EP801\u2005Malignant ovarian mixed germ cell tumor: a case report of a rare combination

Abstract

Introduction/Background Ovarian malignant germ cell tumors (OGCT) derive from primordial germ cells of the ovary and arise primarily in young women between 10 and 30 years of age, representing 70% of ovarian neoplasms in this age group. Mixed cell types constitute about 29% of OGCT, following pure dysgerminomas (33%) and immature teratomas (39%), being the most reported combination that of dysgerminoma and endodermal sinus tumor. Methodology Hereby we present a rare combination of mixed cell OGCT, comprising both embrionic carcinoma and yolk sac tumor. Results A 26-year-old nulliparous woman presented on january 2019, diagnosed by a private gynecologist of left adnexal mass. On ultrasound, an heterogeneus left pelvic mass of 100*65 mm, with peripheric positive Doppler map and minimum ascites was reported. On preoperative work-up a left ovarian tumor without lymphatic or peritoneal extension showed on CT-scan, as well as elevated tumoral markers (BHCG=9402; AFP=5588, Ca 125=109,3; LDH=1279). Medium laparotomy was performed, followed by exploration of abdominal cavity, ascites sampling, left adnexectomy, partial omentectomy and biopsy of a right ovarian, apparently benignant, fibrotic mass. Pathological findings included ovarian benignant fibroma of the right ovary, negative omentum, positive preoperative cytology and left ovarian mixed cell OGCT, comprising 97% embrionic carcinoma and 3% yolk sac tumor, with focal capsular infiltration, 1C3 surgical stage. Postoperative tumoral markers decrease was monitorized, fertility sparing treatment was rejected and three courses of BEP adjuvant chemotherapy were given. No postoperative disorders were reported, third cycle was delayed due to moderate hepatotoxicity, and follow-up has shortly begun. Conclusion OGCT are a group of heterogeneous, sometimes highly malignant neoplasms, so suspiction must always arise in case of young women, presenting with rapidly growing solid pelvic mass. Early sugical intervention is mandatory, fertility sparing must be individually discussed and a thorough pathological examination must be performed, prior to evaluate eventual adjuvant therapies. Disclosure Nothing to disclose. Abstract EP801 Figure 1 Left pelvic mass of 100*65 mm, with peripheric positive Doppler map and minimum ascites Abstract EP801 Figure 2 Embrionic carcinoma on H-E; Alpha1Antitrypsine and AFP+ yolk sac tumor cells; HCG+ cells