Total colonic polyp diameter: a marker for the risk of malignancy?

BACKGROUND/AIMS: The correlation of the risk of malignancy with the sum of the diameters of small colonic polyps is unknown, and data regarding this topic are lacking. In this study, the relationship between the sum of the diameters of the total number of colonic polyps and poor histopathologic characteristics was examined. METHODS: A total of 920 neoplastic colon polyps were evaluated in 480 patients. The "total polyp diameter" (i.e. the sum of all polyp diameters identified during colonoscopy), which was calculated in each patient by adding the diameter of each polyp to a sum, was categorized as "small" (<10mm in diameter) or "large" (> or =10mm in diameter). The polyps were further categorized by histopathologic component as "unfavorable" or "favorable" and were divided into 2 groups: group 1 (those identified as carci noma, carcinoma in situ, villous adenoma, and tubulovillous adenoma with a villous component of more than 25%) and group 2 (mixed adenomatous polyps with various degrees of hyperplastic or inflammatory components and adenomas with a tubular component of more than 75%). RESULTS: Large polyps that had a total diameter greater than or equal to 10mm tended to have poor histopathologic characteristics (p<0.05). Polyps generally tended to localize in the left portion of the colon, and malignant polyps or those at risk for malignancy in particular tended to localize in the left colon (p<0.05). CONCLUSIONS: Polypectomy is recommended for patients in whom the sum of the diameter of all colonic polyps exceeds 10mm.

Malignancy risk of small polyps and related factors.

The aim of this study was to determine the risk of polyps <6 and between 6 and 10 mm in terms of progression to malignancy and to evaluate the influence of age, gender, and colonic localization on malignancy development. Thirteen hundred sixty-nine polyps <10 mm identified in 680 patients were retrospectively evaluated. Sixty-seven and two-tenths percent of polyps <10 mm were of a neoplastic nature. The incidence of neoplasia was higher in left-sided and small polyps than diminutive polyps. In patients older than 60 years, small polyps showed a higher rate of high-risk histology than diminutive polyps,while the same relationship did not exist in other age groups. In male patients over 60 years of age, the rate of high-risk histology was higher in small polyps than in diminutive polyps.