Congenital venolobar syndrome

Case contributed by Dr Rachael O'Rourke


Febrile illness with 'chest infection'. Cardiac malposition on CXR. Otherwise well. On examination: normal pulses and heart murmur indicating atrial shunt. Cardiac MRI confirmed venolobar syndrome. Later reimaged on CT.

Patient Data

Age: 7 years
Gender: Female



Features of scimitar syndrome with a hypoplastic right lung causing mediastinal shift to the right and elevation of the right hemidiaphragm, enlarged right-sided heart and scimitar vein in a retrocardiac position.


Dilated pulmonary trunk and right heart.
Large scimitar vein draining the entire right lung to the supradiaphragmatic IVC. 
Systemic artery arising from aorta at the level of the hiatus supplying a right lower lobe pulmonary segment, with venous drainage to the IVC representing an extralobar sequestration.

Horseshoe lung with a retrocardiac tongue of pulmonary parenchyma crossing the midline into the left hemithorax.

Extralobar sequestration with a pleural covering and containing atelectasis and foci of consolidation. 

In conclusion, congenital pulmonary venolobar syndrome in a young child with the following features:

  • scimitar syndrome
  • right heart and pulmonary trunk dilatation secondary to a left to right shunt
  • right lower lobe pulmonary extralobar sequestration
  • horseshoe lung

Case Discussion

Scimitar syndrome is a form of partial anomalous pulmonary venous drainage which can go undiagnosed for some time. The resulting left to right shunt can lead to pulmonary hypertension later in life. It is associated with sinus venosus type atrial septal defect (ASD), which results in a larger shunt.

Scimitar syndrome is also associated with pulmonary sequestration (commonly right lower lobe) and horseshoe lung. When these findings occur in the same patient, they are known as congenital pulmonary venolobar syndrome. Detection of the sequestration is important prior to corrective surgery to avoid morbidity and mortality caused by intraoperative injury to the systemic vessel(s).

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