Congenital pulmonary cyst in children
Introduction
Introduction to congenital pulmonary cyst in children Congenital pulmonary cyst (congenital pulmonary cyst) is a relatively common pulmonary dysplasia. Single or multiple cysts appear in the diseased lung tissue, which may involve one or several lung lobes. The clinical manifestations are quite inconsistent, some may be completely asymptomatic, and some may cause severe compression symptoms due to tension gas accumulation in the cyst. basic knowledge The proportion of illness: 0.002% Susceptible people: children Mode of infection: non-infectious Complications: pneumothorax
Cause
Causes of congenital pulmonary cyst in children
(1) Causes of the disease
The etiology is not fully understood. Some people think that it is due to abnormal branching during the development of embryonic lung buds. The distal end forms epithelial cell nests, and then gradually differentiates to form cysts. The lumen of the cysts is strip-like, and the bronchus is blocked. There is only partial communication, and another explanation is that the formation of pulmonary cysts is caused by congenital atelectasis, which causes the normal arrangement of lung structure and epithelial cells in the embryonic stage to be disordered.
(two) pathogenesis
The mechanism of the lung is generally considered to be that the bronchus is separated from the main bronchial bud during embryonic development, and the mucus secreted by the distal bronchus accumulates. The bronchogenic cyst is mostly located in the mediastinum, and the alveolar-derived pulmonary cyst is mostly located in the lung. The surrounding part is located in the lung parenchyma. The congenital pulmonary cyst can be single or multiple, and can occur in one lung lobe or several lung lobe. If one or one lobe lung tissue is occupied by most or all of the multiple cystic tissues, It is called polycystic lung, visual observation, the size of the cyst cavity can be different, can be single-atrial or multi-atrial, the surface of the cyst is smooth, the wall is thin, contains mucus or air mucus, histological observation, outside the cyst The layer consists of connective tissue, elastic tissue and smooth muscle fibers. The lumen contains sparse cartilage tissue. The inner layer of the cyst wall is mainly composed of columnar epithelial cells or pseudostratified ciliated epithelial cells, which also contain mucous gland tissue. The secretion of mucus is injected into the cyst, and the blood supply to the lung cyst is the same as that of normal lung tissue, which is derived from the pulmonary artery and the bronchial artery. This is different from lung isolation and, in addition, due to Cyst does not participate in respiratory activity, so the cyst wall can not see the pigmentation of the carbon. When the mucus in the cyst is excessively retained, or secondary purulent infection, the cyst is easy to penetrate with the bronchus, often forming a one-way valve-like ventilation. Therefore, the pressure in the cyst is continuously increased to form a tension balloon.
Some people think that if more bronchial epithelial cells are found in the cyst wall, it means that the cyst is from the bronchus, called bronchogenic cyst; if the cyst wall is mainly composed of squamous epithelial cells, it is called pulmonary cyst, but in most In the case, the wall layer of the cyst contains the above two kinds of cells, so it is difficult to explain that the pathological basis of the two is different. When the cyst is complicated by infection, the original cell structure of the cyst wall is changed due to inflammatory cell infiltration, chronic lung The squamous epithelial cell layer may also appear on the wall of the abscess, so it is difficult to determine the nature and origin of the cyst by histological examination alone.
Prevention
Pediatric congenital pulmonary cyst prevention
There are currently no effective preventive measures. This disease is congenital pulmonary dysplasia, the same as other methods of prevention of congenital diseases. After a clear diagnosis, attention should be paid to prevention of infection and active treatment. Asymptomatic infants and young children can be closely observed for months or years after elective surgery to increase the tolerance of surgery. Operate as soon as possible after controlling the infection. In order to avoid secondary infection and various complications, it is difficult to operate.
