During routine neonatal examination of a healthy looking female infant on day 1 of life, a grade 2/6 ejection systolic murmur was audible at the left sternal border. Chest x ray and ECG were normal. An echocardiogram revealed a mass 8 mm in diameter in the left ventricular outflow tract (LVOT), with a pressure gradient of 25 mm Hg between the left ventricle and aorta by Doppler study. The mass was seen arising from the interventricular septum just below the aortic valve and there were two small masses at the right ventricular apex (panels A and B ; Ao, aorta; LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle; T, tumour mass). In view of the serious risk for embolic events or total obstruction and sudden death, the tumour mass was resected on the fifth day of life through a transaortic approach (right panel) under cardiopulmonary bypass and cardioplegic arrest. The postoperative period was uneventful and a repeat echocardiogram revealed no residual mass or aortic valve dysfunction. The LVOT was widely patent both anatomically and on Doppler study. Histopathological examination of the mass measuring 9 × 8 × 7 mm revealed it to be a rhabdomyoma. Examination of the fundus and ultrasonography of the head and abdomen of the neonate were normal. Since the majority of infants presenting with a cardiac rhabdomyoma develop tuberous sclerosis in later life, prolonged follow up is indicated.
Rhabdomyoma is the most common benign primary cardiac tumour in children and it may be single or multiple. Large tumours may present with arrhythmia, dysfunction of cardiac valves, pericardial effusion, non-immune hydrops fetalis, congestive heart failure, embolisation, and inflow/outflow obstruction. Tumour regression mostly occurs in the first two years of life. Surgery is recommended in the presence of obstruction or life threatening arrhythmias.