Figure 4b. Dysgerminoma of the ovary in a 31-year-old woman with fever and abdominal pain. (a) Sagittal T2-weighted MR image shows a large, lobulated solid mass in the pelvis and lower abdomen. Fibrovascular septa are seen as low-signal-intensity bands (arrows). (b) Sagittal contrast-enhanced T1-weighted MR image shows clear enhancement of the septa (arrows). (c) Photomicrograph (original magnification, x400; hematoxylin-eosin [H-E] stain) shows that the tumor is composed of large, round cells containing clear cytoplasm and irregularly flattened nuclei. (d) Photomicrograph (original magnification, x40; H-E stain) shows that the clusters of tumor cells are divided by fibrous septa, which include lymphocytes.