Author Duncan Keegan, M.D.1,2, Gregory Burg, M.D.1,2 1Division of Pulmonary Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH. 2Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH.
Case
A former full-term 3-month-old with pectus excavatum presented to her
primary pediatrician with worsening tachypnea and poor weight gain. She
was referred to the emergency department after the chest radiograph
shown below was obtained. On initial evaluation she had normal
saturations on room air, but her respiratory rate was in the 70s and she
had subcostal and suprasternal retractions on exam. Auscultation
revealed diminished left sided aeration, but no wheezing, crackles, or
other localized findings.
Figure 1: Supine Chest X-Ray
Question
What is the diagnosis?
A. Foreign body aspiration B. Congenital lobar emphysema C. Congenital pulmonary airway malformation D. Obstructive bronchogenic cyst E. Poland Syndrome
Answer
B. Congenital lobar emphysema
Discussion
The answer is congenital lobar emphysema (CLE). The chest X-ray
demonstrates classic findings of unilateral hyperlucency caused by
overdistention of the affected lobe, mediastinal shift, and atelectasis
of the contralateral lung (1).The findings seen here were also
demonstrated on CT scan (below) which showed focal narrowing of the left
upper lobe bronchus near its origin, with left lung overinflation
resulting in rightward shift of the mediastinum. The infant in this case
underwent flexible bronchoscopy to rule out a foreign body or another
obstructive lesion prior to having a successful lobectomy. She recovered
well and had resolution of tachypnea as well as improved weight gain.
CLE is a rare congenital lung malformation in which partial bronchial
obstruction results in hyperinflation of one or more pulmonary lobes
(1,2). CLE is also referred to as congenital lobar hyperinflation,
infantile lobar emphysema, congenital large hyperlucent lobe,
polyalveolar lobe, and congenital alveolar overdistention. Typical
presentation is characterized by progressive tachypnea, respiratory
distress, wheeze, recurrent respiratory infections, and failure to
thrive (1,2). The diagnosis of CLE is difficult prenatally, but almost
all cases are diagnosed prior to 6 months of age with 50% diagnosed in
the immediate neonatal period (1-4). Though rare, presentation in adults
has been described (5). Outside of the neonatal period insidious onset
of symptoms is the norm and some patients may even remain asymptomatic
(3). The left upper lobe is most commonly affected followed by the
right middle lobe and right upper lobe; involvement of lower lobes is
uncommon (1-3). The etiology is variable, and cases can generally be
classified as resulting from internal bronchial obstruction, external
bronchial obstruction, or a deficiency of the bronchial cartilage (1-3).
About 50% of cases have no identifiable cause (2). CT or MRI with or
without bronchoscopy is often used to confirm the diagnosis after CLE is
suspected based upon chest X-ray. Treatment is based upon severity of
clinical symptoms and consists of either surgical lobectomy or expectant
management for asymptomatic and minimally symptomatic patients (1-4).
Except in the rare and unique case of polyalveolar lobe which has true
alveolar hyperplasia, histological examination shows normal radial
alveolar counts with prominent airspace enlargement and no tissue damage
as might be seen in acquired emphysema (1,2).
Figure 2: Coronal CT scanFigure 3: Axial CT Scan
References
Abel, Robin M, et al. “Congenital Lung Disease.” Kendig and Chernick's Disorders of the Respiratory Tract in Children, 8th ed., Elsevier, 2012, pp. 317–357.
Demir, Omer Faruk et al. “Congenital lobar emphysema: diagnosis and treatment options.” International journal of chronic obstructive pulmonary diseasevol. 14 921-928. 1 May. 2019, doi:10.2147/COPD.S170581
Kunisaki, Shaun M et al. “Current operative management of congenital
lobar emphysema in children: A report from the Midwest Pediatric Surgery
Consortium.” Journal of pediatric surgeryvol. 54,6 (2019): 1138-1142. doi:10.1016/j.jpedsurg.2019.02.043
Abdel-Bary, Mohamed et al. “Clinical and surgical aspects of
congenital lobar over-inflation: a single center retrospective study.” Journal of cardiothoracic surgeryvol. 15,1 102. 19 May. 2020, doi:10.1186/s13019-020-01145-8
Shen, Cheng, and Guowei Che. “Congenital Lobar Emphysema in an Elderly Patient.” American journal of respiratory and critical care medicine, 10.1164/rccm.202004-1337IM. 8 Sep. 2020, doi:10.1164/rccm.202004-1337IM
