Abstract
BACKGROUND: Somatically derived ovarian yolk sac tumors (SD-YSTs) in postmenopausal women are rare and typically present with advanced-stage disease, often carrying a poor prognosis. CASE: We describe a 74-year-old woman with stage IIIB SD-YST who underwent complete surgical resection followed by cisplatin-etoposide chemotherapy, with bleomycin omitted due to frailty. Chemotherapy scheduling was modified in real time according to alpha-fetoprotein (AFP) kinetics, with treatment intervals shortened from 21 to 14 days after AFP levels rose between early cycles. Despite dose reductions due to thrombocytopenia, AFP levels normalized after cycle 3, and treatment was discontinued after cycle 4. OUTCOME: The patient has remained disease-free for over five years with ongoing surveillance. CONCLUSION: This case underscores the potential for long-term remission in SD-YST with platinum-based therapy, even when standard regimens require modification for older or frail patients. It highlights the value of biomarker-guided treatment adjustments to optimize chemotherapy timing in rare ovarian malignancies.