Figure 15c. Mature teratoma of the anterior mediastinum in a 29-year-old woman with no symptoms. A mediastinal mass was found at chest radiography. (a, b) Contrast-enhanced CT scans (a obtained cephalad to b) show a huge anterior mediastinal mass protruding into an interlobular fissure of the left lung. No calcification is seen in this case. (c) Photomicrograph (original magnification, x200; H-E stain) shows that the tumor contains a liquid-like pancreatic juice produced by mature pancreatic glands within the tumor.