Critical obstruction of the right ventricular outflow tract by a primary hemangioendothelioma in a seven month old

A 7-month-old presented with failure to thrive and a murmur. Echocardiograp hy demonstrated a large mass in the right ventricular outflow tract, extend ing through the pulmonary valve. During anaesthetic induction this caused c ritical obstruction of the outflow tract and cardiac arrest. Pathological d iagnosis showed the lesion to be a primary hemangioendothelioma. Despite su rgical excision and steroid therapy, the mass continued to grow for a perio d of 8 weeks, but then began to regress spontaneously.