Recurrent Inflammatory Myofibroblastic Tumor of the Heart

A previously healthy 15-year-old boy was admitted after 6 months of intermittent fevers, night sweats, and 9 kg weight loss. A systolic murmur was appreciated at the left upper sternal border. Laboratory data revealed elevated white blood cells (11 800/μL), erythrocyte sedimentation rate (75 mm/h), and C-reactive protein (10.5 mg/dL). The results of blood cultures were negative. Imaging demonstrated a hypermetabolic 2×2×4.5 cm pedunculated mass in the right ventricle, suggestive of a neoplasm with overlying thrombus (Figures 1A, 2A and 2B and online-only Data Supplement Movie I).Figure 1. Cardiac magnetic resonance imaging demonstrating the initial IMT originating from the interventricular septum near the right ventricular outflow tract ( A ) and the recurrent IMT near the tricuspid annulus ( B ). IMT indicates inflammatory myofibroblastic tumor.Figure 2. Transthoracic echocardiography before and after resection of the initial inflammatory myofibroblastic tumor. A and B , Preoperative images showed a large echogenic mass in the apex of the right ventricle extending superiorly through the right ventricular outflow tract. C and D , Postoperative echocardiography revealed no evidence of residual tumor. A4C indicates apical 4-chamber view; Ao, aorta; LA, left atrium; LV, left ventricle; PA, pulmonary artery; PSAX, parasternal short axis view; RA, right atrium; RV, right ventricle; RVOT, right ventricular outflow tract; Pre-op, preoperative; and Post-op, postoperative. Arrow denotes the tumor.At surgery, the mass was found to originate from the midportion of the interventricular septum and was covered with thrombus. …