Background: The most common clinical types of gestational trophoblastic neoplasia are invasive hydatidiform mole and choriocarcinoma, which can be diagnosed without pathology, and be cured by chemotherapy. Epithelial trophoblastic tumor, a rare type of gestational trophoblastic neoplasia, does not exhibit precise clinical manifestations upon auxiliary examinations. Therefore, since epithelial trophoblastic tumors are prone to misdiagnoses and missed diagnoses, their diagnosis have to be confirmed through pathology and immunohistochemistry. Case: We describe a case of a 37-year-old woman that had been misdiagnosed at a local hospital after she had presented with irregular vaginal bleeding and elevated human chorionic gonadotropin. The initial diagnosis was ectopic pregnancy and she was subjected to left salpingectomy, however, after treatment, there was no significant drop in human chorionic gonadotropin. Later, she was diagnosed with gestational trophoblastic neoplasia and was treated with multiple chemotherapy and hysterectomy. However, after treatment, her human chorionic gonadotropin was found to repeatedly fluctuate. Eventually, pathological examination of a resected lung lesion confirmed the presence of epithelial trophoblastic tumors. Conclusions: Epithelial trophoblastic tumor is an intermediate trophoblastic tumor that is not sensitive to conventional chemotherapy. Surgical resection is the recommended therapeutic option. Gestational trophoblastic neoplasia patients presenting with persistently low levels of human chorionic gonadotropin and resistance to conventional chemotherapy should, therefore, be considered for early surgical resection, or tissue biopsy to pathologically confirm the diagnosis and inform treatment options.