Multimodality Imaging of a Silent Cardiac Hemangioma.

A 74-year-old man underwent echocardiographic exam for hypertension screening. A fixed plurilobulated mass originating from the right ventricular lateral wall and occupying half of the cavity was incidentally diagnosed. On cardiac magnetic resonance (CMR) it appeared homogeneous, intermediate-to-high signal on T1-weighted, and diffusely hyperintense on T2-weighted images. First pass enhancement was late and heterogeneous and no late gadolinium enhancement was present. Computed tomography (CT) showed no extracardiac infiltration, the feeding artery was a branch of therightcoronary artery. The tumor was excised and histological examination demonstrated a hemangioma of the cavernous type. The postoperative course was uneventful. From 1998 to 2014, four cardiac hemangiomas have been diagnosed in our Department, accounting for 8.7% of all primary cardiac tumors and for 9.5% of all benign forms; estimated population prevalence was 0.11/100.000 inhabitants/year. The hemodynamic consequences of unoperated cardiac hemangiomas cannot be predicted and therefore, resection is recommended.

INTRODUCTION

Primary cardiac tumors are rare,[1] and hemangiomas are believed to represent 1-10% of benign forms. Single casereports are described in literature depicting a heterogeneous pathology with significant clinical differences. Due to the rarity and the possibility of a silent clinical course, decision-making may be difficult. We hereby report a case of right ventricular silent hemangioma and review our previous experience and literature. From 1998 to 2014four cardiachemangiomas, 9.5% of benign primary cardiac tumors, have been diagnosed in our Department. Incidence in the general population, not previously reported, has been estimated. Imaging characteristics of hemangiomas on transthoracic and transesophageal echocardiography, cardiac magnetic resonance (CMR), computed tomography (CT), and angiographyare reviewed.

CASE REPORT

A 74-year-old man underwent echocardiographic exam for hypertension screening. He suffered from hypercholesterolemia and mild chronic obstructive pulmonary disease. The patient was asymptomatic and carried a normal active life.

A fixed plurilobulated mass originating from the right ventricular lateral wall was incidentally diagnosed [Video 1]. Echogenicity was the same as the myocardium, dimensions 35 × 28 cm [Figure 1 Panel a], and neither outflow tract obstruction nor interference with tricuspid valve dynamic was present. On CMR; the mass appeared homogeneous, with intermediate-to-high signal on T1-weighted [Figure 1 Panel b] and diffuse hyperintensity on T2-weighted images [Figure 1 Panel c]. No late gadolinium enhancement was present [Figure 1 Panel d]; first pass enhancement was late and heterogeneous [Video 2 and Figure 2 Panel a]. CT showed no extracardiac infiltration, the feeding artery was a branch of therightcoronary artery [Figure 2 Panel b].

Figure 1

(Panel a) Transthoracic echocardiographic four-chamber view showing the ovalar isoechoic mass originating from the right ventricular lateral wall and occupying half of the RV cavity. (Panel b) Cardiac magnetic resonance T1-weighted sequence with fat suppression short axis view shows homogeneous, intermediate-to-high signal intensity. (Panel c) Cardiac magnetic resonance T2-weighted sequence four-chamber view shows a diffused hyperintensity. (Panel d) Cardiac magnetic resonance T1-weighted sequence short axis view shows absence of late gadolinium enhancement

Figure 2

(Panel a) Cardiac magnetic resonance first pass perfusion imaging showing late and heterogeneous enhancement. (Panel b) Computed tomography modified four-chamber view shows no evidence of pericardial or extracardiac infiltration. (Panel c) On gross examination, the mass appeared russet-colored, homogeneous, and noncapsulated. (Panel d) Histologic specimen, hematoxylin and eosin, original magnification, ×40: Multiple large, thin-walled, dilated vascular spaces (arrow) can be seen within the ventricular wall

