Lipomatous hypertrophy of the interatrial septum: A case report and insights from the literature

Abstract

Lipomatous hypertrophy of the interatrial septum (LHIS) is a histologically benign cardiac lesion that is defined by excessive fat accumulation in the area of the interatrial septum (IAS) that does not include the fossa ovalis. Another unusual illness is lipomatosis, which is defined as a broad overgrowth of mature adipose tissue that involves a large portion of an extremity or trunk. We describe a rare case with significant LHIS accompanied by subcutaneous lipomatosis. Echocardiography revealed a mass in the right atrium in this patient. Magnetic resonance imaging revealed that this mass was composed of the adipose tissue and was an extension of a huge thickened IAS. Furthermore, this significant hypertrophy of the IAS was in direct continuation with the excessive mediastinal and epicardial fat.

Importance of Multimodality Cardiac Imaging in the Diagnosis of Lipomatous Hypertrophy of the Interatrial Septum—A View beyond Standard Situations

“…Cardiac magnetic resonance describes the same aspect of a clearly defined mass, with a characteristically high-intensity signal in T1-weighted images with mild inhomogeneous late gadolinium enhancement, highlighting fat accumulation [22]. A clear differentiation between adipose and muscular tissue can be made, as both blood and adipose tissues have a high T1/T2 ratio, providing a strong signal, whereas the myocardium has a low ratio, thus providing a low signal [5]. The same aspect was described in our case.…”

“…Several authors reported the same suboptimal defined aspect, requiring a better visualization of the IAS. Licordari R. et al demonstrated a right atrial mass with no clear definition in a 55-year-old patient also suffering from hypertension, obesity, and subcutaneous lipomatosis [5]. Lampropoulous K.M.…”

“…The same aspect was described in our case. Licordari R. et al performed CMR for their case, describing the aforementioned aspects as well as the so-called "India-ink artefact" that appears as a low signal, delineating LHIS at the fat-water interface [5].…”

“…The role of brown adipose tissue at this level is still unknown. Going by the definition, hypertrophy is present beyond the value of 20 mm, sometimes reaching 30 mm while respecting the FO [5][6][7][8][9]. Usually, it is related to advanced age, obesity, and female gender, and it is a benign entity [2,10].…”