Non-epithelial ovarian cancer: ESMO clinical recommendations for diagnosis, treatment and follow-up.

Non-epithelial malignancies of the ovary account for 10% of all ovarian cancers. Germ cell tumors (GCTs) are diagnosed principally in young subjects whereas sex cord stromal tumors (SCSTs) are more common in adult women. GCTs represent 5% of all ovarian neoplasms and 80% of preadolescent malignant ovarian tumors. Sex cord stromal tumors are rare neoplasms that account for 3–5 % of ovarian malignancies and for the majority are functioning tumors with clinical manifestations. The yearly adjusted incidence rate is 3.7/1000 000 and 2.1/1000 000 women for GCTs and SCSTs, respectively.