[Synchronous multiple carcinomas of the colon and rectum. Presentation of 18 cases and review of the literature].

We reviewed 680 cases of colorectal neoplasms with an incidence of 18 synchronous multiple carcinomas (2.7%). We describe the predominance in females (11/7), the late age of presentation (maximal incidence between 60 and 80 years) and the main symptoms of these patients. We remark the diagnostic difficulty of these tumors, despite all the methods used; the diagnosis of the second mass was intraoperative in 50% of the cases in our series. As treatment, we suggest partial colectomy, except when there is massive colonic affectation, in which we practice a total colectomy. The prognosis in these patients is similar to that of those who have a single carcinoma. We must carry out a rigorous follow-up of these patients to make an early diagnosis of any new metachronous tumors.