ARNOLD-Australasian Registry Network for Orphan Lung Disease

References

Quinton AE, Smoleniec JS. Congenital lobar emphysema – the disappearing chest mass: Antenatal ultrasound appearance. Ultrasound Obstet Gynecol 2001; 17: 169-171

Williams HK, Johnson KJ. Imaging of congenital cystic lung lesions. Pediatric Respiratory Reviews 2002; 3: 120-127

Mendeloff EN. Sequestrations, congenital cystadenomatoid malformations, and congenital lobar emphysema. Semin Thorac Cardiovascular Surg 2004; 16: 209-214

Ulku R, Onat S, Ozcelik C. Congenital lobar emphysema: Differential diagnosis and therapeutic approach. Pediatrics Internat 2008; 50: 658-661

Congenital malformations - Lobar emphysema

 

Leanne Gauld Royal Children’s Hospital, Mater Children’s Hospital, University of Queensland

Definition: Over-inflation of a pulmonary lobe due to partial or complete obstruction of a bronchus. Also known as Congenital Lobar Overinflation.

Causes: Extrinsic compression of bronchus – vascular anomalies, lymphadenopathy, teratoma, bronchogenic cyst.
Intrinsic obstruction of bronchus – defect in wall of bronchus (eg abnormal or absent cartilage), web, aspirated meconium, granulation tissue, bronchial torsion.
No clear cause of bronchus obstruction can be identified in 50% of cases.

Clinical Presentations: Males are affected more commonly than females.
The left upper lobe is the most commonly affected area, followed by the right middle lobe. Lower lobe involvement is rare.
Diagnosis by antenatal USS is now one of the most common presentations. Neonates may be well and asymptomatic at birth.
50% of cases present in the first 3 months of life, with the remainder presenting generally by 6 months of age. Presentation in the neonatal period can be with tachypnoea, respiratory distress, cyanosis, wheeze, cough or poor feeding. Breath sounds may be reduced over the affected area.
Not uncommonly, CLE presents as an incidental finding on CXR. Rarely it may present with infection of the involved lobe, mimicking abscess formation.

Investigations: Antenatal USS – CLE may be seen as a unilateral echogenic lesion. Lesions may disappear pre-natally, but postnatal imaging is required to exclude persistent CLE. CXR – lobar hyperinflation is present, often with splaying of the rib spaces over the affected lobe, and flattening of the diaphragm of the affected side. Mass effect with mediastinal shift may be evident. Flattening of the ipsilateral diaphragm may be present. CT chest - provides better definition of the lesion, and assists in differentiating from congenital cystic pulmonary airway malformations. It may demonstrate atelectasis of adjacent lung, and narrowing of the bronchus supplying the CLE may be evident. It may be useful in identifying associated vascular abnormalities. Echocardiogram – 14-40% are associated with other abnormalities, particularly cardiovascular abnormalities. Bronchoscopy – it has been suggested that bronchoscopy be used in all patients with conservative management planned, to exclude mucus plug or foreign body within the bronchus.

Treatment: There are numerous reports of spontaneous resolution of lung echogenicity in utero. Post-natal imaging is required to be certain of resolution. In neonates with respiratory distress, CLE should be differentiated from pneumothorax on CXR, so that intercostal drains can be avoided. Positive pressure ventilation may lead to further gas trapping, and worsening of respiratory distress. Lobectomy may be life-saving if severe respiratory distress is present. Lobectomy is generally indicated when there is significant mass effect, following infection within the lesion, or if there is recurrent episodes of respiratory distress. Many advocate lobectomy to minimize the risk of infection in the future, even in the absence of mass effect. Conservative management is the preferred course of action in those who are asymptomatic without midline shift.