Spontaneous false aneurysm of left internal mammary artery.

A 15-year-old female patient presented with a history of a mass just medial to the left breast and fever. Her physical examination revealed upper extremity hypertension, delayed and diminished pulsations in the femoral arteries and a midsystolic murmur over the back. On catheterization of the aorta a 45 mmHg systolic pressure gradient was obtained across the coarctation segment. The selective left internal mammary artery angiography showed the relationship of distal portion with false aneurysm. A magnetic resonance scan showed a left parasternal mass extending anteriorly.