Abstract :
Objective: To find the prevalence of significant colorectal polyps in average-risk Thais, to assess morphology
and location distribution of these polyps within the colon, and to correlate them with pathological results
after endoscopic removal.
Materials and Methods: Retrospective review of CT colonography (CTC) in average-risk people
whose ages were ≥ 50 years old was performed from February 2006 to May 2007. There were 690 people of which
253 (36.7%) were male and 437 (63.3%) were female. Age range was 50-85 years with mean and median age of 62,
and 60 years, consecutively. The presence, location, size and morphology of colorectal polyps were assessed in six
colonic segments. People whose colonoscopy were performed, histology of all removed polyps was acquired
through pathology report and compared with CTC findings.
Results: Of 690 people, 671 had complete data for review. Significant polyps of ≥ 6 mm were found in
66 people (9.8%). Of these 66 polyps, 53 (80.3%) were sessile, 12 (18.2%) were pedunculated, and 1 (1.5%) was
plaque, flat lesion. Of these 66 polyps, 47 (71.2%) were found in the distal colon (transverse colon to rectum) and
19 (28.9%) in proximal colon (cecum and ascending colon). Large-size polyps of ≥ 10 mm, considered to be
advanced polyp, were found in 13/671 people (1.9%). Of these 13 people, 11 proceeded for colonoscopy and 10/11
(90.9%) polyps were adenomas and 1/11 (9.1%) was hyperplastic polyp. Medium-sized polyps of ≥ 5-9 mm were
found in 53/671 people (7.9%). Of these 53 people, 16 proceeded for colonoscopy of which one polyp was not
found. Of the remaining 15 medium-sized polyps, 10 (66.7%) were adenomas, 4 (26.7%) were hyperplastic polyps
and 1 (6.6%) was inflammatory polyp.
Conclusion: Based upon CTC, the prevalence of significant colorectal polyps of ≥ 6 mm in the average-
risk Thais was approximately 10% with 2% to be advanced polyps of ≥ 10 mm. Majority of polyps were found
at distal colon and majority were of sessile morphology. If polyps were of medium size (6-9 mm), the chance of
being neoplastic adenomas was about 67%. If polyps were of large size (≥ 10 mm), the chance of being neoplastic
adenomas was about 91%. |
file/Thai-Journal-of-gastroenterology-vol-11-no-2-1234356.pdf