Severe dysplastic lesions in the colon - how aggressive should we be?

INTRODUCTION: Biopsies of colonic lesions are often reported as showing dysplasia, though in reality some lesions may harbour invasive malignancy. AIM: To assess the risk of underlying invasive malignancy in sessile polyps where biopsies had shown severe dysplasia and also to attempt to define a management strategy in such patients. METHODS: Between 1997 and 2001, 30 patients were diagnosed as having severe dysplasia using Morson's criteria in colonic lesions not amenable for endoscopic polypectomy. Severely dysplastic lesions were completely excised by appropriate surgical measures. RESULTS: Out of 30 patients, 15 had invasive cancers. Surgical intervention involved anterior resections, endoanal excisions, sigmoid colectomies, or abdomino-perineal excisions as deemed appropriate. The lesions ranged in size from 0.5 cm to 13 cm (mean 3.4 cm). There were nine T1 lesions (one of which was T1N1) and two each of T2, T3, T4 lesions (10 Dukes' A, 3 Dukes' B, 2 Dukes' C). Complete resection was confirmed histologically in all cases. One patient had a leak following endoanal excision, which required intervention. There was no mortality. DISCUSSION: This study demonstrates that endoscopic sampling can be misleading and severely dysplastic sessile lesions should be managed along the same principles as followed for invasive cancers, rather than adopting a 'wait and watch' policy with repeated endoscopies, biopsies or piece-meal polypectomies.