Left superior vena cava as an incidental finding in a 70-year-old man referred for lymphoma staging.

Clinical History

This case concerns a 70-year-old man referred to our department for staging of a lymphoma. No anatomic defects were found on doing a cardiological examination.

Imaging Findings

A 70-year-old male patient, who had never been referred for a radiological examination, and who had been clinically diagnosed as having a lymphoma, established by doing a biochemical blood examination, was referred to our department for tumor staging. A chest CT was performed and the left superior vena cava was revealed. Cardiological examination was performed afterwards, together with cardiac ultrasonography (images not available) which revealed the drainage of the vessel.

Discussion

A persistent left SVC is thought to be the most common anomalous systemic condition to cardiac venous drainage. Its incidence is 0.3%, but it rises to 4.3% in patients with other congenital heart diseases. It is most frequently found together with a right-sided SVC. An aberrant vein often connects the two cavae across the anterior mediastinum. It may be associated with drainage into the left atrium, with an atrial septal defect, or with other lesions. As an isolated anomaly, it usually drains into the coronary sinus and causes no shunting of blood. The anomaly is due to persistence of the embryonic left anterior cardinal vein. Failure of formation of the left innominate vein in the fetus also coexists. A partial anomalous pulmonary venous return via the left vertical pulmonary vein, which empties into the left innominate vein, is to be distinguished from the persistent left superior vena cava, with which it may be confused. On plain radiographs, the left SVC may appear as a structure with a superadded density on the left side of the aorta. It appears to run vertically along the left superior mediastinum without obscuring the aortic knob. CT and MRI investigations can demonstrate the vessel which courses laterally to the aortic arch and anteriorly to the left hilum. In the majority of patients, the vessel enters the coronary sinus of the right atrium which gets enlarged. The left superior intercostal vein swings around the aorta and enters the left SVC. Echocardiographic findings of the left SVC include dilation of the coronary sinus without a right atrial enlargement. The dilated coronary sinus can protrude into the left atrium. The diagnosis is definitively confirmed on performing contrast echocardiography. By injecting a contrast medium into a left arm vein, the contrast will first appear in the coronary sinus, and it will later appear in the right atrium. Injection of an echo contrast into a right arm vein will opacify the right atrium without opacifying the coronary sinus.

Differential Diagnosis List

Final Diagnosis

Asymptomatic left superior vena cava.

URL:	https://www.eurorad.org/case/2676
DOI:	10.1594/EURORAD/CASE.2676
ISSN:	1563-4086