Invasive Lipoma of the Interventricular Septum, a Rare Benign Cardiac Mass With Atypical Presentation and Management

Lipoma of the interventricular septum involving the tricuspid valve is a rare entity. A 50-year-old woman presented with exertional dyspnea. She was found to have a large right interventricular septal mass in the initial transthoracic echocardiography. This mass was further investigated by transesophageal echocardiography, cardiac gated CT, and cardiac magnetic resonance imaging. It was found to be lipomatous and embedded into the septal leaflet of the tricuspid valve. The diagnosis was confirmed by biopsy. Surgical exploration revealed that the mass was deeply embedded in the interventricular septum and septal leaflet of the tricuspid valve. The mass was resected along with sections of the interventricular septum and tricuspid valve. She underwent bioprosthetic tricuspid valve placement and patch reconstruction of the interventricular septum. We also searched case reports from MEDLINE and studied pathological and epidemiological characteristics of the published cases of cardiac masses in the past year. Cardiac lipoma although a benign tumor can cause serious hemodynamic complications. Initial transthoracic echocardiography followed by multimodality imaging is the cornerstone of the diagnosis.