Complicated Lipomatous Hypertrophy of the Interatrial Septum

Lipomatous hypertrophy of the interatrial septum (LHIS) is a benign cardiac lesion characterized by excessive fat accumulation in the interatrial septum, often sparing the fossa ovalis. Although typically asymptomatic, severe cases may lead to hemodynamic compromise. We report 2 cases of exuberant symptomatic LHIS requiring surgical intervention. The first patient presented with dyspnea and upper extremity swelling, whereas the second had progressive exertional dyspnea. Multimodality imaging confirmed large interatrial septal masses leading to hemodynamic compromise. Both underwent successful surgical resection with histopathologic confirmation of benign adipose tissue. These cases highlight the importance of multimodality imaging in diagnosing and assessing LHIS in ambiguous and symptomatic cases. LHIS is an often underrecognized entity that can lead to significant hemodynamic complications. Comprehensive imaging and timely surgical intervention are key to optimal management in severe cases.