[Trophoblastic tumor on the placenta. Diagnosis, prognostic factors, treatments].

Previously known under other terms, placenta site trophoblastic tumor (PSTT) is a specific entity among trophoblastic diseases. Outcome is highly variable depending on the clinical course which may range from benign disease to high-grade malignancy. Histology and biology, including mitotic count, the degree of tumor invasion, the process of necrosis within the tumor and plasma beta-hCG level, provide important indications for prognosis. Survival without recurrence can be achieved with wide surgical excision. Complete hysterectomy with or without bilateral salpingooophorectomy is required. Chemotherapy and radiotherapy have no effect. In case of desired pregnancy, the acceptability of conservative treatment must be judged on the basis of hysteroscopy with MRI or endoscopic sonography findings. In cases with good prognosis, conservative management may be proposed with hysteroresection for an endouterine tumor or complete resection of the PSTT, the uterus remaining in situ during the laparostomy. Obstetrical prognosis, still to be determined, depends on the validity, feasability and fertility rate after such procedures. Curettage must be abandoned.