A case of lipomatous hypertrophy of the interatrial septum detected via transthoracic 2-dimensional echocardiography.

A 71-year-old woman underwent echocardiography for the evaluation of hypertensive heart disease. A 2-dimensional echocardiogram revealed an abnormal mass that protruded into the left atrium from the atrial septal side of the left atrial wall. Microscopic examination of the surgical specimen disclosed a mixture of normal-appearing fat, vesicular fat, and hypertrophied myocytes, and degenerated cardiac tissue with foci of necrotic fat tissue, consistent with lipomatous hypertrophy. Although lipomatous hypertrophy of the interatrial septum is rare, this little-known entity should be included in the differential consideration of the left atrial mass detected via echocardiographic examination, particularly in both obese and elderly patients.