Right atrial and SVC infiltrating mass-the entity of infiltrating lipoma

Cardiac lipomas are rare benign primary cardiac tumours primarily composed of mature adipocytes. They are usually well defined, encapsulated masses, but rarely demonstrate malignant characteristics by infiltrating the myocardium. This causes diagnostic uncertainty as it becomes a priority to rule out primary malignant cardiac tumours such as sarcoma which often carry a poor prognosis.

A 61 year old female presenting with chest pain was found to have an infiltrating right atrial hypertrophic mass. Mutli-disciplinary team (MDT) discussions along with the presence of symptoms and likelihood of malignancy led to the recommendations for surgery. Intraoperatively this involved the right pulmonary veins and superior vena cava (SVC). The mass was resected with good margins and reconstruction of the right atrium, pulmonary veins and SVC was done using porcine pericardial patch. The patient made a good postoperative recovery and was discharged home in sinus rhythm with no significant valvular lesions. This was further confirmed at 6 month follow up. Final histology was that of infiltrating lipoma.

In this rare case of infiltrating cardiac lipoma in a relatively young patient, the diagnostic uncertainty despite multimodal imaging meant surgery was indicated due to the high suspicion of cancer. Even in benign cases, fatty infiltration can lead to conduction defects and embolisation. Technical difficulties in sectioning these specimens is caused by intra-tumour variability and current recommendations are for excision biopsy, for best characterisation. The management of these patients requires an MDT with Cardiac surgery being a safe approach providing definitive management.