Neonatal right ventricular rhabdomyoma: Imaging findings and spontaneous regression.

Neonatal cardiac rhabdomyoma is a rare benign mesenchymal tumor that frequently serves as the sentinel clinical marker for tuberous sclerosis complex (TSC). We report a case of a term female neonate presenting with immediate respiratory distress and a Silverman score of 4/10. Initial transthoracic echocardiography (TTE) on day 3 of life revealed a voluminous, multilobulated, hyperechoic mass measuring 28 mm × 16 mm occupying the right ventricular cavity, involving both the inflow and outflow tracts. Despite the significant tumor burden, hemodynamic stability was maintained without significant outflow tract obstruction or arrhythmias, allowing for a successful conservative management approach. A comprehensive systemic screening protocol-including brain magnetic resonance imaging (MRI) and renal ultrasonography-was negative for additional stigmata of TSC. Follow-up at 2 years demonstrated complete clinical stability and significant spontaneous tumor regression to 11 mm × 6 mm. This case highlights the necessity of multimodal imaging for diagnosis and risk stratification, while reinforcing the favorable natural progression of nonobstructive rhabdomyomas.