Lipomatous hypertrophy of the interatrial septum: a pathological and clinical approach.

Lipomatous hypertrophy of the interatrial septum (LHIS) is a rare benign disorder that is characterized by accumulation and deposition of fat in the interatrial septum. Its etiology is still unknown, despite the theories that have been suggested. It usually occurs in older, obese people with a higher incidence in women. In most cases, it remains asymptomatic, thus its diagnosis is rarely made during a person's lifetime and it is made incidentally or during autopsy. LHIS can cause atrial arrhythmias, obstructive flow symptoms and sometimes death. The diagnosis of LHIS can be made by the use of imaging techniques, with the best results given by multislice-CT (MSCT) scanning. Surgical intervention is usually avoided and the best management is early diagnosis, reassurance and inactivity. However, in cases of severe superior vena cava obstruction or intractable rhythm disturbance, surgical excision is performed together with reconstruction of the interatrial septum.