Dysplasia and early carcinoma in inflammatory bowel disease and colorectal adenomas.

The control of colorectal cancer is currently dependent on early detection, and its prevention requires the recognition and treatment of its precursor lesions. The adenoma has been established as the precursor of colorectal carcinoma in the general population. Among patients with inflammatory bowel disease (IBD), dysplasia is associated with, and precedes, invasive carcinoma. In this section criteria are described for the histological detection of preinvasive and early invasive neoplasia in the large intestine of patients with and without IBD. The therapeutic implications of these diagnoses are stressed. A brief review of subcellular changes, including genetic alterations, in colorectal neoplasia is included.