Placental site trophoblastic tumor (PSTT) with multiple metastases and extremely poor prognosis

Placental site trophoblastic tumor (PSTT) is a rare type of gestational trophoblastic disease. There is a wide clinical spectrum of presentation and behavior ranging from a benign condition to an aggressive disease with a fatal outcome. PSTT limited to the uterus is in a good prognosis group, but PSTT with metastasis is a lethal disease. We document a case of PSTT with multiple metastases and extremely poor prognosis. A 36-year-old woman had abnormal irregular vaginal bleeding 14 months after her third pregnancy and delivery. The mitotic count of the tumor cells was quite high (23/10 high-power fields). It would have been difficult to remove the tumor by surgery because of the tumor size and its invasion, so we suggested chemotherapy. We treated her with EMA/CO (etoposide, methotrexate, actinomycin-D, cyclophosphamide, vincristine) as a first-line regimen. During the sixth cycle of EMA/CO, the disease became drug-resistant and she died 8 months after the first symptom. This was a rare case among documented patients with PSTT with metastasis, with the patient having short-term survival (< 1 year). We conclude that a high mitotic count and atypical undifferentiated pathological features are significant poor prognostic factors for survival in PSTT.