A cardiac mass revealing a thoracic neuroblastoma in a four-years- old: a case report

Abstract Neuroblastoma, an embryonal malignant tumor originating from neuroblasts within the sympathetic nervous system, is the third most prevalent pediatric malignancy, following leukemias and central nervous system tumors. The primary sites of metastases from neuroblastoma are the bone marrow, bones, and lymph nodes. Cardiac extension is an exceptionally rare occurrence. We report the case of a four-year-old child, with no prior medical history of cardiopathy, who had been experiencing exertional dyspnea for a few months leading to his admission. The patient presented to the pediatric emergency department for shortness of breath, chest pain, and fever.The clinical findings were: polypnea, signs of respiratory distress, bilateral jugular vein distention, and a systolic heart murmur at all the cardiac auscultation sites. A chest X-ray showed cardiomegaly and alveolar edema. Echocardiography revealed a large atrial septal defect with right heart enlargement, severe pulmonary hypertension, and an echogenic mobile lesion in the left atrium. Further investigations revealed a large left posterior mediastinal mass with calcifications extending to the left atrium. A biopsy was performed and histopathology of the mediastinal mass revealed neuroblastoma. The intracardiac extension of tumors in the pediatric population is rare. Thoracic and cardiac imagery can be used to characterize the mass further and adapt treatment. To the best of our knowledge, this is the first published case of a posterior mediastinal neuroblastoma with direct intracardiac extension.