1344094 - Right Ventricular Cavernous Hemangioma in a 12-year-old Patient

A 12-year-old boy was referred to our pediatric cardiology clinic for evaluation of palpitations that he reported for five months prior. These episodes were not associated with syncope, dizziness, dyspnea, or chest pain. He was active, played football and baseball, and was otherwise healthy. His clinical examination was normal.

Diagnostic Techniques and Their Most Important Findings:

At the clinic, the patient had a 12-lead electrocardiogram that showed sinus bradycardia (heart rate 50 bpm) without preexcitation. A 14-day extended Holter monitor showed several narrow and wide complex tachycardia episodes at 180-195 bpm, likely supraventricular tachycardia (SVT) with aberrancy. The patient had a transthoracic echocardiogram that showed a large mass measuring 2.1 x 2.9 x 3.4 cm attached to the anterolateral wall of the right ventricle (RV) (Figure 1). The mass did not appear to cause any RV inflow or outflow obstruction.

He underwent a cardiovascular MRI (CMR) study (Figure 2) on a 1.5 T scanner (Siemens Healthineers, Erlangen, Germany) for tissue characterization of the mass. CMR confirmed the presence and the position of the mass by steady-state free-recession (SSFP) cine sequence. The mass was hyperintense in the SSFP sequence and T2 weighted imaging; isointense by first-pass perfusion imaging and hyperintense by late gadolinium enhancement imaging (LGE). T1 (ShMOLLI) and T2 mapping demonstrated prolonged times at 1567 and 72 msec, respectively. These findings suggested that the mass was of vascular origin. Differential diagnosis included hemangioma and other vascular tumors. After a multidisciplinary discussion, he underwent an electrophysiological study which showed inducible atrioventricular nodal reentrant tachycardia (AVNRT) not in close proximity to the mass. He had successful cryoablation of the slow pathway region. Subsequently, he underwent surgical resection of the RV mass (measured 4 x 3.6 x1.5 cm). Histopathological examination showed a poorly circumscribed lesion containing predominantly thin-walled capillary structures insinuating between the native cardiac myocytes and collections of pericytes without atypia or necrosis (Figure 3). Immunoperoxidase stains were performed with appropriate controls. CD31 and CD34 highlighted the tumor endothelial cells and smooth muscle actin highlighted the pericytes. The morphologic and immunohistochemical features were indicative of an intramural cavernous hemangioma. His postoperative course was uneventful.

Learning Points from this Case:

Primary cardiac tumors are rare, and around 75% of them are benign. Among these primary tumors, hemangiomas represent 2.8%.¹ The clinical presentation varies based on the size and location of the mass. Although cardiac hemangiomas were reported previously,^2,3 we highlight that due to the contemporary advancement in cardiac imaging modalities, a thorough CMR examination can lead to precise tissue characterization for cardiac masses with a high pretest probability.^4,5