Placental Site Trophoblastic Tumor: A Distinct Entity of Gestational Trophoblastic Disease Experience from a Tertiary Referral Center in Hong Kong.

Objective: To review the clinical and pathological characteristics of patients with placental site trophoblastic tumor (PS TT) managed in a tertiary referral center in Hong Kong.

Study Design: Patients with a diagnosis of PSTT from 1995 to 2012 were identified from a computer database. Clinical and patho- logical data were obtained from medical records and the electronic database.

Results: Ten patients with PSTT were identified. Only 4 patients (40%) had disease confined to the uterus at presentation (Stage I). The most common site of metastasis was the lung. Four patients had pretreatment serum hCG levels <1,000 IU/L, and all of them had disease 'confined to the uterus. Of the 4 patients with Stage I disease 3 had hysterectomy only and 1 had both hysterectomy and chemotherapy. All 4 patients achieved complete remission; although 1 of them had a recurrence successfully treated with che- motherapy. For patients with Stage III/IV disease most of them had both hysterectomy and chemotherapy. Only 1 patient (20%) was alive without evidence of disease.

Conclusion: Patients with Stage I disease have excellent prognosis after hysterectomy, and adjuvant treatment is not recommended. A low pretreatment serum hCG level (<1,000 IU/L) was a good predictor of early stage disease. The prognosis for patients with metastatic disease was poor despite surgery and com- bination chemotherapy.