Locally Advanced Invasive Mole in the Presence of Low Serum β-hCG: A Case Report

Invasive mole is one of the most common forms of gestational trophoblastic neoplasia (GTN), characterized by hydropic chorionic villi with trophoblastic proliferation invading the myometrium. Although it usually develops after complete hydatidiform mole, occurrence following partial hydatidiform mole is uncommon. Delayed follow-up and inadequate β-human chorionic gonadotropin (β-hCG) surveillance may contribute to disease progression and severe complications.

A 34-year-old woman para 2 abortus 1, presented with massive vaginal bleeding and hypovolemic shock six months after evacuation of a partial hydatidiform mole. Initial pre-evacuation β-hCG level was 1183002 mIU/mL. Due to financial constraints and inactive health insurance, post-evacuation follow-up was delayed. Serial β-hCG levels declined but remained persistently elevated for more than six months. The patient experienced continuous vaginal spotting and was diagnosed with stage I low-risk gestational trophoblastic neoplasia with a FIGO prognostic score of 4. Two weeks prior to the onset of massive bleeding, the patient had received the first cycle of single-agent methotrexate chemotherapy.Doppler ultrasonography demonstrated markedly increased myometrial vascularity suggestive of invasive mole. Despite blood transfusion, antifibrinolytic therapy, and initiation of single-agent methotrexate chemotherapy, severe vaginal bleeding persisted, resulting in profound anemia (hemoglobin 6.7 g/dL). Emergency total hysterectomy with bilateral salpingectomy was performed due to life-threatening hemorrhage. Histopathological examination confirmed invasive mole with trophoblastic invasion extending into the parametrium. No distant metastases were identified.

Invasive mole following partial hydatidiform mole is rare but may lead to severe hemorrhagic complications when diagnosis and follow-up are delayed. Persistent elevation of β-hCG and abnormal uterine bleeding after molar evacuation should prompt early evaluation for gestational trophoblastic neoplasia. Multidisciplinary management, including chemotherapy, hemodynamic stabilization, and surgical intervention when indicated, is essential to achieve favorable outcomes.