Huge Pericardial Hemangioma Imaging
A 37-year-old healthy woman presented to our emergency department because of episodes of palpitation and syncope. Her general physical examination was unremarkable. The x-ray of her chest was normal except for bulging near the left border of her heart (Figure 1). Her ECG exhibited sinus tachycardia and short runs of monomorphic ventricular tachycardia. Consequently, the patient was admitted to the cardiology intensive care unit for further investigation. Transthoracic echocardiogram and transesophageal echocardiogram showed a large, rounded, extracardiac hypoechogenic mass within the posterosuperior portion of the heart (Figure 2A). Further evaluation of the mass was performed by cardiac computed tomography angiography using 64-row multidetector computed tomography. Cardiac computed tomography angiography revealed a large, hypodense, epicardial solid mass (9×6×6 cm) with small central areas of enhancement. The mass was located posteriorly to the right ventricle outflow tract and ascending aorta, at the level of the left coronary sinus of Valsalva, causing compression and displacement of the left atrium and the left superior pulmonary vein. In addition, the left main coronary artery, the left anterior descending artery, the left circumflex artery, and the first diagonal artery were completely surrounded by the tumor and showed diffuse, slight narrowing (Figure 2B and 2C). On operating, the mass was unresectable because of its proximity to the coronary arteries. A histological examination revealed a cavernous-type hemangioma (Figure 2E). One week after the operation, cardiac magnetic resonance imaging was performed and showed a large, well-defined epicardial mass. In addition, magnetic resonance imaging confirmed that the myocardium was not involved and revealed moderate pericardial effusion (Figure 2D and Movies I through III). On first-pass perfusion dynamic magnetic resonance imaging, after administration of gadolinium contrast media, the mass showed some areas of intense enhancement (Movie IV). Fifteen minutes after gadolinium administration, there was intense delayed homogeneous enhancement within the mass, indicating delayed slow blood flow (Movie V).
No feeding vessel was found when a coronary angiography was subsequently performed. Taking into consideration the repeated episodes of ventricular tachycardia, an intracardiac defibrillator was implanted, and the patient is now a candidate for cardiac transplantation.
The incidence of primary cardiac tumors is estimated to be between 0.001% and 0.03% at autopsy.1 Among primary tumors of the heart, hemangiomas account for 5% to 10% of the benign tumors.1 Cardiac hemangiomas are composed of endothelial cells that line interconnecting vascular channels; histologically, they can be capillary, cavernous, or arteriovenous in nature. Hemangiomas may involve the endocardium, myocardium, or epicardium. They are usually asymptomatic, and the symptoms depend on the anatomic location of the tumor; they have been reported to induce arrhythmias and pericardial effusions, effort dyspnea, congestive heart failure, pseudoangina, outflow tract obstruction, and coronary insufficiency.2 The resectability depends on the tumor’s location and whether the myocardium, coronary arteries, or great vessels are involved. Both cardiac computed tomography angiography and magnetic resonance imaging may play an important role in the evaluation of cardiac hemangioma, providing valuable information regarding size, location, morphology, and the relationship to adjacent mediastinal structures. The computed tomography appearance of hemangioma consists of a well-defined, soft–tissue density mass, with or without calcifications, that usually shows patchy areas of enhancement after administration of iodinated contrast media. At magnetic resonance imaging, hemangiomas are heterogeneously isointense or hypointense on T1-weighted images and are usually hyperintense on T2-weighted images. They typically show inhomogeneous intense enhancement after administration of gadolinium. Characteristically, the enhancement occurs in the late phase of contrast administration because of delayed venous filling. Knowledge of these imaging features of hemangiomas is important for accurate diagnosis and management.
The online-only Data Supplement, consisting of Movies I through V, is available with this article at http://circ.ahajournals.org/cgi/content/full/115/10/e315 /DC1.