Left anomalous unilateral single pulmonary vein

A 45-year-old female patient presenting with dyspnea, tachypnea, and tachycardia referred to our radiology department to exclude pulmonary embolism.

CT pulmonary angiography was performed by injection of 80 ml of non-ionic contrast (Omnipaque, iodine conc. 350) introduced by a pump injector at rate of 4 ml/sec through cannula inserted in the left antecubital vein and pulmonary embolism was excluded. Incidentally discovered single dilated left side pulmonary vein connected to the left atrium draining the left upper and lower lung lobes.

Congenital anom­alies of the pulmonary veins are classified into anomalies in the number or diameter of the veins, anomalies in the drainage pattern or anomalous connection to a pulmonary artery [1].

Anomalous unilateral single pulmonary vein (AUSPV) is considered an anomaly in the number of the pulmonary veins in which an abnor­mal solitary pulmonary vein joins one side of the left atrium after draining the pulmonary veins from one lung. The term meandering pulmonary vein has also been used to describe this condition [2].

It has been speculated that this anomaly occurs during the primitive embryological development of the pulmonary veins if one of the pulmonary veins undergo atresia before pulmonary segmentation has occurred [3].

As the anomalous vein drains into the left atrium, there’s no right to left shunt and therefore, the patients are usually asymptomatic, with the anomaly being detected incidentally in most cases [3].

AUSPV is a very rare anomaly; with only few case reports described in the literature [4].

AUSPV is more frequent on the right side, however, it may be found bilaterally [4].

An AUSPV may be associated with other pulmonary anomalies including partial anomalous pulmonary venous drainage or pulmonary hypoplasia [4].

The diagnosis can be easily reached using CT which allows clear depiction of the anomalous vein [4].

Since there is no vascular shunt, AUSPV does not require treat­ment, hence, it is im­portant to differentiate this anomaly from others that may need treatment [2].

Written informed patient consent for publication has been obtained.