Abstract
Diminutive colonic polyps (less than 5mm in diameter) were removed endoscopically by conventional biopsy forceps or diathermy-biopsy (hot biopsy) amounting to 1, 010 specimens from April 1982 to July 1984. There were several kinds of histology recongnized among them : 660 tubular adenomas, 2 tubulo-villous adenomas, 4 focal carcinomas and one carcinoid tumor. Non-nepolasias consisted of 231 hyperplastic polyps, 63 normal, 19 lymphoid nodules, 11 hamartomas (9 Peutz-Jeghers type polyps and 2 juvenile polyps), 10 inflammatory polyps, 6 xanthomas, 2 lipomas and one leiomyoma. Neplaosias were seen in 667 out of 1, 010 (66.0%). Tubular and tubulovillous adenomas showed mild dysplasia in 55.2%, moderate dysplasia in 10.3% and severe dysplasia (focal carcinoma) in 0.4%. Malignant polyps might be found in these smaller size growths. Diminutive neoplastic polyps are evenly distributed in all sites of the colon and rectum: 10.2% in the rectum, 28.6% in the sigmoid colon, 14.1% in the descending colon, 21.7% in the transverse colon and 25.3% in the right colon. There is a large discrepancy in the distribution between diminutive neoplastic polyps and the large size polyps over 6mm in diameter. For instance, the large polyps occurred in the sigmoid colon in 53.2% compared to only 28.6% of the dimutive ones. From an endoscopic point of view, some differences of the color of diminutive polyps were noticed. These colors were classified into 4 categories, (1) orange color, (2) similar to background mucosal color, (3) bluish color, (4) micellaneous (pale gray, reddish, white spotted, etc.). Neoplasias were highly correlated with the following colors : orange in 88.5%, similar to background in 72.8% and bluish in 69.6%. There was a low incidence of neoplasia in the miscellaneous group (4.9%). In conclusion, colonic diminutive polyps should not be ignored or overlooked clinically. The majority were neoplastic polyps including a few focal carcinomas. It is suggested that diminutive polyps should be removed endoscopically if possible.
