Compression of the Superior Vena Cava by an Interatrial Septal Lipoma: A Case Report

Primary cardiac tumours are rare; their prevalence ranges from 0.0017% to 0.28% in various autopsy series. Cardiac lipomas are well-encapsulated benign tumours typically composed of mature fat cells, and their reported size ranges from 1 to 15？cm. They are usually seen in the left ventricle and the right atrium. Lipomas are true neoplasms, as opposed to lipomatous hypertrophy of the interatrial septum, which is a nonencapsulated hyperplastic accumulation of mature and foetal adipose tissue. Cardiac lipomas occur in patients of all ages, and the frequency of occurrence has been found to be equal in both sexes. Patients are usually asymptomatic, although the manifestation of symptoms depends upon both size and location of the tumour. We present the case of a patient with an interatrial septal lipoma, causing obstruction of the superior vena cava. 1. Case Report A 45-year-old woman was referred by her general practitioner, with a history of dyspnoea and occasional cyanotic spells. She described a three-month history of progressive shortness of breath, tachypnoea, and headaches. Physical examination revealed facial oedema and cyanosis of the head and shoulders. The superficial veins of the upper extremities and neck were dilated. She had a normal pulse rate and a regular rhythm. Her blood pressure was recorded at 115/70. No heart murmur or thrill was present. There was no hepatomegaly or lower-extremity oedema. The electrocardiogram was negative for ischemia and showed sinus rhythm. Laboratory investigations were normal, except for a mildly lowered haemoglobin level. A radiograph of the chest did not reveal pulmonary vascular congestion, pulmonary oedema, or cardiomegaly. Subsequent computed tomography (CT) of the chest disclosed a low-density soft-tissue mass in the upper part of the interatrial septum that was compressing the superior vena cava (SVC). The mass measured ？cm and had a Hounsfield number of ？100, consistent with fat (Figure 1). The lumen of the SVC was significantly narrowed (Figures 2, 3, and 4), as shown on the CT scan by the anterior displacement of contrast material caused by extraluminal compression. There were no other significant positive findings. Figure 1: Axial CT image with intravenous contrast, showing the interatrial septal lipoma (encapsulated). Figure 2: A second axial image, more cephalad, shows the septal lipoma, compressing the superior vena cava. Figure 3: Coronal reconstruction, showing the entire length of the superior vena cava, that is, from the right and left brachiocephalic veins down to the right atrium. Compression