RESUMO
BACKGROUND: Retroperitoneal cystadenocarcinomas are rare lesions, the majority of cases presented as one-patient reports. METHODS: We present two cases of retroperitoneal cystadenocarcinoma, both in women of reproductive age: one with aggressive behavior, and the remaining case, with a more indolent clinical evolution. RESULTS: One case presented as pelvic tumor, was treated with surgical resection of the disease, but manifested with recurrent disease a few months later despite use of chemotherapy. The second case involved a patient with diagnosis of abdominal tumor; during laparotomy, a retroperitoneal tumor was found and was totally removed. At follow-up, the patient is disease-free with no other treatment. CONCLUSION: The behavior and treatment of retroperitoneal cystadenocarcinoma are controversial. We suggest aggressive surgery including radical hysterectomy and bilateral salpingoopherectomy with adjuvant chemotherapy in these cases.