A Surgical Case of Lipomatous Hypertrophy of the Atrial Septum

Abstract

We present a rare case of lipomatous hypertrophy of the atrial septum (LHAS) characterized by the abnormal accumulation of adipose tissue within the interatrial septum, forming a tumor-like mass. The reported incidence of LHAS is 2.2–8%, with advancements in imaging techniques expanding diagnostic opportunities. A 75-year-old female with a history of meningioma, right breast cancer, cholecystolithiasis, and ovarian cyst; comorbidities, including diabetes, hypertension, and hyperlipidemia; and a body mass index of 33 kg/m² underwent resection for an enlarging interatrial septal tumor, ultimately leading to the diagnosis of LHAS. Imaging revealed a 36 mm × 28 mm tumor extending from the atrial septum into the right atrium, with a computed tomography value of –76 HU. Histopathologically, the tumor was mainly composed of mature adipocytes along with hypertrophied myocardial fibers and scattered brown adipocytes, confirming the diagnosis of LHAS. Although LHAS is often managed with observation following diagnosis, our report on surgical intervention presents a rare and noteworthy occurrence. This case highlights the importance of recognizing and addressing the rare occurrence of LHAS, which often requires surgical intervention in cases of tumor enlargement. The successful resection and diagnosis of LHAS in this patient underscore the importance of considering this condition in the differential diagnosis of cardiac tumors.