Congenital lobar overinflation

Changed by Ayush Goel, 14 Oct 2014

Updates to Article Attributes

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Congenital lobar overinflation (CLO) (previosuly called congenital lobar emphysema) is a congenital lung abnormality that results in progressive overinflation of one or more lobes of a neonate lung. Various mechanisms have been postulated including an obstructive check valve mechanism at the bronchial level 2.

Epidemiology

Congenital lobar overinflation is more common in males (M:F = 3:1) 5

Clinical presentation

Patients typically present with respiratory distress, most commonly in the neonatal period, and usually within the first 6 months of life 5

Pathophysiology

In congenital lobar overinflation, a lobe (or more) become distended and may or may not have more alveoli. There are many presumed mechanisms for progressive overdistension of a lobe including obstruction, cartilage deficiency, dysplasia, and immaturity. Most cases are idiopathic. 

Associations

CLO may be associated with congenital heart defects such as:

Radiographic features

Interestingly there is quite a pronounced predilection for some lobes: 

  • left upper lobe: most common, 40-45%
  • right middle lobe: 30%
  • right upper lobe: 20% 
  • may involve more than a single lobe in 5%
  • much rarer in the lower lobes.

Therefore despite the left upper lobe being most commonly affected, the right hemithorax is the most common side to be affected 6.

Plain film -: chest radiograph
Immediate postpartum period 

The affected lobe tends to appear opaque and homogeneous because of fetal lung fluid or it may show a diffuse reticular pattern that represents distended lymphatic channels filled with fetal lung fluid.

Later findings
  • appears as an area of hyperlucency in the lung with a paucity of vessels
  • mass effect with mediastinal shift and hemidiaphragmatic depression
  • decubitus films lying on the affected side will show little or no change in lung volume
  • lateral film may demonstrate posterior displacement of the heart
CT chest
  • shows above features in greater detail
  • attenuation of vascular structures in affected lobe 4
  • may also show compressive atelectasis of neighbouring lobes

Treatment

Mildly symptomatic patients are usually followed up. A lobectomy can be considered in severe cases 3

Differential diagnosis

General imaging differential considerations include:

See also

  • -</ul><h4><strong>Radiographic features</strong></h4><p>Interestingly there is quite a pronounced predilection for some lobes : </p><ul>
  • -<li>left upper lobe: most common 40-45%</li>
  • +</ul><h4>Radiographic features</h4><p>Interestingly there is quite a pronounced predilection for some lobes: </p><ul>
  • +<li>left upper lobe: most common, 40-45%</li>
  • -</ul><p>Therefore despite the left upper lobe being most commonly affected, the right hemithorax is the most common side to be affected <sup>6</sup>.</p><h5>Plain film - chest radiograph</h5><h6>Immediate postpartum period </h6><p>The affected lobe tends to appear opaque and homogeneous because of fetal lung fluid or it may show a diffuse reticular pattern that represents distended lymphatic channels filled with fetal lung fluid.</p><h6>Later findings</h6><ul>
  • +</ul><p>Therefore despite the left upper lobe being most commonly affected, the right hemithorax is the most common side to be affected <sup>6</sup>.</p><h5>Plain film: chest radiograph</h5><h6>Immediate postpartum period </h6><p>The affected lobe tends to appear opaque and homogeneous because of fetal lung fluid or it may show a diffuse reticular pattern that represents distended lymphatic channels filled with fetal lung fluid.</p><h6>Later findings</h6><ul>
  • -</ul><h4>Treatment</h4><p>Mildly symptomatic patients are usually followed up. A lobectomy can be considered in severe cases <sup>3</sup>. </p><h4>Differential diagnosis</h4><p>General imaging differential considerations include</p><ul>
  • -<li><a href="/articles/congenital-cystic-adenomatoid-malformation">congenital cystic adenomatoid malformation (CCAM) / congenital pulmonary airway malformation (CPAM)</a></li>
  • +</ul><h4>Treatment</h4><p>Mildly symptomatic patients are usually followed up. A lobectomy can be considered in severe cases <sup>3</sup>. </p><h4>Differential diagnosis</h4><p>General imaging differential considerations include:</p><ul>
  • +<li><a href="/articles/congenital-cystic-adenomatoid-malformation">congenital cystic adenomatoid malformation (CCAM)/congenital pulmonary airway malformation (CPAM)</a></li>
  • -<a href="/articles/bronchial-atresia">bronchial atresia</a> - the distal to the atretic segment can have air trapping</li>
  • +<a href="/articles/bronchial-atresia">bronchial atresia</a>: the distal to the atretic segment can have air trapping</li>

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