Nonepithelial Ovarian Malignancies

Abstract

Overview Compared with epithelial ovarian cancers, nonepithelial ovarian tumors are uncommon, constituting <10% of all ovarian malignancies. They include germ cell malignancies, sex‐cord–stromal tumors, carcinomas metastatic to the ovary, and a variety of extremely rare ovarian cancers, including sarcomas and lipoid cell tumors. Although there are many similarities in the presentation, evaluation, and management of patients, these tumors also have unique features that require special approaches to management. Germ cell malignancies are derived from primordial germ cells of the ovary and can be distinguished by histotype and expression of the biomarkers alpha‐fetoprotein (AFP) and/or human chorionic gonadotropin (hCG). They include dysgerminomas (AFP−hCG−), embryonal carcinomas (AFP+hCG+), immature teratomas (AFP−hCG−), endodermal sinus (yolk sac) tumors (AFP+hCG−), and ovarian choriocarcinomas (AFP−hCG+). Germ cell tumors occur in premenarchal girls and young women, grow rapidly, and can present with a symptomatic pelvic mass. As preservation of fertility is often an important priority, unilateral salpingo‐oophorectomy can often be performed followed by adjuvant platinum‐based therapy. Among the germ cell tumors, dysgerminomas can be bilateral in 10–15% of cases and are associated with gonadal dysgenesis in 5% of cases. Metastatic germ cell cancers can be quite sensitive to chemotherapy and the long‐term survival rate is high, even in advanced stages. At some institutions, young patients with stage IA germ cell tumors are followed carefully after resection and chemotherapy given only if there is recurrence with excellent outcomes. Sex‐Cord‐Stromal tumors include Granulosa‐Stromal tumors, Juvenile Granulosa tumors, and Sertoli–Leydig cell tumors. Granulosa‐Stromal tumors can occur at all ages and produce estrogen resulting in pseudoprecocious puberty in a small fraction of girls, amenorrhea in pre‐menopausal women, and endometrial hyperplasia in postmenopausal adults. Granulosa‐Stromal tumors are indolent and often confined to one ovary where surgery can cure stage I disease in more than 75% of cases. Adjuvant chemotherapy is generally not given after complete resection. Late recurrence has, however, been observed. Persistent or recurrent disease has responded to platinum based and hormonal therapy, including progestational agents, luteinizing hormone‐releasing hormone agonists, and aromatase inhibitors. Inhibin B has been a useful biomarker. Sertoli–Leydig cell tumors generally present in the third or fourth decade, produce androgens, and induce virilization in more than 70% of patients. As many Sertoli–Leydig cell tumors are in early stage and rarely bilateral, unilateral salpingo‐oophorectomy is often performed with 70–90% 5‐year survival.