[Characteristics of rare ovarian tumors--possibilities of organ preservation].

Whereas 65-70% of ovarian malignancies are of the epithelial type, the occurrence rate of stromal tumors is of approx. 7% and that of germ cell tumors of approx. 15%. Stromal tumors are mostly of the granulosa cell type, whereas germ cell tumors occur mainly as dysgerminoma (occurrence 0.9-2%), endodermal sinus tumors, or teratoma. Organ preservation is discussed in relation to the characteristics of these special tumor types. Granulosa cell tumors, representing 70% of the tumors of the gonadal stroma, occur unilaterally in approx. 97% of cases. 10-year-survival in stage I is over 90%. In stages II and III a complete remission after chemotherapy (acc. to the PVB, VAC, or BEP protocol) may be achieved in approx. 60% of cases. Due to these characteristics organ preservation seems feasible. Since dysgerminoma represent the most common malignant germ cell tumor in children, adolescents and pregnant women (up to 17% of all dysgerminoma are diagnosed during pregnancy), the wish for organ preservation is the more understandable. However, bilaterality, occurring in 20% of cases, has to be considered. Especially in large tumors lymphatic metastases also have to be taken into account. In cases of endodermal sinus tumors and teratoma, overall survival, mainly in patients with advanced disease, depends on the response to an aggressive chemotherapy. Preconditions for organ preservation are the patients' urgent childbearing desire, their information concerning the 5-7% risk of recurrence, an adequate oncologic postoperative care and optimally, after delivery, removal of the contralateral ovary and re-staging. The operative procedure requires removal of the corresponding adnexa, wedge dissection of the contralateral ovary, omentectomy, and depending on the histological tumor type a pelvic, possibly paraaortal lymph node dissection. No generally accepted standards are available for organ preserving surgery of stromal tumors, especially of the granulosa cell type. Prognosis is essentially influenced by a possible rupture being present, tumor size, cellular atypia, and the mitotic index. If one takes into consideration the possibility of lymph node metastases, at least a pelvic lymph node dissection should be recommended. In cases of metastases additionally a chemotherapy (VAC protocol) is indicated. Among germ cell tumors, dysgerminoma and non-dysgerminoma are treated differently. Non-dysgerminoma are endodermal sinus tumors, teratoma, embryonal carcinoma and mixed forms. For both groups operative management may aim at tumor reduction and in principle organ preservation. Whereas for dysgerminoma an adjuvant radiation therapy is feasible, in cases of non-dysgerminoma the response to a chemotherapy is the only factor influencing prognosis. Chemotherapy as adjuvant treatment is not indicated for pure dysgerminoma stage Ia, and pure solid teratoma stage Ia Gl. For all other dysgerminoma adjuvant chemotherapy, VAC protocol, and chemotherapy according the the BEP protocol for non-dysgerminoma is recommended. In cases of metastatic spread, in both groups an aggressive chemotherapy (BEP protocol) is most commonly performed.