Cardiac leiomyosarcoma of the right atrium in a teenager: Unusual manifestation with a lifetime history of atrial ectopic tachycardia

A 16-year-old girl presented with atrial fibrillation. Transesophageal echo cardiography revealed a right atria] leiomyosarcoma. Her past medical histo ry was remarkable for incessant atrial ectopic tachycardia (AET) beginning in early infancy and continuing throughout childhood and adolescence that w as refractive to medical and nonpharmacological treatment. After combined s urgical and medical therapy, normal sinus rhythm was restored and the patie nt is currently in complete remission with no recurrent symptoms or atria] arrhythmias at 31 months after surgery and 23 months after the discontinuat ion of chemotherapy, Atrial tachycardia may be the first, and for prolonged periods, the only manifestation of a cardiac tumor and should prompt thoro ugh investigation of its underlying morphological substrate.