Polypoid dysplasia in inflammatory bowel disease: differential diagnosis and further diagnostic and therapeutic approaches

Polypoid dysplasia in inflammatory bowel disease (IBD) is categorized as DALM (dysplasia associated lesion or mass) or ALM (adenoma-like mass). DALMs are etiologically related to the underlying inflammatory disease, have a high risk of cancer and remain an indication for colectomy. Sporadic adenomas occur coincidentally according to the adenoma-carcinoma sequence. They are adequately treated by polypectomy. More recently, a special group of lesions has been termed as "adenoma-like DALM" which shows a morphological overlap with sporadic adenomas in spite of arising against the background of chronic IBD. Adenoma-like DALMs may possess a lower risk of malignancy in contrast to non-adenoma-like DALMs. They may be treated adequately by polypectomy and continued monitoring if the lesion has been excised completely and there is no evidence of flat dysplasia elsewhere in the colon.