Complication
Pediatric congenital pulmonary cyst complications Complications
In severe cases, it causes respiratory and circulatory failure. The cause of this phenomenon is mainly related to the formation of tension-induced balloon swelling in the cystic cavity and the bronchus. Larger cysts have secondary infections, such as violent crying, trauma, etc., which can lead to tension pneumothorax. Pulmonary cysts have no gas exchange function. Large cysts can compress lung tissue, causing gas exchange obstacles in the lungs. In severe cases, pulmonary artery pressure can be increased and the burden on the heart can be increased. Long-term repeated infections may lead to adhesion of surrounding tissues, affecting lung function, increasing the difficulty of surgery and affecting postoperative recovery. Bleeding caused by destruction of the cystic wall of the lung cyst, perforation, causing pneumothorax, hemothorax. It has been reported in the literature that pulmonary cysts may be malignant.
Symptom
Congenital pulmonary cyst symptoms in children Common symptoms Low heat dysphagia, increased heart rate, dry cough cyst, respiratory distress syndrome, hemoptysis, respiratory dysfunction, dyspnea
The clinical manifestations of congenital pulmonary cysts can be very different. According to the size and number of cysts, the degree of influence on adjacent organs, the presence or absence of complications such as infection and rupture, the performance is different, mainly for oppression and infection symptoms. The cyst can be free of any symptoms. It is only found on X-ray examination. Different cysts appear when there are more cysts than secondary infections or sudden enlargement to compress surrounding tissues. For example, compression of the bronchi can produce wheezing, dry cough and varying degrees. Difficulty breathing, even cyanosis, oppression of the esophagus can cause difficulty swallowing, fever, cough, cough and even hemoptysis can occur when infected, small cysts can have no abnormal signs during physical examination, the larger ones percussion local dullness or real sound, Breathing sounds are weakened or disappeared. Tension-containing balloon swelling is more common in newborns and infants. It has increased breathing and heart rate, respiratory distress, wheezing and cyanosis, percussion of unvoiced or drum sounds, respiratory sounds disappear, with mediastinum and heart shift. It is easy to combine with tension pneumothorax. When it is chronically infected, it is characterized by repeated cough, cough and low fever.
Examine
Examination of congenital pulmonary cysts in children
Blood gas analysis has hypoxemia. In the case of secondary infection, peripheral blood has increased white blood cells and increased neutrophils.
1. X-ray examination: The solitary fluid cyst on the chest radiograph has a clear and dense circular shadow. The isolated balloon contains a circular or elliptical thin wall. If the lung cyst is located in the posterior mediastinum, it appears. Esophageal compression symptoms, need to check the barium meal when dysphagia, to understand the relationship between the tumor and the esophagus, and can identify sputum.
2. Bronchography: The extent and location of cyst lesions can be determined.
3. CT: It is helpful to determine the location of the cyst, the size and the relationship between adjacent organs. The identification of bullous cyst and pneumothorax can be used for enhanced CT scan. The former can be seen in pulmonary vascular shadow.
4. Angiography: Helps identify isolated lungs.
5. B-ultrasound: For the differentiation of lung, pleural lesions, gas, cystic, solid lesions have a certain role, but for lung abscess, cystic adenoma, etc. need further identification.
6. Fiberoptic bronchoscopy: In the presence of hemoptysis, fiberoptic bronchoscopy can understand the condition of the mucosa, identify the bleeding site, except for bronchial tumors.
Diagnosis
Diagnosis and diagnosis of congenital pulmonary cyst in children
The history of recurrent pulmonary infection and X-ray examination are the main points of diagnosis. The clinical manifestations of pulmonary cysts are often non-specific. The diagnosis of this disease mainly relies on X-ray examination. The single-shot closed pulmonary cyst shows a circle under the X-ray. Shape or round shape of the solid, uniform density, clear edges, surrounding tissue generally no obvious inflammatory infiltration, extrapulmonary cysts are located above the anterior mediastinum, mostly single, oppression of the trachea or main bronchus, can cause Paroxysmal dry cough, difficulty breathing, can cause excessive inflation of the lung tissue, mediastinal shift, etc., diagnosis depends on bronchoscopy and bronchography, combined with chest X-ray examination, can confirm the diagnosis.
