Epicardial Lipomatous Hypertrophy Mimicking Pericardial Effusion

Abstract

HomeCirculation: Cardiovascular ImagingVol. 4, No. 1Epicardial Lipomatous Hypertrophy Mimicking Pericardial Effusion Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissionsDownload Articles + Supplements ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toSupplementary MaterialsFree AccessResearch ArticlePDF/EPUBEpicardial Lipomatous Hypertrophy Mimicking Pericardial EffusionCharacterization With Cardiovascular Magnetic Resonance Christopher A. Miller, MRCP and Matthias Schmitt, MD, PhD Christopher A. MillerChristopher A. Miller From the Cardiovascular Magnetic Resonance Unit, North West Regional Cardiac Centre, University Hospital of South Manchester, Manchester, United Kingdom. Search for more papers by this author and Matthias SchmittMatthias Schmitt From the Cardiovascular Magnetic Resonance Unit, North West Regional Cardiac Centre, University Hospital of South Manchester, Manchester, United Kingdom. Search for more papers by this author Originally published1 Jan 2011https://doi.org/10.1161/CIRCIMAGING.110.957498Circulation: Cardiovascular Imaging. 2011;4:77–78IntroductionA 62-year-old man with no history of cardiac disease was referred because of exertional dyspnea. His body mass index was elevated at 29 kg/m2, and a large cutaneous lipoma was present on his abdominal wall. Transthoracic echocardiography was performed and initially reported to demonstrate a moderate-sized global pericardial effusion (Figure 1 and Movies 1 and 2). Consideration was given to pericardiocentesis; however, subsequent review suggested that the appearances may have been due to pericardial thickening (Movie 3). Cardiovascular magnetic resonance (CMR) imaging was performed for clarification.Download figureDownload PowerPointFigure 1. Echocardiographic images. Parasternal long-axis (A) and short-axis (B) views showing the echolucent zone surrounding the heart that was mistaken for a pericardial effusion (asterisk, dashed line). LV indicates left ventricle; RV, right ventricle; LA, left atrium; and Ao, aorta.A thick layer of epicardial tissue, measuring up to 29 mm deep, was seen to surround the myocardium on balanced steady-state free precession (SSFP) cine images (Figure 2 and Movie 4). On both SSFP and half-Fourier single-shot fast spin-echo images, signal intensity was high, indeed identical to that from subcutaneous fat. Using a spatial modulation of magnetization sequence (“tagging”), the epicardial tissue appeared to be adherent to the myocardium (Movie 5). The interatrial septum was also markedly thickened (23 mm), with sparing of the fossa ovalis, and had the same high signal intensity (Figure 2C). Fast spin-echo images with a fat-saturation inversion recovery prepulse (which significantly reduces, or “nulls,” the signal from fat) confirmed the epicardial and interatrial septal tissue to be fat (Figure 3). A diagnosis of epicardial lipomatous hypertrophy with concomitant lipomatous hypertrophy of the interatrial septum was made. The pericardium itself was thin and of normal appearance, with no evidence of pericardial effusion; indeed, the contrast provided by the fat allowed for unusually good delineation of the pericardium, highlighting its cranial extension.Download figureDownload PowerPointFigure 2. Cardiovascular magnetic resonance SSFP images. Left ventricular outflow tract (A), short-axis (B), 4-chamber (C), and coronal (D) images showing extensive epicardial lipomatous hypertrophy (asterisk) and lipomatous hypertrophy of the interatrial septum (double dagger). The pericardium (arrows) has a normal appearance, and its cranial extension is particularly evident (D) due to the contrast provided by the fat. RA indicates right atrium; PA, pulmonary artery.Download figureDownload PowerPointFigure 3. Cardiovascular magnetic resonance fat saturation images. In the corresponding fat-saturation fast spin-echo 4-chamber (A, corresponding to Figure 2C) and coronal (B, corresponding to Figure 2D) views, the signal from the epicardial (asterisk) and atrial septal (double dagger) lipomatous hypertrophy is “nulled,” confirming its fatty composition.Cardiac lipomatosis is characterized by the accumulation of nonencapsulated mature adipose tissue caused by hyperplasia of lipocytes. The etiology is unknown, but it may be associated with obesity and advancing age.1 The most frequent manifestation is lipomatous hypertrophy of the interatrial septum. Massive epicardial lipomatous hypertrophy is less well documented. Although histologically benign, it has been reported to cause cardiac tamponade, requiring decompressive pericardiectomy.2 In the presented case, cine imaging demonstrated normal right heart and caval appearances, phase contrast imaging with velocity encoding demonstrated normal systemic venous inflow, and on real-time, free-breathing imaging, ventricular septal motion was seen to be normal, all of which suggested reassuring cardiac filling physiology.The case highlights the possibility of mistaking epicardial lipomatous hypertrophy for pericardial effusion on transthoracic echocardiography. The tissue characterization provided by CMR allowed the diagnosis to be made, avoiding the need for invasive investigation or unnecessary intervention. The functional data provided by CMR suggested that the epicardial lipomatous hypertrophy was not affecting cardiac function.DisclosuresNone.FootnotesThe online-only Data Supplement is available at http://circimaging.ahajournals.org/cgi/content/full/CIRCIMAGING.110.957498/DC1.Correspondence to Dr Christopher Miller, Cardiovascular Magnetic Resonance Unit, North West Regional Cardiac Centre, University Hospital of South Manchester, Southmoor Road, Wythenshawe, Manchester, UK. E-mail [email protected]org.uk