Figure 10a. Intrapericardial teratoma. (a) Color Doppler US image through a fetal chest shows a large echogenic mass (straight arrow) adjacent to the heart. Note the extensive surrounding pericardial effusion (curved arrows). (b) Coronal T2-weighted image shows a mixed-signal-intensity mass (straight arrow) adjacent to the heart (curved arrow). The mass is surrounded by high-signal-intensity pericardial fluid. No normal lung parenchyma is identified. (c) Autopsy photograph obtained with the pericardium intact shows a massive effusion, with the pericardial sac essentially filling the entire thoracic cavity. (d) Autopsy photograph obtained with the pericardium removed reveals the large teratoma (straight arrow) anterior to the heart (curved arrow).