LAUSR

Rationale: Yolk sac tumors (YSTs) are malignant germ cell tumors that secrete alpha-fetoprotein (AFP). These tumors commonly develop in infants, young children, and young women and often originate in the gonads. Primary endometrial YST is a very rare malignancy, and a primary endometrial YST in the absence of abnormal AFP levels is even rarer. Patient concerns: A 38-year-old woman presented with the chief complaint of prolonged menstruation and increased menstrual bleeding with a duration of more than 2 months. Diagnoses: Postoperative pathology confirmed a diagnosis of endometrial YST with metastasis to the greater omentum (stage IVB). Interventions: The patient underwent a laparoscopic extrafascial hysterectomy, bilateral adnexectomy, pelvic lymphadenectomy, abdominal para-aortic lymphadenectomy, omentectomy, and appendectomy. Additionally, she received 6 courses of multidrug chemotherapy (bleomycin, etoposide, and cisplatin; BEP). Outcomes: After completing chemotherapy, the patient underwent regular follow-up examinations. No recurrence was noted during a 24-month follow-up period. Lessons: YST is mainly treated using surgery and chemotherapy, which may spare endocrine functions in young patients. The BEP regimen appears to be an effective postoperative chemotherapy regimen for patients with endometrial YST.