Huge cardiac rhabdomyoma in a neonate: A surgical challenge

Abstract

Cardiac rhabdomyomas are the most common primary cardiac tumors observed in neonates and children, which have been frequently associated with the tuberous sclerosis complex. These benign tumors usually have a natural history of regression but can sometimes cause significant clinical issues by obstructing blood flow and arrhythmias. We present an unusual case of a neonate who presented with a large cardiac rhabdomyoma with obstruction to the right ventricular inflow and outflow. The tumor necessitated an urgent surgery, which proved to be technically challenging.

INTRODUCTION

Cardiac tumors in neonates are rare, with an estimated incidence of 0.02%–0.08% of all live births.[1] Among these, rhabdomyomas are the most prevalent, accounting for approximately 60%–90% of all primary cardiac tumors in children.[1] These benign tumors are frequently associated with tuberous sclerosis complex (TSC), which is due to mutations in the TSC1 or TSC2 genes.[2,3] Approximately 70%–90% of patients with cardiac rhabdomyomas have underlying TSC, making the identification of these tumors a critical component in the early diagnosis and management of TSC.[4,5]

The diagnosis is primarily made by echocardiography, although additional imaging modalities, such as cardiac computed tomography (CT) and magnetic resonance imaging (MRI), may be required to provide further information in some cases.[6] Management of cardiac rhabdomyomas is typically conservative. The prognosis for infants is generally favorable, particularly when the tumors are not associated with severe cardiac dysfunction or arrhythmias.[7,8]

Herein, we describe a case of a newborn diagnosed with a cardiac rhabdomyoma at birth. She went on to develop symptoms of heart failure during her neonatal period, for which she underwent an urgent surgical intervention.

CASE REPORT

A 20-day-old female child weighing 2.6 kg was brought to our hospital with complaints of tachypnea and poor feeding. She was tachycardic and in respiratory distress with cold extremities and a capillary refill time of >5 s. Upon auscultation, a systolic murmur could be heard all over the precordium. Given these findings, an urgent echocardiogram was performed, which revealed a large and well-defined mass filling the right ventricular cavity, measuring approximately 24 mm × 28 mm in size. The mass was attached to the interventricular septum, resulting in almost the entire right ventricular cavity being filled. Moreover, the mass extended even into the right ventricular outflow tract, causing a significant obstruction to both ventricular inflow and outflow. The patient was admitted to the cardiac intensive care unit and started on respiratory support, intravenous fluids, ionotropic support (dobutamine), and prophylactic antibiotics. Baseline investigations ruled out sepsis, whereas the electrocardiogram showed normal sinus rhythm. Due to the increasing respiratory distress and signs of imminent heart failure, urgent surgical intervention was planned to excise the rhabdomyoma.

Surgical technique

The chest was opened through a midline sternotomy. Cardiopulmonary bypass was instituted through aortobicaval cannulation. The heart was arrested by antegrade cardioplegia, and the right atrium was opened. The right ventricular tumor was found to be popping through the tricuspid valve and was densely adherent to the right ventricular myocardium all around. The tricuspid valve papillary muscle was seen to be originating from the tumor mass [Figure 1]. Since the tumor mass was huge and stuck all around, it had to be excised in pieces [Figure 2]. An island of papillary muscle base was taken out with subsequent translocation and transfixation medially at the interventricular septum. In view of expected right ventricular dysfunction, a small atrial septal defect was left open.

Figure 1.

Preoperative echocardiogram. RA: Right atrium, LA: Left atrium, RV: Right ventricle, LV: Left ventricle

Figure 2.

Intraoperative excision of tumor mass in pieces. RA: Right atrium, RV: Right ventricle

The right atrium was closed, and the aortic cross-clamp was released after deairing. The heart reverted to a sinus rhythm with occasional ventricular ectopic beats. Cardiopulmonary bypass was slowly weaned off with inotropic support to the heart.

The patient’s chest was kept open for the next 2 days after surgery in view of frequent ventricular ectopics and blood pressure instability. The chest was closed after hemodynamic stability was achieved and amiodarone was initiated, which reduced the frequency of premature ventricular beats. A postoperative echocardiogram confirmed the complete excision of the rhabdomyoma along with mild right ventricular dysfunction, mild tricuspid regurgitation, and a small decompressive atrial septal defect shunting from the left to the right [Figure 3]. Inotropes and respiratory support were gradually tapered over 8–10 days, and the patient was discharged after two weeks in good general condition and on full feed.

Figure 3.

Postoperative echocardiogram. RA: Right atrium, RV: Right ventricle, LV: Left ventricle

The biopsy of the lesion, which was collected intraoperatively, revealed a rhabdomyoma. The patient was further referred to the neurology department for an MRI of the brain to assess for tubers and to the genetics department for genetic testing for TSC.

DISCUSSION

Cardiac rhabdomyomas are the most common primary cardiac tumors in pediatric patients, accounting for approximately 60%–90% of all cases.[1] Despite their significant prevalence amongst cardiac tumors in children, they remain rare, with an estimated incidence of 0.02%–0.08% of live births.[1] Rhabdomyomas are often associated with TSC, which is a genetic disorder characterized by the presence of benign tumors in multiple organs.

The clinical presentation of cardiac rhabdomyoma varies depending on the size, number, and location of the tumors. In utero, these tumors may be detected through fetal echocardiography, often prompting further investigation for TSC. Postnatally, symptoms can range from predominantly asymptomatic findings to severe cardiac dysfunction, inflow or outflow obstruction, and arrhythmias.

The primary modality for diagnosing cardiac rhabdomyoma in neonates is echocardiography, which provides detailed information about the size, location, and number of tumors. Cardiac MRI or CT scans offer additional anatomical and tissue characterization. In cases where TSC is suspected, a comprehensive evaluation with a multidisciplinary team, including neuroimaging and genetic testing, is warranted.[8]

The management of cardiac rhabdomyomas is largely conservative as these tumors often regress spontaneously over time.[9] However, surgical or pharmacological intervention is necessary in cases with significant hemodynamic compromise or intractable arrhythmias, as seen in our case. Our patient’s intractable symptoms forced us to carry out a surgical excision of the tumor by a novel surgical technique as mentioned in the case report.

Rhabdomyomas have been shown to decrease in size with the use of mammalian target of rapamycin (mTOR) inhibitors (sirolimus or everolimus), and several case reports in the literature have cited their effectiveness.[10] We did not use an m-TOR inhibitor as our patient required a more urgent form of intervention.

CONCLUSIONS

Our case highlights the importance of prompt recognition and decision-making in the diagnosis of a cardiac mass in neonates. Early detection and thorough evaluation of associated conditions, such as TSC, are also crucial for effective management and follow-up. While conservative management is often sufficient in cases of cardiac rhabdomyoma, timely surgical intervention can be life-saving in cases with significant hemodynamic compromise. The favorable outcome in this case underscores the effectiveness of prompt surgical treatment and the importance of multidisciplinary care in managing complex cases involving cardiac tumors and genetic syndromes.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.