Contrasting fatty involvement of the right ventricle: lipoma versus lipomatous hypertrophy.

We report two rare cases of right ventricular lipomatous involvement, and discuss their contrasting diagnostic images and clinical manifestations. Case 1 is a 21-year-old Malay man who presented with recurrent syncope. Transthoracic echocardiography showed a homogeneous discrete mass attached to the right ventricular septum, occupying the right ventricular outflow tract. Cardiac magnetic resonance (MR) imaging showed features consistent with intracardiac lipoma, which was confirmed on histology, upon surgical resection. Case 2, a 73-year-old Caucasian woman, was found to have incidental lipomatous infiltration of the right ventricle on echocardiography and MR imaging. In contrast to the well-defined right ventricular lipoma seen in the first case, lipomatous involvement was manifested as a diffuse homogeneous thickening of the right ventricular free wall. Multimodality imaging allows for a complementary and detailed characterisation of lipomatous masses involving the ventricular septum.