Small nonpolypoid colorectal carcinoma.

The objective of this study was to characterize and assess the presence and frequency of small nonpolypoid colorectal adenocarcinomas among patients with colorectal cancer referred for surgery. The medical, endoscopic, and surgical reports and the histopathologic slides of all patients operated on for colorectal cancer were retrospectively reviewed. Small nonpolypoid colorectal cancer (SNPCC) was defined as a malignant, nonpolypoid lesion smaller than 15 mm. SNPCC was classified according to the Japanese macroscopic classification of colorectal carcinoma. The frequency of SNPCC among patients referred for operation was 1.8%. Most of these patients were asymptomatic and were diagnosed by the same endoscopist using a high-resolution video-endoscope without the assistance of enhancement techniques. These lesions had a mean size of 10.8 mm, were mainly of the flat or flat elevated type, and were located in the distal colon. Among patients with colorectal cancer referred for surgery, 1.8% had SNPCC. These lesions can be detected using high-resolution video-endoscopy equipment without the need for enhancement techniques, as reported in Japanese series. Increased awareness of the existence of such SNPCC lesions may help the average endoscopist detect such lesions. As SNPCC represents colorectal cancer, all the cases in our series were treated by typical oncologic surgical resection.