Malignant germ cell tumor of ovary (ORPHA:35807)
Malignant germ cell tumor of ovary is a rare ovarian cancer arising from germ cells in the ovary, frequently unilateral at diagnosis which characteristically presents during adolescence with pelvic mass, fever, vaginal bleeding and acute abdomen.
Epidemiology
The annual incidence is 1/200000 females in Europe. Ovarian germ-cell tumors represent 15-20% of all ovarian tumors, 3% of which are malignant.
Clinical description
Malignant germ cell tumor of ovary is almost always unilateral at diagnosis (except malignant dysgerminomatous germ cell tumor, which can be bilateral in 10 to 15% cases). It usually presents during adolescence with symptoms of abdominal pain, pelvic mass, fever and vaginal bleeding. In about 10% of tumors the mass may grow rapidly, resulting in acute abdomen due to capsular distension, necrosis, hemorrhage, rupture or torsion. Certain subtypes may occasionally be associated with isosexual precocity, dysgenetic gonads, virilization, hyperthyroidism or carcinoid syndrome. Malignant germ cell tumor of ovary comprises the following histological subtypes: malignant dysgerminomatous germ cell tumor (most frequent form), malignant non dysgerminomatous germ cell tumor (yolk sac tumor, embryonal carcinoma, mixed germ cell tumor), primary non-gestational choriocarcinoma of ovary and malignant teratoma of ovary.
Etiology
They are rapidly growing neoplasms that arise from germ cells in the ovary.
Diagnostic methods
Diagnosis relies on clinical findings, serum tumor markers and imaging. Imaging includes pelvic ultrasonography and computed tomography of abdomen and pelvis (if extra ovarian metastasis is suspected) and chest X-ray (to detect metastasis to lung and mediastinum). Dosage of human chorionic gonadotropin (hCG), lactate dehydrogenase (LDH) and alpha fetoprotein (alpha-FP) also contribute to the diagnosis, the prognosis and follow-up of the disease. 12 p isochromosome (i(12p)) and chromosome 12 over-representation are observed, in non teratomatous ovarian germ cell tumors while pure teratomas lack i(12p). Diagnosis is only confirmed histologically after laparotomy or laparoscopy.
Differential diagnosis
Differential diagnoses include the less common malignant ovarian sex cord-stromal tumor, small cell carcinomas of the ovary (see these terms) and ovarian involvement of non-gonadal tumors.
Management and treatment
Malignant germ cell tumor of ovary shows excellent sensitivity to platinum. Young women with tumor confined to a single ovary are treated with fertility sparing surgery (unilateral salphingo-oopherectomy with preservation of uterus and contralateral ovary), followed by careful surgical staging with appropriate adjuvant chemotherapy usually comprising of bleomycin, etoposide and cisplatin for stage I tumor (except pure dysgerminoma). In women with advanced disease, preservation of reproductive function is still possible particularly if the contralateral ovary is normal. Paclitaxel and ifosfamide can also be used in case of relapse or resistance to cisplatin.
Prognosis
When treated promptly and appropriately, these tumors have excellent prognosis with return of normal menstrual function and fertility rates and no increase in teratogenicity.

                            Last update: 
                            September 2014


                            - Expert reviewer(s): 
                            Pr Mojgan DEVOUASSOUX  - Pr Isabelle RAY-COQUARD