Epithelioid trophoblastic tumor coexisting with choriocarcinoma around an abdominal wall cesarean scar: a case report and review of the literature

Background Mixed gestational trophoblastic neoplasms are extremely rare and comprise a group of fetal trophoblastic tumors including choriocarcinomas, epithelioid trophoblastic tumors, and placental site trophoblastic tumors. We present a case of a patient with extrauterine mixed gestational trophoblastic neoplasm adjacent to the abdominal wall cesarean scar. On the basis of a literature review, this type of case has never been reported before due to the unique lesion location and low incidence. Case presentation Our patient was a 39-year-old Chinese woman who had a history of two cesarean sections and one miscarriage. She had a recurrent anterior abdominal wall mass around her cesarean scar, and the mass was initially suspected of being choriocarcinoma of unknown origin. The patient had concomitant negative or mildly increased serum β-human chorionic gonadotropin at follow-up and no abnormal vaginal bleeding or abdominal pain. However, she underwent local excision twice and had two courses of chemotherapy with an etoposide and cisplatin regimen. She finally opted for exploratory laparotomy with abdominal wall lesion removal, subtotal hysterectomy, bilateral salpingectomy, and left ovarian cyst resection, which showed the abdominal wall lesion, whose components were revealed by microscopy and immunohistochemical staining to be approximately 90% epithelioid trophoblastic tumors and 10% choriocarcinomas from a solely extrauterine mixed gestational trophoblastic neoplasm around an abdominal wall cesarean scar. Conclusions It is worth noting whether epithelioid trophoblastic tumor exists in the setting of persistent positive low-level β-human chorionic gonadotropin. More studies are required to provide mechanistic insights into these mixed gestational trophoblastic neoplasms.