Congenital lobar overinflation
Updates to Article Attributes
Congenital lobar overinflation (CLO) (previosuly(previously 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 6six 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 radiographradiography
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:
- congenital cystic adenomatoid malformation (CCAM)/congenital pulmonary airway malformation (CPAM)
- pulmonary arterial hypoplasia
- pulmonary hypoplasia
- bronchial atresia: the distal to the atretic segment can have air trapping
See also
- differential for unilateral transradiant hemithorax
-<p><strong>Congenital lobar overinfl</strong><strong>ation (CLO) </strong>(previosuly called <strong>congenital lobar emphysema</strong>) is a <a href="/articles/congenital-lung-abnormality">congenital lung abnormality</a> 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 <sup>2</sup>.</p><h4>Epidemiology</h4><p>Congenital lobar overinflation is more common in males (M:F = 3:1) <sup>5</sup>. </p><h4>Clinical presentation</h4><p>Patients typically present with respiratory distress, most commonly in the neonatal period, and usually within the first 6 months of life <sup>5</sup>. </p><h4>Pathophysiology</h4><p>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. </p><h5>Associations</h5><p>CLO may be associated with <a href="/articles/congenital-cardiovascular-anomalies">congenital heart defects</a> such as:</p><ul>- +<p><strong>Congenital lobar overinfl</strong><strong>ation (CLO) </strong>(previously called <strong>congenital lobar emphysema</strong>) is a <a href="/articles/congenital-lung-abnormality">congenital lung abnormality</a> 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 <sup>2</sup>.</p><h4>Epidemiology</h4><p>Congenital lobar overinflation is more common in males (M:F = 3:1) <sup>5</sup>. </p><h4>Clinical presentation</h4><p>Patients typically present with respiratory distress, most commonly in the neonatal period, and usually within the first six months of life <sup>5</sup>. </p><h4>Pathophysiology</h4><p>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. </p><h5>Associations</h5><p>CLO may be associated with <a href="/articles/congenital-cardiovascular-anomalies">congenital heart defects</a> such as:</p><ul>
-<li><a href="/articles/patent-ductus-arteriosus">patent ductus arteriosus (PDA) </a></li>-<li><a href="/articles/tetralogy-of-fallot">tetralogy of Fallot </a></li>- +<li><a href="/articles/patent-ductus-arteriosus">patent ductus arteriosus (PDA)</a></li>
- +<li><a href="/articles/tetralogy-of-fallot">tetralogy of Fallot</a></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 radiography</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><h5>CT chest</h5><ul>- +</ul><h5>CT</h5><ul>
-</li></ul><p> </p>- +</li></ul>
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