Placental site trophoblastic tumor (PSTT) is a very rare variant of gestational trophoblastic tumor. It can occur after normal termination of pregnancy or spontaneous abortion and ectopic or molar pregnancy. There is a wide range of clinical manifestations from a benign condition to an aggressive disease with fatal outcome. One of the most important characteristics of PSTT, unlike other forms of gestational trophoblastic diseases (GTD) is the presence of low beta-subunit of human chorionic gonadotropin (β-hCG) levels because it is a neoplastic proliferation of intermediate trophoblastic cells. However, human placental lactogen (hPL) is increased on histologic section and in the serum of patients too. We present a case of PSTT and discuss the differential diagnosis in order to further familiarize physicians with the diagnosis and treatment of this disease. It has a varied clinical spectrum and usually presents with irregular vaginal bleeding or amenorrhea. Diagnosis is confirmed by dilatation and curettage (D and C) and hysterectomy. Because chemotherapy is not effective, surgery is the cornerstone of treatment. This case is presented because it is a rare neoplasm with different treatments and it should be differentiated from molar pregnancy.
Keywords: Placental Site Trophoblastic Tumor; Ultrasound.