A rare case of pure non-gestational ovarian choriocarcinoma: Diagnostic mimicry and management strategies

ABSTRACT

Background: Non-gestational ovarian choriocarcinomas (NGOC) are rare, distinct, highly aggressive tumors, primarily affecting young women. It accounts for less than 0.6% of malignant ovarian germ cell tumors. It is associated with a poorer prognosis compared to gestational choriocarcinoma.

Case Presentation: A 36-year-old woman (P2L2) presented with intermittent heavy menstrual bleeding for the past three months. The urinary pregnancy test was positive. On abdominal examination, a solid mass consistent with 20-weeks gravid uterus was palpated in right iliac fossa. Bimanual pelvic examination revealed uterus deviated to the left and large (~12 × 10 cm) predominantly solid mass arising from right adnexa, adherent to the uterus. A mobile cystic mass (6 × 5 cm) was palpated in the left fornix. Ultrasonography showed normal-sized uterus with no gestational sac and a well-defined, solid-cystic right adnexal mass (10.2 × 7.8 × 7.8 cm) with vascularized solid areas and hemorrhage, initially suggesting an ectopic pregnancy. Serum β-hCG was markedly elevated (262,809 mIU/mL; normal level <5.0 mIU/mL). Magnetic Resonance Imaging (MRI) and Contrast-enhanced Computed Tomography (CECT) revealed right ovarian germ cell tumor, likely choriocarcinoma, without evidence of metastatic disease. On staging laparotomy, hemorrhagic right tubo-ovarian mass (8.5 × 8 × 7 cm) and left ovarian serous cystadenoma (8 × 7 × 3.5 cm) were identified. Histopathology and genomic studies confirmed stage IA1 NGOC. Patient completed two cycles of adjuvant chemotherapy with Bleomycin, Etoposide, Cisplatin, achieving complete response (β-hCG <5 mIU/mL), and is following up with serial β-hCG monitoring and CT scans for two years.

Conclusions: NGOC closely mimics ectopic pregnancy and gestational trophoblastic disease and requires early diagnosis with prompt surgical and chemotherapeutic intervention to optimize outcomes.