Persistent Left Superior Vena Cava - Accidental Finding.

Background/aim: The presence of the superior left vena cava represents a rare anomaly of the thoracic venous system.

Case Report: An asymptomatic case of this type of anomaly, discovered as an accident during investigations for a different pathology (superior left pulmonary lobe tumor), is presented. A 56-year-old, heavy smoker was admitted in our clinic with a tumoral mass in the left superior pulmonary lobe discovered during a routine chest x-ray. Physical and clinical examination was normal. However, transthoracic echography noted a coronary sinus enlargement, which led to the suspicion of a thoracic venous anomaly. Contrast chest computed tomography pointed out a venous anomaly at the level of the left hemithorax originating from the cervical region, crossing the aortic arch and draining in the coronary sinus. During the examination, contrast substance was not detected in the right superior vena cava, either early or late during the computed tomography. During surgery the presence of a persistent left superior vena cava was observed, coming from the cervical region, crossing lateral to the aortic arch and draining in the coronary sinus.

Conclusion: The presence of an enlarged coronary sinus should warn the surgeon about the possibility of a thoracic venous anomaly. Identifying a persistent left superior vena cava is important due to its clinical implications, especially during certain procedures such as mounting central venous lines, cardiac cannulation or implantation of cardiac stimulators.