Cysts of the mesentery, retroperitoneum and omentum are rare. We present a patient with a mucinous cystadenoma in the mesentery of the right hemicolon. The exact aetiology of these cysts at the aforementioned sites is still unclear. Adenocarcinomas can arise in mucinous cystadenomas. Therefore, in our opinion, to prevent spillage the right approach is to primarily perform a laparatomy instead of attempting to remove these lesions laparoscopically, even if clinical and radiological signs of malignancy are absent.