Synchronous and early metachronous carcinomas of the colon and rectum.

Over a five-year period, 201 patients were admitted to Hairmyres Hospital with a colorectal carcinoma. Eight (4%) patients had a synchronous carcinoma and one (0.5%) patient had an early metachronous carcinoma. Synchronous neoplasms were detected in only one (12.5%) patient pre-operatively, six per-operatively, and one was found in a panproctocolectomy specimen at pathological examination. Four (50%) synchronous neoplasms occurred in relative close proximity to the index neoplasm. We suggest that some 'missed' synchronous carcinomas may manifest themselves as apparent anastomotic recurrences rather than early metachronous lesions. We conclude that greater effort is required to detect synchronous tumors peri-operatively and endoscopic colonic follow-up is necessary to detect 'missed' synchronous lesions and recurrences.