Cases Report And Literature Review Of Epithelioid Trophoblastic Tumor

Epithelioid Trophoblastic Tumor( ETT) is a kind of rare and unusual GTN, and it was firstly reported by Shih and Kurman in 1998. ETT is originated from chorionic intermeted trophoblast, and the pathogenesis remains unknown. ETT was mostly found in women of reproductive age. The average age was 36 years old (15～48yr). ETT was also reported in postmenopausal women. Abnormal vaginal bleeding is the most common symptom, and in a few patients, the firstly manifested symptoms are rised from metastatic lesions. Rare cases have no symptom. Like PSTT, serum HCG was elevated unlimitedly in ETT. Compared with choriocarcinoma, HCG level of ETT (<2500IU/L) is lower, and the highest reported HCG level of ETT was 12541IU/L. Usually, ETT is diagnosed by postoperation pathological study, and it is difficult to ascertain ETT before surgery. Immunohistochemistry study is helpful to the pathological diagnosis.Cytokeratin, EMA, E-adherin and EGFR are expressed in ETT. It is indicated that ETT is of epithelial origin. Surgerical management is mostly recommended in ETT. The role of chemotherapy in ETT is not clear yet. According to the present literatures, the prognosis of ETT is well. The biobehaviour of ETT is of benign characters resembling PSTT. It is less infiltrative than choriocarcinoma, and it's has a metastatic rate of 25% and a mortality of 10%.