Epithelioid trophoblastic tumor: a clinicopathological and immunohistochemical study of seven cases.

The objective of this study is to evaluate the clinicopathological features and immunohistochemical characteristics of epithelioid trophoblastic tumor (ETT). Seven cases of epithelioid trophoblastic tumor treated in the Women's Hospital of Zhejiang University from 2004 September to 2008 December were retrospectively analyzed. Immunohistochemical study was performed. The most common presenting symptom was vaginal bleeding. Four patients had prior evidence of molar pregnancy and three patients presented with metastases. Mean age at diagnosis was 34.7 years. Mean pregnancy interval was 3.39 years. Human chorionic gonadotropin levels were 33.25-174315.5 IU/l. One case died from metastasis in lungs. The remaining six patients survived without recurrence. Immunohistochemistry revealed diffusely positive for CK18, and focally positive for β-hCG, HPL, Mel-CAM (CD146) and inhibin-alpha. Nuclear staining of Ki67 and p63 were seen. The confirmation of epithelioid trophoblastic tumor diagnosis is difficult before surgery. Surgical intervention is the recommended primary treatment.