A Rare Presentation of Fetal Cardiac Rhabdomyoma: Prenatal Diagnosis and Perinatal Management

Fetal cardiac rhabdomyoma is an uncommon benign cardiac tumour and is the most frequently encountered primary cardiac tumour during fetal life. Its prenatal recognition is clinically important because cardiac rhabdomyomas are strongly associated with tuberous sclerosis complex (TSC), particularly when lesions are multiple. We report a 28-year-old primigravida referred at 27 weeks after an echogenic cardiac mass was identified at the routine anomaly scan at 20 weeks. Targeted ultrasonography and fetal echocardiography at 28 weeks demonstrated multiple homogeneous echogenic masses involving both ventricles and the interventricular septum, the largest measuring approximately 2 cm, with mild restriction of left-sided atrioventricular flow. No extracardiac abnormalities or hydrops were identified. The pregnancy was followed with fortnightly surveillance for hydrops, cardiac dysfunction and arrhythmia, with multidisciplinary counselling involving maternal-fetal medicine, neonatology, paediatric cardiology and genetics. Elective caesarean delivery at 38 weeks resulted in a 3-kg male neonate with normal cardiac function and rhythm at birth. Postnatal echocardiography confirmed significant biventricular rhabdomyomas without outflow obstruction. This case highlights the importance of detailed fetal echocardiography, surveillance for haemodynamic compromise, and evaluation for TSC after prenatal detection of cardiac rhabdomyoma. Recent literature supports an expectant approach in haemodynamically stable fetuses, while selected severe cases with progressive obstruction or cardiac compromise may be considered for mTOR-inhibitor therapy in specialist centres.