Echocardiographic History of an Asymptomatic Congenital Cardiac Tumor No Changes in Mass Dimensions During a 14-Year Follow-Up

A14-year-old girl with a history of a congenital cardiac tumor presented to our echocardiography laboratory for a routine reexamination. The diagnosis had been made in our laboratory in 1991 on her seventh day of life using an old-generation ultrasound machine (SSH-40A, Toshiba Medical Systems, Tokyo, Japan). The newborn had undergone echocardiographic evaluation because of a systolic murmur. Despite the low technical quality of the images (Figure 1 and Movie I), a large mass involving the interventricular septum (4.2 1.5 cm, as measured from the apical 4-chamber view), suggestive of a congenital cardiac tumor, was visualized. Subsequent analyses had supported the diagnosis of cardiac rhabdomyoma. No other significant comorbidities, including tuberous sclerosis—a genetic condition often associated with the presence of cardiac rhabdomyoma1—had been discovered. Because of the absence of symptoms, a conservative approach was adopted. Clinical and echocardiographic follow-up during the subsequent years showed substantial tumor stability, with no development of symptoms. At the present examination, the girl was asymptomatic and in good condition. Two-dimensional echocardiography (Sonos 7500 Live 3D Echo, Philips Medical Systems, Andover, Mass) showed an inhomogeneous echogenic mass arising from the mid-apical portion of the interventricular septum (Figures 2 to 4). The dimensions of the mass at end-diastole were similar to those measured at birth (4.4 cm, 1.6 cm, and 3.0 cm in the craniocaudal, transverse, and anteroposterior axis, respectively). In accordance with the muscular nature of the tumor, the mass showed a slight thickening throughout systole (Movies II to IV). The rest of the heart was structurally normal, and no functional abnormalities were found. Real-time 3-dimensional imaging and offline quantitative analysis of data (3DQ-QLAB advanced quantification software, version 3.0, Philips Ultrasound) allowed detailed visualization of the mass, revealing an irregular multilobed architecture with inhomogeneous echogenicity and a torsional–dyskinetic movement during systole (Figures 5 and 6 and Movie V). Tumor dimensions were only slightly larger than those measured by the 2-dimensional approach (craniocaudal: 4.6 cm; transverse: 1.8 cm; anteroposterior: 3.1 cm; volume: 13.9 cm). Congenital cardiac tumors are rare occurrences, having a prevalence of 0.14%.2 Rhabdomyomas are the most common tumors, accounting for about 50% of all cases in children.3 A strong association with tuberous sclerosis has been reported. Among subjects with cardiac rhabdomyoma, 51% to 86% have tuberous sclerosis, whereas more than half of patients with tuberous sclerosis show cardiac rhabdomyomas.1 These rhabdomyomas are usually characterized by multiple masses, with a peduncolated or rounding intramural shape, and they most commonly involve the ventricular myocardium. Cardiac rhabdomyomas may present at birth with a wide spectrum of clinical features, ranging from occasional echocardiographic detection in asymptomatic newborns to presentations with cardiac rhythm disturbances, Wolff-Parkinson-White syndrome, congestive heart failure caused by flow obstruction or valve regurgitation, and/or sudden death. Cardiac symptoms represent a common finding in the first years of life, but spontaneous regression of the tumor occurs in the majority of cases.4 These images illustrate the echocardiographic history of an isolated congenital cardiac rhabdomyoma in an asymptomatic female patient. The evolution of ultrasound techniques—particularly the possibility of performing realtime 3-dimensional imaging— has allowed considerably higher definition of tumor characteristics throughout years. The following unusual aspects should also be pointed out: 1) The tumor was not associated with tuberous sclerosis; 2) the rhabdomyoma was characterized by a single, multilobed mass; 3) the patient did not develop any cardiac symptom; and 4) the dimensions of the mass did not change significantly during a 14-year follow-up.