Double superior vena cava with a persistent left superior vena cava: an incidental finding during peripherally inserted central catheter placement.

We describe a case of double superior vena cava with a persistent left-sided superior vena cava discovered at the time of peripherally inserted central catheter (PICC) placement. The diagnosis was suggested by fluoroscopy and confirmed by venography. The relevance of the diagnosis with respect to PICC placement is discussed.