Primary retroperitoneal benign mucinous cystadenoma in a male

Introduction: Retroperitoneal mucinous cystadenoma is extremely rare, prevailing specifically in female gender, with unclear histogenesis. Only three cases concerning male patients have been reported. Case Report: We report a case of a 75-year-old male presented with right flank pain and a palpable mass. An abdominal computed tomography scan revealed a retroperitoneal tumor resulting after the histological examination to a primary retroperitoneal mucinous cystadenoma. Conclusion: This is the fourth case of primary retroperitoneal mucinous cystadenoma of benign type in a male reported in literature. Several hypotheses may explain the histogenesis of this pathological process. Radical resection is the treatment of choice.