Ovarian Dysgerminoma: Diagnosis and Treatment

Dysgerminoma is the female version of the male seminoma and is essentially comprised of immature germ cells.This ovarian tumor may grow rapidly, unlike the more common epithelial ovarian neoplasms, yet most patientspresent with stage IA disease (limited to one ovary).Evidence of bilateral ovarian involvement suggests the presence of a tumor with a propensity for involvement ofthe contralateral ovary. Patients typically present with one or more of the following signs and symptoms:Abdominal enlargement – From the mass itself, ascites, or bothAbdominal pain – From rupture or torsionThe diagnosis is made by histology at time of surgical excision. The diagnosis is strongly suggested preoperativelyby the presence of an adnexal mass on pelvic imaging.These tumors are staged according to the International Federation of Gynecology and Obstetrics (FIGO) stagingsystem for epithelial ovarian cancer. In brief, stage I disease is confined to the ovaries, stage II includes extensioninto other pelvic tissues, stage III refers to disease that has spread beyond the pelvis or to retroperitoneal lymphnodes but remains in the abdomen, and stage IV refers to the presence of distant metastasis or involvement ofliver parenchyma. Although dysgerminomas are relatively uncommon among all ovarian neoplasms (accountingfor only about 2 percent), they account for 32.8 percent of malignant OGCTs. The majority of cases (75 percent)arise in adolescents and young adults, in whom they account for about one-third of all ovarian malignantneoplasms.Because of their predilection for young women, they are one of the more common ovarian malignant neoplasmsdetected during pregnancy. Nevertheless, dysgerminoma can occur at any age; case reports have describedpatients with dysgerminoma between 7 months and 70 years of age. Although dysgerminomas are considered tobe malignant, the degree of histologic atypia is variable, and only about one-third behave aggressively.Dysgerminomas may develop within a gonadoblastoma (a benign or in situ germ cell ovarian neoplasm composedof germ cells and sex cord stroma) in phenotypic females who have a Y chromosome. Included in this group arepatients with pure gonadal dysgenesis 46XY, mixed gonadal dysgenesis 45X/46XY, or complete androgeninsensitivity (formerly called testicular feminization) 46XY.Dysgerminomas can contain syncytiotrophoblastic giant cells that produce placental alkaline phosphatase, andlactate dehydrogenase (LDH). Serial measurements of these markers can be useful for monitoring disease. Inaddition, 3 to 5 percent of dysgerminomas produce human chorionic gonadotropin (hCG). In general,dysgerminomas do not produce alpha fetoprotein (AFP), although borderline elevations (<16 ng/mL) are describedin case series, but most often in the setting of mixed germ cell tumors that contain a yolk sac element. 75% percent of women with dysgerminomas present with stage I disease; the contralateral ovary is involved in 10to 15 percent. Bilateral ovarian disease is more common with dysgerminoma than with any other malignant OGCT.Surgery is performed for definitive diagnosis, staging, and initial treatment. For a unilateral neoplasm confined tothe ovary without capsular involvement or rupture (stage IC), simple salpingo-oophorectomy is curative in over95 percent. In contrast to EOC, nodal involvement is more common with dysgerminoma. Therefore,lymphadenectomy is generally performed as part of the surgical procedure. Adjuvant chemotherapy isrecommended for most women after surgery. Exceptions to this include stage IA and IB dysgerminoma becausetheir outcomes are excellent following surgery alone.