Rationale: There is little knowledge regarding mullerian adenosarcoma and its metastasizing pattern.

Aim: Our objective was to evaluate the impact on the prognostic of the patient brought by tumor metastasizing to the retroperitoneum, to analyze the particularities of the treatment in such cases and to bring a significant change in the early therapeutic attitude to mullerian adenosarcomas.

Methods and results: We present a first case report of a hypervascularized retroperitoneal metastasis from an initial low-grade uterine adenosarcoma. The presence of such a metastasis brought the worst prognostic factor to the patient.

Conclusions: We consider that in front of a macroscopic polypoid mass there should be an active change in the diagnosis and in the therapeutic attitude. The frequent confusion between similar histopathological entities with different aggressiveness states and specific treatment responses, the poor outcome at advanced tumor stages, frequently in young patients, should trigger a universal remodeling in approaching these tumors.