A Case of Cardiac Infiltrating Lipoma in the Interatrial Septum

(Division of Cardiovascular Surgery, Kimitsu Chuo Hospital, Kisarazu, Japan)

Hirofumi Nishida Yoshio Sudou Hideo Ukita
Nobuyuki Nakajima
A 75-year-old woman presented with chest pain on exertion. Cardiac catheterization revealed double vessel coronary artery disease. Echocardiographic examination showed the presence of an abnormal mass in the interatrial septum without any flow velocity signal within the mass. She was scheduled for elective coronary artery bypass grafting. The lesion appeared as a homogeneous mass on CT scan, with an attenuation coefficient of |122 Hounsfield units, suggestive of lipoma. A T1-weighted MRI scan demonstrated that the signal intensity of the interatrial mass corresponded to that of fatty tissue. On surgery with cardiopulmonary bypass a large mass was found to involve the right atrial wall, the interatrial sulcus and the interatrial septum. The mass could not be resected completely, because it adhered strongly to the septal myocardium. On histological examination, the tumor was composed of mature fatty tissues, was not encapsulated and was diagnosed as infiltrating lipoma. The postoperative course was uneventful. CT, MR imaging and color Doppler ultrasonography were very useful in making a tissue-specific diagnosis.
@Jpn. J. Cardiovasc. Surg. 33: 329-332 (2004)