Deeper Understanding of Epithelioid Trophoblastic Tumor

Epithelioid trophoblastic tumor(ETT) is a rare type of gestational trophoblastic neoplasm(GTN), which originates from intermediate trophoblastic cells of chorionic-type. Its presentation is complex and diverse, making the diagnosis challenging. The diagnosis depends mainly on pathological diagnosis. Generally, ETT is a slow-growing malignant tumor, though some cases may have aggressive and fatal clinical courses involving multiple metastases, and demonstrate a greater malignant behavior compared to the placental site trophoblastic tumor(PSTT). Surgical resection remains the cornerstone of treatment. There is no standardized postoperative adjuvant chemotherapy regimen. Multifocal disease within the uterus, the presence of extra-uterine disease, an interval greater than 4 years from antecedent pregnancy, and high Ki-67 index may be markers of poor prognosis. At present, the behavior and clinical course of ETT are yet not fully understood. More cases and data of ETT should be collected to help guide diagnosis and management.