Lipomatous hypertrophy of the interatrial septum: a case report

Lipomatous hypertrophy of the interatrial septum is generally a benign disorder characterized by lipid accumulation in the interatrial septum. A 56-year-old asymptomatic woman with a history of hypertension and hyperlipidemia was referred to echocardiographic examination. Transthoracic echocardiography showed left ventricular hypertrophy, normal left ventricular systolic function, and left ventricular relaxation disturbance. The apical four-chamber view showed a hyperechogenic mass in the interatrial septum. Lipomatous hypertrophy was suspected and transesophageal echocardiography was performed. A dumbbell-shaped hypertrophy of 22 mm thickness was noted in the interatrial septum, which did not involve the fossa ovalis. There was no decrease in flow velocities of the superior and inferior vena cava nor a flow disturbance in the pulmonary veins. Cardiac magnetic resonance imaging showed lipomatosis and thickening in the interatrial septum and subepicardial region.