Differential diagnosis was between thrombosis and tumor. A thrombus was unlikely as no signs of right ventricular failure, deep venous thrombosis, or pulmonary embolism were present; moreover, infiltration of the RV lateral wall was suspected. MRI signal intensity was not typical of thrombosis and imaging characteristics could suggest a myxoma, which seemed the most probable diagnosis before surgical removal. Malignancy could not be excluded with absolute certainty without histologic confirmation. An endomyocardial biopsy was taken into consideration, but would involve a high embolic and bleeding risk. Although asymptomatic, surgical removal was decided in order to avoid embolic risk, hemodynamic consequences, and pericardial infiltration. On gross examination; it appeared a solitary russet, homogeneous, noncapsulated mass with dimensions 2.5 × 2 × 1 cm; and it was sessile, mildly polilobated, homogeneous soft in consistence [Figure 2 Panel c]. Parietal pericardium was normal. The tumor was completely excised with transventricular approach taking care not to damage the right coronary artery branches. Right ventricular wall was reconstructed with autologous pericardial patch. The postoperative course was uneventful and the patient discharged in good condition on postoperative day 4.

Histological examination demonstrated multiple endothelial-lined, large, thin-walled, and dilated vascular channels with interspersed fibrous septa and filled with blood or thrombosis: Diagnosis of a cardiac heamngioma of the cavernous type was established. No cellular atypia was present [Figure 2 Panel d].

DISCUSSION

From 1998 to 2014, 46 consecutive primary cardiac tumors have been diagnosed in our Department. Benign forms were 42 (91%). Four hemangiomas have been found, accounting for 8.7% of all primary cardiac tumors and 9.5% of benign forms. Hemangiomas estimated population prevalence was 0.11/100,000 inhabitants/year. Mean age was 79 years, male female ratio 3:1. Localization was mitral valve in two cases (one cavernous and one capillary), interatrial septum (arteriovenous type) in one, and right ventricle (cavernous type) in the present case (one). They were all asymptomatic, incidentally found on routine echocardiographic examination and have been operated on without complications.

Cardiac hemangiomas are classified in cavernous, capillary, and arteriovenous. Cavernous types, characterized by multiple dilated thin-walled vessels, are the most frequent. All ages may be affected and a female predominance is described. They can involve atria, ventricles, pericardium, and valves; but no chamber predilection seems to be present. In a review of 56 cases of cardiac hemangiomas, the site of origin was: 36% in the right ventricle, 34% in the left ventricle, 23% in the right atrium,[2] and the rest on the interatrial septum and in the left atrium.[3] These tumors are slow growing, although a rapid growth has been reported in one case.[4]

Echocardiography is the first-line diagnostic tool. Contrast echocardiography can demonstrate a high and rapid contrast uptake. Transesophageal echocardiography may help in estimation of intra- and extracardiac extension, attachment, presence of intracavitary obstruction, or interference with valvular dynamics. CT and CMR provide more useful information about the invasiveness of the tumor and extracardiac extent. Hemangiomas appear heterogeneous at unenhanced chest CT, and intensely enhanced after contrast injection.[5] Foci of calcification may be present. CMR demonstrates intermediate signal intensity on T1-weighted and hyperintense on T2-weighted images due to high water content; on first pass perfusion imaging a rapid and strong fill-in is characteristic, mass “disappearance” in the intracavitary blood pool suggests highly vascular nature. Late gadolinium enhancement is typically absent, although focal areas of fibrosis may be present. Cardiac catheterization demonstrates the blood supply and a tumor blush due to the high vascularity, although sometimes dilated vascular channels cause slow flow and absence of first pass perfusion enhancement.[56] A definitive diagnosis requires histologic examination.

CONCLUSIONS

Cardiac hemangiomas are often asymptomatic, but may present with arrhythmias, complete heart block,[6] sudden death,[7] dyspnea, congestive heart failure, outflow tract obstruction, coronary insufficiency, pericardial effusion, and tamponade.[89] The hemodynamic consequences of unoperated cardiac hemangiomas cannot be predicted; therefore, although spontaneous resolution has been reported,[10] resection is always recommended.[11] Patients with resectable tumors usually have a favorable long-term prognosis.