Histologic mimics of inflammatory bowel disease

This review summarizes a variety of clinical and histologic mimics of idiopathic inflammatory bowel disease. All the entities that are included demonstrate one or more histologic features typical of idiopathic inflammatory bowel disease that may lead to potential diagnostic confusion and misinterpretation by the pathologist. The elements of the clinical history, laboratory test results, and endoscopic findings that are helpful to the surgical pathologist in considering a diagnosis other than idiopathic inflammatory bowel disease are emphasized. On occasion, a poor response to standard treatment for idiopathic inflammatory bowel disease is the clue that prompts reconsideration of the initial diagnosis. Subtle histologic features, special stains, or other diagnostic methodologies that can aid in proper diagnosis are also discussed.