Primary omental yolk sac tumor
A 32-year-old woman was referred to this hospital because of developed low abdominal distension for a month. She got married at the age of 27 years and had no history of pregnancy. She had received diagnostic laparoscopy due to infertility in the past. Menstruation was regular with intervals of 26 days with moderate volume of menstrual fluid and duration.\nIn physical examination, a palpable mass with abdominal pain and tenderness was found in the right lower quadrant abdomen. CA-125 level was 364 U/mL (normal range, less than 35 U/mL). CA-19-9 level and carcinoembryonic antigen was in the normal range.\nMagnetic resonance imaging (MRI) showed a mass, about 22 ×16 × 8 cm3 in size with ascites and peritoneal seeding nodules (). Findings of intravenous pyelogram, bladder washing cytology, mammography, colonoscopy, and esophago-gastro-duodenoscopy were negative.\nExplorative laparotomy was performed and an omental mass, about 23 ×15 ×10 cm3 in size, occupying whole abdomino-pelvic cavity was noted. As frozen biopsy of omentum showed a poorly differentiated tumor though whether it was primary or metastatic was uncertain, total abdominal hysterectomy with bilateral salpingo-oophorectomy, bilateral pelvic lymph nodes dissection, paraaortic lymph nodes sampling, total omentectomy, and appendectomy were performed.\nHistopathological result of omental mass showed Schiller-Duval body and both ovaries were not involved (). Right ovary was diagnosed as endometriotic cyst and left ovary was hemorrhagic corpus luteal cyst. AFP level at the postoperative day 7 was high (11,576.67 IU/mL) (normal range, less than 7 IU/mL) though preoperative AFP was not measured.\nFrom the postoperative day 7, 6 cycles of postoperative adjuvant chemotherapy (bleomycin, etoposide, and cisplatin [BEP] regimen) with etoposide 100 mg/m2 and cisplatin 20 mg/m2, each cycle lasting 3 days in combination with 6 cycles of bleomycin 20 U/m2, each cycle lasting 1 day were performed every 3 weeks. In the follow-up after the first chemotherapy, AFP level was found to have decreased to 1,746.15 IU/mL (normal range, less than 7 IU/mL), and in the follow-up positron emission tomography-computed tomography (CT) at 1 month after the sixth chemotherapy, abnormal hypermetabolism suggestive of remnant tumor or metastasis was not observed and AFP level was normal with 2.04 IU/mL (normal range, less than 7 IU/mL). No recurrence was found during the 4-year outpatient follow-up by CT and AFP level.