bubble_chart Overview

Congenital pulmonary cystic sexually transmitted disease is a relatively rare congenital pulmonary developmental anomaly. The pathological classification and nomenclature are quite confusing and inconsistent. Previously, it was collectively referred to as congenital pulmonary cysts, but now it is more commonly termed congenital pulmonary cystic sexually transmitted disease, including bronchogenic cysts (pulmonary cysts), alveolar cysts, lobar emphysema (pulmonary bullae), cystic adenomatoid malformation, and congenital cystic bronchiectasis.

bubble_chart Etiology

During the embryonic development period, it is caused by abnormal budding or branching development of the trachea and bronchi. The lesions can occur at different locations of bronchial branches and exhibit various developmental stages. The cysts are often multilocular but can also be unilocular. The cyst walls usually have the structure of small bronchial walls, with an inner layer of ciliated columnar epithelium and scattered small pieces of cartilage visible in the outer layer. Smooth muscle bundles and fibrous tissue can be observed within the wall. Different epithelial cells can be seen in the inner layer of the cystic lesion structure, including columnar, cuboidal, and round epithelial cells, indicating varying degrees of incomplete development in the branching of the bronchial tree. Some have columnar cells that secrete mucus, and the lumen is filled with mucus.

bubble_chart Clinical Manifestations

Small bronchial cysts do not present symptoms clinically and are only discovered during chest X-ray examinations or autopsies. Once the cyst {|###|} communicates with the small bronchi, causing secondary infections or producing tension pneumatoceles, hydroceles, hydropneumatoceles, or tension pneumothorax that compress lung tissue, the heart, mediastinum, and tracheal displacement, symptoms may appear.

(1) Infancy and early childhood: Tension bronchogenic cysts, lobar emphysema, and pulmonary bullae are more common. Clinically, intrathoracic tension hypertension symptoms often manifest as rapid breathing, cyanosis, or respiratory distress. Physical examination reveals tracheal displacement to the contralateral side, tympanic percussion on the affected side, and diminished or absent breath sounds. Chest X-rays show lung collapse due to the cyst {|###|} on the affected side, mediastinal and tracheal displacement, and may also reveal mediastinal herniation and ipsilateral lung collapse. The condition is critical, and delayed diagnosis and treatment can lead to death from respiratory failure.

(2) Childhood: Bronchogenic cysts are more common. Clinical manifestations include recurrent lung infections. Patients often seek medical attention due to fever, cough, and chest pain. Symptoms resemble bronchopneumonia.

(3) Adulthood: Acquired secondary pulmonary bullae and bronchogenic cysts are more common. Clinical symptoms arise from secondary infections, such as fever, cough, purulent sputum, hemoptysis, chest tightness, asthma-like episodes, exertional dyspnea, and recurrent pneumothorax. Differentiation is required from lung abscess, empyema, bronchiectasis, pulmonary subcutaneous node cavities, and lung tumors.

Congenital bronchogenic cysts: Commonly seen in pediatric cases, the cysts are located in the lung interstitium or mediastinum. Approximately 70% are intrapulmonary, while 30% are mediastinal. As the cysts can be single or multiple and contain varying amounts of gas or fluid, chest X-rays may show different presentations:

1. Single fluid- or air-filled cyst: Most common, with cysts of varying sizes, showing round thin-walled cysts with fluid levels. The characteristic of such cysts is their thin walls, with no inflammatory infiltration or significant fibrosis in the adjacent lung tissue. Differentiation is required from lung abscess, pulmonary subcutaneous node cavities, and pulmonary hydatid cysts. On X-ray, lung abscesses have thicker walls with obvious surrounding inflammation, while pulmonary subcutaneous node cavities have a longer history and surrounding subcutaneous node satellite lesions. Pulmonary hydatid cysts have epidemiological regional characteristics, life and occupational history, blood tests, and intradermal tests aiding in differentiation.

2. Single air-filled cyst: Chest X-rays show an air-filled cyst in the affected lung. A giant air-filled cyst can occupy one side of the thoracic cavity, compressing the lung, trachea, mediastinum, and heart, requiring differentiation from pneumothorax. The hallmark of pneumothorax is lung collapse toward the hilum, while the air in the cyst is within the lung. Careful observation often reveals lung tissue at the apex and costophrenic angle.

3. Multiple air-filled cysts: Also relatively common clinically, chest X-rays show multiple air-filled cysts of varying sizes and irregular edges, requiring differentiation from multiple pulmonary bullae. Especially in children, pulmonary bullae are often accompanied by pneumonia, characterized on X-ray by translucent round thin-walled bullae and their variability in size, number, and shape. Short-term follow-up often reveals significant changes, sometimes rapid enlargement or rupture leading to pneumothorax. Once lung inflammation subsides, bullae may shrink or disappear on their own.

4. Multiple fluid- and air-filled cysts: Chest X-rays show multiple fluid- and air-filled cavities of varying sizes. Particularly when the lesion is on the left side, differentiation from congenital diaphragmatic hernia is required. The latter can also present with multiple fluid levels. If necessary, oral iodized oil or dilute barium examination can be performed. If contrast enters the gastrointestinal tract within the thoracic cavity, it indicates diaphragmatic hernia.

bubble_chart Treatment Measures

Generally, when the diagnosis is clear and there is no acute inflammation, early surgery is recommended. Because cysts are prone to secondary infections, drug treatment not only fails to cure them but may also lead to antagonism. Repeated infections can cause inflammatory reactions around the cyst wall, resulting in extensive adhesions of the pleura, making surgery more difficult and increasing the risk of complications. Young age is not an absolute contraindication for surgery. Especially in cases of hypoxia, cyanosis, or respiratory distress, early surgery—even emergency surgery—is necessary to save the patient's life.

The surgical approach should be determined based on the location, size, and infection status of the lesion: for uninfected cysts isolated beneath the pleura, simple cystectomy may be performed; for cysts confined to the lung margin, wedge resection of the lung may be appropriate; for cysts with surrounding adhesions due to infection or adjacent bronchiectasis, lobectomy or pneumonectomy may be required. In cases of bilateral sexually transmitted disease lesions, the more severely affected side should be operated on first, provided surgery is indicated. In children, the principle is to preserve as much normal lung tissue as possible.

When clinically suspecting this condition, thoracentesis should be avoided to prevent pleural infection or tension pneumothorax. Only in rare cases, where severe respiratory distress, cyanosis, or hypoxia is present and emergency surgery is not feasible, may cyst puncture and drainage be performed as a temporary measure to relieve symptoms before surgery. Generally, resection of the affected cyst or lobe yields a good prognosis.

For adult patients with excessive sputum preoperatively, double-lumen endotracheal tube anesthesia should be used during surgery to prevent sputum reflux into the contralateral side. In children, a low prone position with the affected side down may be adopted for thoracotomy, and the bronchus of the diseased lung should be ligated first upon entering the chest.

If the lesion is too extensive, pulmonary function is severely compromised, or there are coexisting severe organic diseases of the heart, liver, or kidneys, surgery is contraindicated.