CASE REPORT
A 60-year-old male with background of atrial fibrillation, hypertension and chronic obstructive pulmonary disease was admitted to his local hospital with acutely worsening shortness of breath. Patient consent was obtained for this report. Ethical approval was waived. Data sharing is not applicable to this article as no new data were created or analyzed in this study. Computed tomography (CT) chest showed a mass in the right side of the pericardium. (Figure 1) The patient was discussed by both cardiology and respiratory multidisciplinary teams (MDT); it was decided to urgently transfer to a tertiary cardiac centre for further assessment including positron emission tomography (PET) scan to exclude metastasis from suspected pericardial tumour and consideration of surgery.
Following transfer, the patient experienced significantly worsening shortness of breath and was also unable to undergo PET scan due to significant symptoms of SVC obstruction and tamponade. Therefore, decision was made to proceed to emergency surgery. Under general anaesthetic, via median sternotomy the pericardium was opened. A mass was found in right atrial wall invading intra-atrial groove and extending over SVC. Following institution of cardiopulmonary bypass the tumour was removed en bloc with the right atrial free wall and dissected from the interatrial septum. The atrium was reconstructed with bovine pericardial patch. The patient was weaned easily from bypass and closed in the usual fashion.
Histology showed a fatty tumour weighing 120g, extensive replacement of myocardium with a vascularised lipomatous tumour composed of lobules and less well defined files of mature adipocytes admixed with variable proportions of multivacuolated brown fat cells and areas of bland spindle cells. The conclusion is that the tumour was a hibernoma with no evidence of malignancy.
Post-operatively, the patient was transferred to intensive therapy unit (ITU) and initially made a good recovery. On the fourth post-operative day, he developed type 1 respiratory failure requiring nasal high flow oxygen therapy. Despite four anti-arrhythmic agents, the patient continued to experience intermittent atrial fibrillation with fast heart rate and therefore underwent direct current cardioversion (DCCV), which was successful. He was subsequently stepped down to the ward and discharged home. At four months follow up, the patient was doing well. Repeat echocardiogram and CT showed dilated right atrium, but no occupying mass. LV ejection fraction was 55-60% and RV function were normal.