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.