Metastatic Epithelioid Trophoblastic Tumor Following Incomplete Methotrexate Therapy for Ectopic Pregnancy: A Case Report and Multimodal Management

Gestational trophoblastic neoplasia (GTN) comprises a spectrum of rare placental trophoblastic malignancies, including choriocarcinoma, placental site trophoblastic tumor, and the particularly uncommon epithelioid trophoblastic tumor (ETT). Unlike other GTN subtypes, ETT arises from chorionic-type intermediate trophoblasts and is characterized by relative resistance to chemotherapy, often necessitating primary surgical management. We report the case of a 33-year-old G6P5E1 woman with prior methotrexate treatment for suspected ectopic pregnancy who presented one year later with persistent abnormal uterine bleeding and markedly elevated serum β-human chorionic gonadotropin (β-hCG) of 36,477 IU/L. Imaging revealed a large uterine mass with multiple pulmonary nodules. Her β-hCG tumor marker was 177 IU/L, raising suspicion for trophoblastic neoplasm despite inconclusive initial curettage findings. Based on the International Federation of Gynecology and Obstetrics (FIGO) 2000 staging system and World Health Organization (WHO) prognostic scoring system, she was classified as FIGO Stage III with a WHO score of 9 (high-risk GTN). Total laparoscopic hysterectomy with bilateral salpingectomy confirmed metastatic ETT. Multi-agent chemotherapy with EMA-EP (etoposide, methotrexate, actinomycin-D, etoposide, and cisplatin) was initiated, resulting in a marked decline in β-hCG. The patient remains under ongoing multidisciplinary monitoring. This case highlights the diagnostic challenges of ETT in the setting of atypical β-hCG levels, its metastatic potential, relative chemoresistance, and the importance of early histopathologic confirmation and individualized management guided by FIGO staging and WHO prognostic scoring to optimize outcomes.