Cardiac Calcified Amorphous Tumor in a Newborn.

Calcified amorphous tumors (CATs) of the heart are rare, nonneoplastic, intracavitary lesions, previously thought of as pseudotumors, hamartomas, or calcified thrombi, only reported in few adults in the available literature. This report describes a case of a pedunculated oscillating CAT arising from the left atrial appendage that prolapses through the mitral valve and causes severe mitral regurgitation in a newborn. This is the only case of cardiac CAT described in a neonate.