Left ventricular outflow obstruction produced by a pedunculated fibroma in a newborn: clinical, angiographic, echocardiographic and surgical observations.

An unusual case of a one-day-old infant with significant left ventricular outflow obstruction produced by a pedunculated fibroma is described. The clinical findings were indistinguishable from severe valvular or subvalvular aortic stenosis. The tumor was difficult to detect by echocardiography. It produced an echo-free widening of the left ventricular outflow tract. Left ventricular cineangiography clearly demonstrated a mobile mass beneath the aortic valve.