Epithelioid trophoblastic tumor: A single institution case series at the New England Trophoblastic Disease Center

Epithelioid trophoblastic tumor (ETT) is a rare form of gestational trophoblastic neoplasm which is distinct based on its development from intermediate trophoblast cells and nodular growth pattern. The aim of this study is to describe a case series from a single institution with a review of the literature to better understand the clinical characteristics and outcomes for patients with ETT.

A retrospective review was performed using the IRB approved New England Trophoblastic Disease Center (NETDC) database from 1998 to 2014. Eight patients were identified of which seven had complete records. Follow-up data was obtained from the longitudinal medical records.

Four (57.1%) patients presented with vaginal bleeding and two (28.6%) patients were asymptomatic at presentation. Three (42.9%) patients had extrauterine disease. All three patients with extrauterine disease who received chemotherapy had stable or progressive disease at follow-up. Only two (29%) patients who presented with non-metastatic disease and underwent hysterectomy were alive with no evidence of disease. The mean interval following antecedent pregnancy was 104months. All patients with an interval >4years demonstrated stable or progressive disease despite intensive chemotherapy. Two patients with non-metastatic disease who declined hysterectomy developed stable or progressive disease despite chemotherapy.

This series highlights several features of ETT including the potential for asymptomatic presentation of extrauterine disease. The series also demonstrates chemoresistance, even with multi-agent therapy and a poor prognosis with extrauterine disease and an interval greater than 4years following the antecedent pregnancy suggesting that surgery remains critical in disease control.