The prognosis of dysgerminomas is excellent. Stage IA tumors (limited to one ovary or fallopian tube with intact capsule; no malignant cells in ascites or peritoneal washings) have 5-yr survival rates of greater than 95%. In advanced stage disease or recurrent tumors, the 5-yr survival is still 85%. Recurrences in the contralateral ovary are seen in 5-15% of cases, usually within 2 years. Other common sites for recurrence are peritoneal cavity and retroperitoneal lymph nodes. The features associated with greater likelihood of recurrence are tumor larger than 10 cm. and patient age younger than 20 years. The image shows sheets of polygonal tumor cells separated by delicate fibrous septa containing a few lymphocytes. Note the resemblance to a seminoma.