Gestational choriocarcinoma [GCC] is an uncommo trophoblastic neoplasm. In an extremely rare circumstance,
the GCC over the site of cesarean scar may occur. We reported a patient who presented with vaginal bleeding and rising betahCG level two weeks after treatment of abortion. Ultrasonography showed a small content located at lower part of uterus. Provisional diagnosis was a Cesarean scar pregnancy and the patient decided to have hysterectomy. Histopathologic examination reported small foci of choriocarcinoma at Cesarean scar. The diagnosis was stage I:3 choriocarcinoma. After surgical treatment, her beta-hCG level gradually declined to normal value. Without adjuvant treatment, she was doing well with no evidence of recurrent disease for 25 months after surgery. In conclusion, although it has been generally known that GCC usually occurs months to years after pregnancy, gestational trophoblastic disease cannot be overlooked in the case that is clinically suspicious. Surgical treatment might be effective without adjuvant chemotherapy in some selected cases; however, the beta-hCG level must be monitored closely.

Keywords: Gestation choriocarcinoma, Cesarean scar, Pregnancy, Trophoblastic neoplasm