Innocent until proven guilty? Longstanding atrial ectopy preceding cardiac rhabdomyoma diagnosis in tuberous sclerosis complex: a case report

BACKGROUND: Cardiac rhabdomyoma are the most common cardiac tumour in childhood and are associated with tuberous sclerosis complex (TSC) up to 96% of infant cases. They classically manifest in the foetal and neonatal period, undergo spontaneous regression in the first years of life and are associated with arrhythmia in part due to interruption of normal conduction pathways by the tumour. CASE SUMMARY: We present a case of a 3-year-old boy with a long-standing history of atrial ectopy who was incidentally found to be in atrial flutter due to a new, rapidly growing cardiac rhabdomyoma impacting ventricular function. The boy was later confirmed with further investigation and TSC1 gene test to have TSC. DISCUSSION: Cardiac Rhabdomyoma does not always present in the infantile period. Any ongoing or new cardiac concern in patient with TSC, even if seemingly minor, should warrant more frequent cardiac evaluation and investigation.