Synchronous colorectal cancer.

Synchronous carcinomas of the colon and rectum are of considerable clinical significance because of their frequency, the number of extra tumours missed and the difficulty of preoperative diagnosis. A retrospective evaluation of 283 patients with primary colorectal adenocarcinomas was performed. There were 6 patients with 12 synchronous adenocarcinomas (2.12%). Colonoscopy and double-contrast barium enema revealed the synchronous cancer in 66.6% of the cases. In two cases the second cancer was found intraoperatively. In one patient an urgent laparotomy was performed because of acute abdomen caused by perforation of the ascending colon. Typical colectomies, depending upon the segment of the location of the lesion, were performed. Second cancers had a significantly more favourable stage than index colorectal adenocarcinomas. The index and the secondary cancers of synchronous colorectal adenocarcinomas showed a better histologic grade (well differentiated type) than the single cancers. Full clinical and radiological investigation is essential, before any operation is undertaken for colorectal cancer.