Distribution and prevalence of colorectal hyperplastic polyps using magnifying pan-mucosal chromoendoscopy and its...

Patients with multiple (hyperplastic polyposis) or large hyperplastic polyps (HPs) predominantly in the right-sided colon, have been reported to have an increased risk of colorectal cancer (CRC). This prospective study was conducted to clarify the distribution of various sized HPs using magnifying pan-mucosal chromoendoscopy and its relationship with synchronous CRC.

Patients eligible for this study had an initial total colonoscopy. Indigo carmine dye was sprayed throughout the whole colon and rectum, and diagnoses were made using magnifying colonoscopy.

A total of 263 patients were enrolled, and a total of 3060 HPs were observed in 226 (86%) patients. The prevalence of patients with intermediate size (> or = 6 mm) HPs was 8.7% (n = 23) and that of patients with large HPs (> or = 10 mm) was 0.8% (n = 2). Of 3060 HPs, the numbers of diminutive (< 6 mm), intermediate size and large HPs were 3020, 38 and two, respectively, and 5.0%, 42.1% and 100% of these were located in the right-sided colon, respectively. Synchronous CRC was observed in 64 (24%) of 263 patients. Compared to patients without HPs, patients with intermediate size HPs showed a significant increase in odds ratio (OR) for synchronous CRC (OR = 4.9: 95% CI [1.3-18.2]), but there was no significant association between synchronous CRC and patients with diminutive or large HPs.

Compared to diminutive HPs, intermediate size and large HPs were predominantly located in the right-side colon. Moreover, intermediate size HPs were significantly correlated with synchronous CRC.