Study on the relationship between the pit pattern and histology of colorectal polyps / 中华消化内镜杂志

ABSTRACT

Objective The aim of this study was to reveal the clinical features of colorectal polyps by investigating its endoscopic features using a magnifying videoscope. Methods One hundred and five colorectal polyps presented in colonoscopy were included in this study. A magnifying videoscope with a zoom ranging from ? 1 to ? 100 magnification combined with indigocarmine dye was employed to observe the pit pattern of colorectal polyps. Pit pattern was analyzed according to Kudo' s modified classification as follows; (1) type Ⅰ ; round pit; (2) type Ⅱ; asteroid; (3) type Ⅳs; tubular or round pit, which is smaller than the normal pit (type Ⅰ ) ; (4) type ⅢL tubular or round pit, which is larger than the normal pit (type Ⅰ ) ; (5 ) type Ⅳ dendritic or gyrus - like pit; ( 6 ) type Ⅴ irregular or amorphous pit; and ( 7 ) mixed type. Types Ⅰ and Ⅱ represented the pit pattern of nonneoplastic polyps and types Ⅲ L , Ⅲs, Ⅳ , Ⅴ , and mixed type represented the adenomatous polyps represented neoplastic polyps. Results In all samples of polyps, 17 were of the pedunculated type, 40 subpedunculated type and 48 sessile type. Among the 17 pe-dunculated type, 12 were type Ⅰ ,Ⅱ pit pattern. In those subpedunculated types, type Ⅰ , Ⅱ pit pattern were found in 15. 0% (6/40) , type ⅢL , Ⅲs , Ⅳ, and Ⅴ were detected in 85. 0% (34/40) . Type Ⅰ ,Ⅱ pit pattern were found in 41. 7% (20/48), type Ⅰ,ⅢL, ⅢS, Ⅳ, and V were in 58.3% (28/48) in sessile type. Of all polyps 88 (83. 8% ) were situated between the splenic flexure and rectum , but'no correlation was found between pit pattern and location of polyps. The incidences of neoplastic changes in the lesions with pit pattern Ⅰ,Ⅱ ,ⅢL, Ⅲs,Ⅳ, Ⅴ , and mixed type were 0% , 11. 8% , 77. 3% , 75. 0% , 100. 0% , 100. 0% , and 70. 0% , respectively. The diagnostic sensitivity of neoplastic and nonneoplastic polyps were 96. 7% and 80. 0% , and specificity were 86. 6% and 94. 7% . The overall diagnostic accuracy in differentiating neoplastic from nonneoplastic polyps was 89. 5% . Conclusions The pit pattern analysis of colorectal polyps by magnifying colonoscopy combined with indigocarmine staining is a useful and objective tool fur differentiating nonneoplastic lesions from adenomas or invasive carcinoma of the large bowel. There-fore it may be possible to determine, at the lime of colonoscopy, which lesions require treatment or not, and which one should be removed by endoacopy, or by surgery.