An extremely rare primary non-gestational choriocarcinoma of the vagina: a case report.

Introduction and importance: Primary non-gestational choriocarcinoma (NGC) of the vagina is an exceedingly rare and aggressive malignancy originating from pluripotent germ cells, with very few cases documented in the literature. Differentiating it from gestational choriocarcinoma is crucial, as NGC exhibits poorer prognosis and reduced chemotherapy responsiveness. This case report highlights a unique presentation of vaginal NGC in a postmenopausal woman, emphasizing diagnostic complexities and therapeutic challenges. Case presentation: A 57-year-old postmenopausal woman (G3L2Ab1) with a history of two cesarean sections presented with 1 month of postmenopausal spotting. Clinical examination under anesthesia revealed a necrotic 4 cm vaginal mass on the left lateral wall. Imaging confirmed a solid heterogeneous vaginal mass, and serum beta-human chorionic gonadotropin (β-hCG) was elevated (198-209 mIU/mL). Histopathology and immunohistochemistry confirmed primary vaginal NGC. The patient underwent chemotherapy with the EMA-CO regimen. β-hCG levels normalized after the second cycle, and PET scan post-treatment showed no active lesions. Surgical intervention was deemed unnecessary. She remains disease-free under regular follow-up. Clinical discussion: This case underscores the importance of maintaining a high index of suspicion for choriocarcinoma in postmenopausal patients presenting with unexplained vaginal bleeding. Due to its rarity and nonspecific symptoms, primary vaginal NGC can be misdiagnosed. Despite its typical resistance to chemotherapy, the patient showed complete remission with EMA-CO, illustrating that early diagnosis and aggressive treatment may improve outcomes even in NGC cases. Conclusion: Primary vaginal NGC is a rare but timely diagnosis, appropriate confirmation and chemotherapy can result in favorable outcomes. Long-term surveillance is essential due to the potential for recurrence.