Figure 10a. Mixed GCT of the anterior mediastinum in a 22-year-old man with dyspnea. Chest radiography indicated that the left thorax was filled with tumor tissue. (a) Coronal T2-weighted MR image shows a large, heterogeneous mediastinal mass that invades the left pleural cavity. The heart, great vessels, and left lung are markedly compressed (arrows). (b) Contrast-enhanced CT scan shows that most of the tumor appears solid, although a relatively large cystic component is seen (arrow). Surgical exploration was followed by chemotherapy. (c) Photomicrograph (original magnification, x400; H-E stain) shows a small amount of immature neural tissue. In addition, serum levels of human chorionic gonadotropin and 
-fetoprotein were very high at admission. The tumor was diagnosed as a mixed GCT that included an immature teratoma.