The histologic diagnosis of dysplasia, dysplasia-associated lesion or mass, and adenoma: a pathologist's perspective

Patients with ulcerative colitis are at an increased risk of developing dysplasia and carcinoma. The histologic recognition of dysplasia arising in this setting, particularly when patients have active colitis, can be challenging. However, even if it is clear that the patient has dysplasia, further challenges include the distinction of low-grade dysplasia from high-grade dysplasia and the distinction of an inflammatory bowel disease-related dysplastic lesion from a sporadic adenoma. This review article will summarize some of these issues from the gastrointestinal pathologist's perspective.