Neonatal Cardiac Rhabdomyoma: A Silent Dissolution

A 2-month-old infant was urgently referred to our hospital due to a suspected cardiac tumor. The infant was born at 36 weeks of gestation with a birth weight of 2500 g and Apgar scores of 8 and 9 at 1 and 5 min, respectively. Prenatal ultrasound examination at 36 weeks of gestation first revealed a suspicious mass within the fetal heart. Postnatally, the infant maintained stable vital signs, with normal cardiovascular examination results, and there was no family history of tuberous sclerosis complex. Transthoracic echocardiography (TTE) revealed a 22 × 13 mm lesion adherent to the right ventricular free wall. The lesion exhibited heterogeneous echotexture, and had a regular shape with well-defined borders. The right ventricular outflow tract (RVOT) appears morphologically narrow, but there are no significant hemodynamic abnormalities. The pulmonary valve is normal, and the pulmonary arteries are patent (Figure 1 A1, A2). Subsequent cardiac CT angiography (CTA) confirmed the lesion's characteristics within the right ventricle (Figure 1 B1, B2), affirming its attachment to the free wall without enhancement, while simultaneously ruling out pulmonary artery embolism. An integrated analysis of imaging findings and clinical data yielded a diagnosis of cardiac rhabdomyoma. Considering the non-invasive nature of the tumor and the infant's stable clinical condition, a surveillance plan consisting of semiannual to annual TTE assessments was established to closely monitor the rhabdomyoma's evolution. Gratifyingly, over the course of three consecutive follow-ups (Figure 2 A-C/1-2), the rhabdomyoma displayed a progressive diminution, culminating in complete disappearance. Cardiac rhabdomyomas represent the most common primary cardiac tumors in pediatrics, often undergoing spontaneous involution [1, 2]. However, when life-threatening cardiovascular obstructions or refractory arrhythmias unresponsive to pharmacotherapy arise [3], pharmacological or surgical intervention becomes necessary [4]. This case vividly illustrates the complete journey from initial diagnosis to spontaneous regression of a cardiac rhabdomyoma. It underscores the effectiveness of conservative management through meticulous ultrasound surveillance in cases of asymptomatic obstructive lesions or drug-resistant arrhythmias. The diligent follow-up in this instance not only captures the natural progression and resolution of the tumor but also highlights the critical importance of such monitoring for optimal patient care and outcomes. Hospital exempted from ethics review in view of retrospective cases. This report has obtained the patient's informed consent for the publication of their anonymized clinical data. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author.