Histological Assessment of Colorectal Adenomas by Size. Are Polyps Less than 10 mm in Size Clinically Important?

• Published in: The European journal of surgery Vol. 167; no. 10; pp. 777 - 781
• Main Author: J. Aldridge, Jay N. L. Simson, Andrew
• Format: Journal Article
• Language: English
• Published: Informa UK Ltd 01.10.2001
• ISSN: 1102-4151; 1741-9271
• DOI: 10.3109/11024150152707770

Objective: To define the relative risk of malignant transformation in colorectal adenomas less than 10 mm in diameter. Design: Prospective study. Setting: District general hospital, UK. Subjects and materials: 1228 polyps detected endoscopically in 445 patients over the 10-year period 1989-1999. Main outcome measures: Site, size, histological type and dysplastic grade of polyp. Results: 657 of the 1228 polyps were adenomas: 281 (43%) tubular, 339 (51%) tubulovillous and 37 (6%) villous. In the 357 adenomas less than 10 mm in diameter, 11 (3%) were severely dysplastic and 2 carcinomas were detected, though neither was less than 5 mm in size. The relative risk of malignancy or severe dysplasia in adenomas of 10 mm or more compared with those of less than 10 mm was 3.8 ( p < 0.0001). Conclusions: Although severe dysplasia and malignancy do occur in adenomas less than 10 mm in size, they are rare in lesions of less than 5 mm. We recommend routine destruction of all polyps 5 mm or more in size, though it is not essential to remove those of less than 5 mm if they are kept under surveillance.