NFS-09. A rare case of a large cardiac mass in a patient with neurofibromatosis type I (NF1)

Background Neurofibromatosis type I (NF1) is a cancer predisposition with multisystem involvement. Cardiac neurofibromas in the setting of NF1 are extremely rare with sporadic case reports. Case Herein, we present a 15-year-old female with neurofibromatosis type I (NF1 c.3306delA) who was found to have a large right atrial mass on echocardiogram further confirmed on cardiac MRI as a part of work-up for palpitations that started several years ago. Cardiac examination revealed a regular rate and rhythm. Auscultation revealed a normal S2. There were no clicks, rubs or gallops and the precordium was quiet. There were no murmurs. Results A 15 lead EKG demonstrated sinus rhythm with occasional premature atrial complexes (PACs) and a heart rate of 72 bpm. The corrected QT interval was 450 msec. An echocardiogram demonstrated a large echogenic mass in the posterior region of the right atrium near the right AV groove that appeared well circumscribed. It measured 6.0 X 3.3 X 3.2 cm in size and was non-obstructive. There was otherwise normal cardiac anatomy with normal biventricular size and function. These findings were further confirmed with a cardiac MRI where this mass appeared iso to hypointense on T1 weighted images, hyperintense on T2 weighted images with no contrast enhancement. Radiographic differential included a neurofibroma versus an atrial myxoma. The cardiac mass is likely the reason for palpitations and her symptoms are thought to be secondary to atrial ectopy. She is currently on an ambulatory cardiac monitor detect these episodes. Discussion The cardiovascular system in NF1 patients has recently received significant attention leading to our knowledge about higher than expected frequency of congenital heart defects, however, cardiac masses are a rare occurrence without much literature on the characteristic radiographic findings. This case highlights the need for deeper understanding of the complex molecular pathways that lead to development of cardiac masses in patients with NF1.