Clinical characteristics and outcomes of extrauterine epithelioid trophoblastic tumors

Background Epithelioid trophoblastic tumor (ETT) derived from intermediate trophoblasts is one type of gestational trophoblastic neoplasia (GTN), and it accounts for less than 2% of all gestational trophoblastic diseases (GTD). Extrauterine ETT is extremely rare, and there is currently no consistent strategy for its treatment and management. Therefore, the aim of the study is to analyze and summarize the clinicopathologic features of extrauterine ETT with or without metastasis.