Lipomatous hypertrophy of the interatrial septum in a patient with carcinoma: a case report of the importance of multi-modality imaging.

P>Introduction: Lipomatous hypertrophy of the interatrial cardiac septum is a benign disorder. In rare cases, the disorder can cause obstruction of atrial inflow, causing symptoms of heart failure, or cardiac arrhythmias resulting from the involvement of the atrial wall and atrioventricular conduction pathways. Case presentation: We present a case of a Caucasian 66-year-old man with urothelial carcinoma where transthoracic echocardiolography showed a mass in the basal part of the interatrial septum. After injection of echo contrast, it was suggested that the structure was vascularized, thus implying tumour. Transoesophageal echocardiography and cardiac magnetic resonance imaging gave the correct diagnosis of lipomatous hypertrophy. It was then discovered that the patient had been referred to a computed tomography (CT) earlier, but no mention of the mass was found in the report from the examination. Re-evaluation of the images showed a clearly visible mass indicative of fatty tissue. Conclusion: This case report highlights the importance of multi-modality imaging when the findings are not concordant. Moreover, this case report also highlights the importance of careful examination of the heart on routine CT scans, something that is often overlooked by the radiologists. In this case, the CT scan clearly indicated the diagnosis of lipomatous hypertrophy of the interatrial septum and thus could have prevented the subsequent imaging cascade.