Female reproductive organ tumors commonly occur in the uterus of adult and postmenopausal women, but rarely in the extra-uterine of children and adolescents. Especially, benign tumor recurrence and transformation into malignant tumor with metastasis, is extremely rare. We report a special case of a girl who had been diagnosed as mucinous cystadenoma for the first time, recurred as high-grade adenosarcoma after the first operation, and developed distant metastasis after the second operation and chemotherapy. The clinic history, imaging and pathology of the case are very characteristic, and require us to find more rational therapeutic methods.
