Correlation of pit pattern by magnifying colonoscopy with histologic features and COX-2 expression in colonic polyps

Chung, Jun Won; Chang, Hye Sook; Myung, Seung Jae; Kim, Tae Hun; Lee, Young Mi; Byeon, Jeong Sik; Yang, Suk Kyun; Kim, Jin Ho

Abstract

BACKGROUND/AIMS: Magnifying colonoscopy (MC) was introduced for prediction of pathologic findings. However, cyclooxgenase-2 (COX-2) expression in colonic polyps according to pit pattern has not been reported before. The aims of this study were to evaluate the usefulness of MC for differentiating polyps and to analyze COX-2 mRNA expression in colon polyps according to pit patterns.
METHODS
We studied 36 patients (M:F=26:10; median age 55 years) who received endoscopic polypectomy at Asan Medical Center. The pit patterns were classified into six types (type I, II, IIIL, IIIS, IV, and V). The expression of COX-2 mRNA was determined by reverse transcription-polymerase chain reaction.
RESULTS
Among 41 polyps from 36 patients, 38 polyps were diagnosed as benign colon polyps, and 3 polyps were diagnosed as early colon cancer. In assessing the histologic findings according to pit patterns, non-adenomatous polyps were detected in 50% of type I and II patterns, and pre-malignant polyps were detected in 94.5% of type IIIL, IIIS, IV, and V patterns. COX-2 mRNA expression rate increased in parallel with histologic grade (p=0.022). However, this was not correlated with pit pattern.
CONCLUSIONS
MC pit patterns provide detailed gross morphologic features. COX-2 mRNA expression rate, while related to histologic progression, is not related directly to pit pattern, but further study is needed.