[Obstruction of the upper urinary tract caused by a malignant retrovesicular schwannoma. Therapeutic strategy].

We present a case of malignant Schwannoma (MS) of uncommon, retroperitoneal and retrovesical localization in a 42-year-old male, which provoked bilateral ureteral obstruction as a urological manifestation. We show our therapeutic strategy by means of a schedule of systemic neoadjuvant chemotherapy with vincristine, adriamycin, cyclophosphamide, decarbacine combined with exeresis and urinary continuity reconstruction surgery. We point out that it is a low incidence but highly aggressive tumour and that treatment continues to be local radical excision, whilst chemotherapy probably continues to have little value.