Lipomatous hypertrophy of the interatrial septum is a pathologic, not an anatomic diagnosis.
Kevin R AnJagdish ButanyRobert J CusimanoPublished in: Journal of cardiac surgery (2020)
On rare occasions, LHIS can arise from outside the interatrial septum. An LHIS can be differentiated from a lipoma by the presence of entrapped cardiac myocytes in LHIS, making it a pathological, rather than an anatomic, diagnosis.