Scimitar sign in the absence of anomalous pulmonary venous drainage: a case report

Scimitar syndrome consists of anomalous pulmonary vein drainage to the inferior vena cava. Its name derives from the image this anomalous pulmonary vein creates on a chest radiograph. We describe a case of normal venous pulmonary vein drainage that also presented the scimitar sign due to an aorto-collateral vessel.

A 15-month-old girl presented with mild dyspnoea and fever. Control chest X-ray showed an image of cardiac dextroposition, hypoplastic right lung, and the 'scimitar sign'. Although the transthoracic echocardiogram confirmed the initial suspicion of anomalous pulmonary venous drainage, the computed tomography (CT) scan showed normal right pulmonary veins connected to the left atrium and revealed that an aorto-collateral vessel caused the scimitar sign.

Although the patient had several typical alterations of the scimitar syndrome, the pulmonary venous connection was normal, and the scimitar sign was due to an aorto-collateral vessel. It might be difficult to describe venous pulmonary connections on the basis of echocardiography, so an angio CT scan proved to be a valuable tool in this scenario.