter less than or equal to 3cm in the lung parenchyma. Clinically, lesions less than or equal to 3 cm in the lung parenchyma are called nodules, lesions larger than 3 cm are called masses, while nodules smaller than 2 cm are called small nodules and nodules smaller than 5 mm are called micro nodules, which are defined in this way because the size of nodules has a certain degree of correlation with the benignity and malignancy of nodules. The reason is that nodules larger than 3 cm are more likely to be malignant, while smaller nodules are more likely to be benign. Do lung nodules mean lung cancer? Like Mr. Dai mentioned earlier, many people start to suspect that they have lung cancer once they find small nodules in their lungs on the medical checkup report, which makes them highly nervous and seriously affects their work and life. So, are these nodules really “bad”? In fact, the nature of lung nodules is diverse. Benign ones include inflammatory pseudotumor, malignant tumor, tuberculosis ball, granuloma, lung abscess, sclerosing hemangioma, fungal ball, etc. Pre-cancerous lesions such as atypical adenoma-like hyperplasia, and malignant ones may be primary lung cancer or lung metastasis. Knowing the above common causes of lung nodules, we can find out that small lung nodules are not necessarily lung cancer, and many benign diseases can also manifest as small nodules. Doctors mainly judge the benignity and malignancy of small nodules based on the imaging characteristics of small nodules and combined with dynamic changes, and the diagnostic accuracy rate of experienced doctors can reach over 90% at present. How do you distinguish between benign and malignant lung nodules? There are benign and malignant lung nodules, and the probability of malignancy is about 20%-40%, and the probability of malignancy increases significantly with age, so the lung nodules found on physical examination should never be ignored. According to clinical statistics, single nodules in the lung with a diameter greater than 25px account for more than half of the malignant lesions. Why are more and more people found to have lung nodules nowadays? The reason is that multi-row spiral CT has been commonly used in clinical treatment, health check-ups and disease screening. According to the statistics of more than 8000 cases of chest CT physical examination in Xinhua Hospital this year, the incidence of small lung nodules is up to about 20% or more. Since CT has the incomparable advantages of ordinary X-ray, high resolution and cross-sectional image, it can avoid the obstruction of ribs, spine and heart and clearly observe the lung tissue. Low-dose spiral CT can minimize radiation dose on the basis of providing imaging information, and is currently the best method for detecting pulmonary nodules. In order to improve the differential diagnosis of pulmonary nodules, CT examinations need to describe the location, size, density, shape, calcification, and the presence of lobulation, burr, and pleural depression at the edges of the nodule. Simply put, benign nodules have clear and smooth margins; whereas malignant nodules have irregular margins and appear to have short and thin burrs. For follow-up patients it is also necessary to compare with historical data to observe any changes in nodule morphology. Three-dimensional reconstruction of the lung nodules can also be performed with high-resolution CT if necessary to precisely calculate their density and volume. At present, Xinhua Hospital adopts the latest 256-row ultra-high resolution CT for 3D reconstruction of small lung nodules, which can evaluate the peripheral and infiltrative conditions in detail, probe the internal structure of nodules, assess the vascular growth status, calculate the volume multiplication time, and display small lung nodules more clearly and diagnose more clearly, so that early lung cancer can be invisible. Who should pay special attention to lung nodules? There are several categories of people who should not take it lightly when small shadows or nodules are found in the lungs during physical examination, and should actively receive regular examination and timely treatment: 1. people aged 40 or above; 2. people who are long-term smokers or passive smokers; 3. people who have been exposed to asbestos or radioactive elements; 4. people with previous history of tuberculosis or long-term chronic inflammation of the lungs; 5. people with personal or family history of tumors, especially lung cancer; 6. Those with family history; 6. Those with nodule size of 25px or more with burr-like, lobulated or pleural depression and other changes. What should I do if a lung nodule is found? With the increasing popularity of spiral CT, the detection rate of lung nodules is getting higher and higher. However, the cause of lung nodules is complex and the clinical presentation lacks specificity, so it is difficult for doctors to make a diagnosis. If small nodules are found in the lungs during physical examination, don’t worry first, it is not necessarily cancer; even if it is cancer, there is nothing to fear because most of them are extremely early stage cancer, which can be completely cured through timely and appropriate treatment. For patients with benign possible or uncharacterized pulmonary nodules, regular CT follow-up should be performed in combination with patients’ risk factors and dynamic observation for timely diagnosis. For patients with lung nodules whose morphological manifestations are highly suspicious of lung cancer, fiberoptic bronchoscopy or percutaneous lung nodule aspiration biopsy under the guidance of CT or B ultrasound can be taken according to the different locations of the lung nodules for pathological diagnosis and, if necessary, minimally invasive thoracoscopic surgery for resection. Clinically, some patients with pulmonary nodules sent for pathological examination after surgical removal of nodules have often developed local cancer, although the long-term postoperative results are very satisfactory due to timely treatment. Xinhua Hospital has routinely carried out preoperative CT-guided lung nodule localization combined with single-port thoracoscopic lung wedge and segmental lung resection and other minimally invasive treatment techniques. Patients with highly suspected malignant lung nodules are removed by minimally invasive surgery, with rapid frozen section sent on the spot and report issued in 30 minutes, and the scope of further surgical resection is decided according to the intraoperative pathological results. This makes surgery for pulmonary nodules more precise and less invasive, and the patient’s recovery time is greatly reduced. In conclusion, once a patient finds a small lung nodule, there is no need to be overly nervous, but not to be paralyzed either. Patients should actively consult with specialized thoracic surgeons and radiologists and other specialists to clarify the diagnosis and receive formal further examination or timely surgical treatment. Recently, Xinhua Hospital has taken the lead in jointly launching the “small lung nodules” specialist clinic (Monday afternoon and Thursday afternoon) with the Department of Thoracic Surgery and the Department of Radiology to provide patients with “one-stop” medical services. The doctor will determine the benignity and malignancy of the nodule according to the patient’s specific situation, and use fiberoptic bronchoscopy and CT localization puncture to help patients further clarify the diagnosis. The most important thing is to clarify the nature of the nodule at an early stage. For benign nodules, “close observation and long-term follow-up” is recommended, while if malignant nodules are suspected, “high vigilance and timely surgery” should be performed.