Chapter 52: Congenital Pulmonary Malformations

Congenital pulmonary malformations are relatively rare entities that can cause a wide variety of pulmonary findings in infants and children. In this chapter, we review the clinical and radiographic features of the most important malformations, including:

1. Congenital absence of the pulmonary vein

2. Tracheal bronchus

3. Bronchial cyst

4. Congenital lobar emphysema

5. Congenital cystic adenomatoid malformation

6. Pulmonary sequestration

7. Pulmonary agenesis

Congenital Absence of the Pulmonary Vein

Patient Story

A 5 year-old-girl is hospitalized for respiratory distress and hypoxemia. This is her third episode of right-sided pneumonia. She is thinly built; both height and weight are at the 25th percentile for age. Chest auscultation reveals fine alveolar crackles over the entire right lung without wheeze; the left lung is clear. Heart sounds are normal without a murmur. Her chest x-ray shows haziness of the entire right lung, with patchy opacity in the right lower zone; the left lung is normal. She is treated with parenteral antibiotics and improves. Blood and sputum cultures are negative. She is evaluated further for recurrent pneumonia. Serum immunoglobulin profile is normal. Sweat chloride is within normal limits. Chest CT scan with contrast shows Swiss cheese appearance of the entire right lung with cystic lucencies and septal thickening; the left lung is normal (Figure 52-1). Further cardiac evaluation with Echocardiography shows no intra-cardiac defect. Cardiac catheterization and pulmonary angiography reveal normal pulmonary artery anatomy, with isolated absence of the right main pulmonary vein. She is followed closely and her subsequent respiratory illnesses are treated early with antibiotics and bronchodilators. She remains asymptomatic with exercise tolerance and growth appropriate for age.

Introduction

Unilateral absence of the pulmonary vein is a rare congenital abnormality thought to be due to atresia of the pulmonary vein during development in the prenatal period. This results in abnormal venous drainage of the affected lung and significant ventilation perfusion mismatch.

Synonym

Congenital unilateral pulmonary vein agenesis.

Epidemiology

• Congenital absence of the pulmonary vein is a rare congenital anomaly, found in about 0.5 percent of autopsies performed in children.

• May occur as an isolated lesion or associated with other congenital cardiac defects in about 30 to 50 percent of cases.

• Mortality rate approaches 50 percent if untreated.

Etiology and Pathophysiology

• Rare developmental abnormality, in which there is absence of the right or left pulmonary vein or both.

• Thought ...