Lipomatous Hypertrophy of the Interatrial Septum (LHIS)

Abstract

A 72 year old female patient presented to the emergency with abdominal pain. Contrast enhanced CT scan of the abdomen and the pelvis was ordered [1]. The CT of the abdomen and pelvis was unremarkable, however in the included portion of the chest a mass lesion was present involving the region of the atrial septum. The lesion had characteristic dumbbell shape sparing the fossa ovalis (Figure 1) and measured 92 Hounsfield units (Figure 2) which denotes presence of macroscopic fat ( 60 to 120 HU). A diagnosis of Lipomatous hypertrophy of the interatrial septum (LHIS) was made. The ordering physician and the patient were assured to the benign nature of this process [2-4].