Epithelioid trophoblastic tumor diagnosed during a thorough examination of recurrent implantation failure: A case report

We describe an exceptionally rare case of epithelioid trophoblastic tumor (ETT) in a patient with recurrent implantation failure (RIF). A 38-year-old Japanese woman, gravida 1, para 1, was diagnosed with RIF following three unsuccessful cryopreserved morphologically good embryo transfers with hormone replacement cycles after thawing. She underwent hysteroscopy and endometrial biopsy to exclude chronic endometritis but was referred because ETT was strongly suspected. Following a preoperative diagnosis of stage I ETT, she underwent laparoscopic total hysterectomy and bilateral salpingo-oophorectomy. A yellowish elevated lesion was observed in the lower uterine body. Immunohistochemical staining was negative for human chorionic gonadotropin and human placental lactogen and positive for p63, with a Ki-67 proliferation index of >10%. She was diagnosed with stage I ETT, but postoperative chemotherapy was not administered because of the lesion location and occurrence within 48 months of the prior term delivery. She had no recurrence at 24 months postoperatively.