Atrial extension of mitral annular calcification mimicking intracardiac tumor

Liquefaction necrosis of mitral annular calcification occurs in 3% of autopsied cases. The liquified material can spread intramurally in various directions creating suspicious appearing mass lesions on chest x-ray or echocardiography. An incidential finding of an echogenic left atrial calcified mass in a 57-year-old woman was suspected to be an intracardiac tumor for which she underwent exploratory cardiotomy. Instead, culture-negative liquified pasty material was removed from the posterior left atrial wall adjacent to the calcified mitral annulus. This case illustrates that liquefaction necrosis of mitral annular calcification may spread to contiguous structures and masquerade as an intracardiac tumor. This relatively unknown aspect of mitral annular calcification should be considered in the differential diagnosis of echogenic left atrial mass lesions.