Fast-growing immature ovarian teratoma during pregnancy: a case report and a review of the literature

Abstract Background Immature ovarian teratoma is one of the three common malignant ovarian germ cell tumors. However, immature ovarian teratoma in pregnancy is very rare. Due to the rare occurrence, there is little evidence regarding its diagnosis, optimal management, and prognosis. Hence, we present a case of immature teratoma diagnosed during pregnancy, and analyze its clinicopathological features, management and prognosis. Case presentation A 28-year-old woman underwent a sonographic examination revealed no abnormality in the bilateral adnexal area before 29 weeks gestational age (WGA). At 29 WGA, ultrasound demonstrated a 9.7 × 8.5 × 6.4 cm complex structure in the left adnexal area. At 30 WGA, repeated ultrasound revealed rapid growth of tumor mass, measuring 25.0 × 15.0 × 13.7 cm. An elective cesarean section combined with exploratory laparotomy was performed at 33 WGA. Intraoperative frozen pathological examination suggested left ovarian immature teratoma. Then, she underwent a complete staging surgery. Subsequently, the patient received 4 cycles of bleomycin-etoposide-cisplatin (BEP) chemotherapy. After 18 months of follow-up, there is no sign of tumor recurrence till now. Conclusions This case report suggests that the benefits and risks of timely treatment for patients and fetuses should be fully assessed by a multidisciplinary team. The early diagnosis, the timing of surgery and chemotherapy, the choice of chemotherapy for BEP will determine the prognosis. Surgery and combination chemotherapy with BEP play an important role in the treatment of immature teratomas in pregnancy, and could gain successful and satisfactory outcomes for mother and fetus.