Objectives The aim of this study was to evaluate the clinicopathologic features of placental site trophoblastic tumors (PSTTs) in Korea.

Methods/Materials Twenty patients given a diagnosis of PSTT in Korea (1990–2013) were evaluated retrospectively, including 14 patients identified through a literature review and 6 patients identified through a medical chart review of a single institution. The analysis included patient age, antecedent pregnancies, time since antecedent pregnancy, presenting symptoms, serum β-human chorionic gonadotropin level, International Federation of Gynecology and Obstetrics stage, treatment, outcome, and follow-up.

Results The mean age of the 20 patients was 32 years (range, 25–53 years). The antecedent pregnancies included 8 term pregnancies, 8 abortions, and 2 molar pregnancies. The time since the antecedent pregnancy was less than 1 year in 16 patients (80%). Nineteen patients (95%) presented with abnormal vaginal spotting or amenorrhea. Serum β-human chorionic gonadotropin levels ranged from normal to 13,480 mIU/mL, although most patients (80%) had a level less than 1000 mIU/mL. Seventeen patients (85%) presented with stage I disease. Ten patients (50%) underwent hysterectomy, and 14 patients (70%) were treated with chemotherapy with or without hysterectomy. In 11 evaluated patients, the median mitotic count index was 3.4 (0.4–10) per 10 high-power fields. The median follow-up time was 17 months (range, 1–68 months). There was no recurrence or death from disease.

Conclusions Korean patients with PSTT often have early-stage disease, which has a favorable prognosis even with fertility-preserving therapy. However, international studies are necessary to determine the optimal treatment and prognostic factors.