False aneurysm of the right internal mammary artery.

False aneurysms of the internal mammary artery are extremely rare. A case of false aneurysm of a branch of the right internal mammary artery after median sternotomy is reported. A large right-sided mediastinal mass was seen on the thoracic radiogram. A false aneurysm was suspected on CT-scan and confirmed by angiography. In the same setting percutaneous embolization was performed.