Complete or partial underdevelopment of the organ
The most severe forms of underdevelopment include aplasia (or aplasia / agenesia pulmonia). This pathology is extremely rare and is characterized by the complete absence of lung tissue. It often occurs not in isolation, but in combination with other severe anomalies, particularly esophageal atresia or congenital diaphragmatic hernia. The prognosis for this condition is extremely unfavorable: it is very frequently incompatible with life, and possible management is strictly symptomatic.
A more common variant is pulmonary hypoplasia (hypoplasia pulmonis), which essentially involves the underdevelopment of the bronchopulmonary structure. Congenital polycystic lung disease is considered a special form of this malformation.
The clinical presentation of hypoplasia includes:
- Chronic, frequently recurring bronchitis and pneumonia.
- Visual retraction of the chest wall on the affected side.
During physical examination, the physician may detect characteristic dullness on percussion. Instrumental diagnostics rely on radiography, which reveals opacification of the entire lung field or a part of it, as well as bronchography, which clearly visualizes cystic dilatation of the bronchi. The main method of treatment is surgical resection of the affected underdeveloped segments.
Congenital lobar emphysema
Congenital lobar emphysema (emphysema pulmonum congenitum lobare) is a developmental anomaly localized in the area of the supplying bronchus and its branches.
The pathogenesis is based on ventilation impairment: the affected lung lobe is constantly in a severely hyperinflated state and does not collapse at all during expiration. As a result, the expanded lung tissue begins to physically compress adjacent, healthy lobes. Gradually, a pronounced mediastinal shift toward the healthy side occurs.
Clinically, the disease manifests with signs of respiratory failure, specifically hypoxia and severe dyspnea. On the radiograph, the pathology appears as an area of increased radiolucency in the projection of the hyperinflated lobe, accompanied by a mediastinal shift. The only effective treatment method is surgery, which involves the removal of the expanded and non-functioning lung lobe.
True lung cysts
The appearance of true cysts in the lung tissue is directly related to impaired embryonic development of the respiratory apparatus. The cysts themselves may be asymptomatic, but clinical manifestations appear when the disease is complicated.
The main complications include:
- Suppuration of the cyst contents.
- Compression of adjacent, normally functioning lung lobes.
- Sudden rupture of the cystic cavity followed by the development of pneumothorax.
Treatment of complicated cysts is strictly surgical: resection of the affected lung tissue along with the cyst itself is performed, most commonly as a lobectomy.
Pulmonary sequestration
A special type of malformation is pulmonary sequestration (sequestratio pulmonalis). In terms of localization, it is most frequently intralobular.
The mechanism of formation (pathogenesis) of this anomaly is unique. An area forms within the lung tissue that develops completely isolated from the general bronchial system. At the same time, this area receives an additional, independent blood supply via an aberrant artery originating directly from the aorta. Because this separated area is tightly located inside the lobe, its physical separation from the surrounding healthy lung tissue is technically impossible.
The main danger of pulmonary sequestration lies in the high risk of suppuration of the sequestered area. Treatment requires a lobectomy, with a crucial step of the operation being the reliable and mandatory ligation of the feeding aberrant vessel originating from the aorta.
Briefly: answers to topical questions
What is the difference between intralobular and extralobular pulmonary sequestration?
Intralobular (intralobar) sequestration is located within the lobe, and its separation from the lung tissue is impossible; venous drainage occurs into the pulmonary veins. In extralobular (extralobar) sequestration, venous drainage occurs into the systemic venous system.
With which diseases is it necessary to perform differential diagnosis of a suppurated lung cyst?
A suppurated lung cyst must be differentiated from other suppurative diseases that cause infectious destruction of lung tissue.
As part of the differential diagnosis, the following pathologies are ruled out:
- Lung abscess — a localized process with the formation of a purulent cavity bounded by a pyogenic capsule.
- Lung gangrene — a rapidly progressing purulent-putrefactive tissue necrosis without a tendency toward localization.
- Bronchiectasis — a chronic process with irreversible bronchial dilatation and impairment of their drainage function.
- Absceding pneumonia — a specific stage or form of pulmonary destruction.
To quickly remember the essence of pulmonary sequestration, think of the word "sequestration" as a "secret isolated agent": it lives inside the lobe, does not communicate with the general bronchial network, and is fed by its own "illegal" (aberrant) vessel coming directly from the aorta.
Class and exam questions
What sound is determined upon percussion of a patient with pulmonary hypoplasia?
Physical examination of a patient with pulmonary hypoplasia will reveal dullness on percussion over the affected area.
What is the main danger of pulmonary sequestration?
The most formidable complication of this malformation is severe suppuration of the sequestered (isolated developing) area of lung tissue.
Why does congenital lobar emphysema occur?
The pathology is caused by a developmental defect of the supplying bronchus, due to which the lung lobe does not collapse upon expiration, remains hyperinflated, and compresses adjacent structures.
What are the radiological signs of pulmonary hypoplasia?
On the radiograph in hypoplasia, opacification of the entire lung field or its affected part is determined.
What else to study on this topic
- Technique of performing lobectomy for true lung cysts
- Features of aberrant vessel ligation in pulmonary sequestration
- Specifics of performing bronchography to confirm polycystic lung disease
- Pathogenesis of mediastinal shift in lobar emphysema
- Associated developmental anomalies: diaphragmatic hernia and esophageal atresia
Master the entire topic in the "General Surgery" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Lung Malformations" and 3,335 other subject pages
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 70 video lessons on the subject
Other topics in "CHAPTER 16. CONGENITAL MALFORMATIONS"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.