Inflammatory bowel disease (ulcerative colitis and Crohn's disease): diagnostic criteria and differential diagnosis.Drugs Today (Barc). 1998 Nov;34(11):935-42.

Chronic inflammatory bowel diseases (i.e., ulcerative colitis and Crohn's disease) are syndromes in which standardized criteria are necessary in the diagnostic process. The present review is based on the diagnostic criteria used at our institution. We base the diagnosis of ulcerative colitis and Crohn's disease on combined information from the patient history, and radiological, endoscopic and histological findings after exclusion of neoplastic and infectious disease. The patient history must include precise information on the nature and duration of symptoms as well as the presence of relevant influential factors such as travel activity, drug intake and sexual habits. In immunocompromised patients extensive microbiological investigations are required to exclude infection. Typical radiological and colonoscopic findings in ulcerative colitis are mucosal inflammatory changes extending circumferentially and continuously from the rectum and proximally in the colon. In contrast, Crohn's disease is most frequently located in the small bowel and in case of colonic involvement, the rectum is often spared. The best predictors of Crohn's disease are discontinuous lesions, cobblestones and apthous ulceration. Histological changes such as abnormal mucosal architecture and lamina propria cellularity, neutrophil polymorph infiltration and epithelial cell abnormality are useful and reproducible features in the evaluation of colorectal biopsy specimens. The inflammatory bowel diseases, ulcerative colitis and Crohn's disease, continue to be etiological and diagnostic challenges. Increased use of standardized criteria and diagnostic algorithms are essential instruments to improve the overall quality of the management of patients with these diseases.

Granulomatous ulcerative colitis: a re-appraisal of the mucosal granuloma in the distinction of Crohn's disease from ulcerative colitis.Histopathology. 2002 Jul;41(1):50-5.

AIMS: To determine whether the presence and location of giant cells or granulomas in relation to crypts distinguishes between ulcerative colitis and Crohn's disease. METHODS AND RESULTS: Twenty-nine large bowel mucosal biopsy specimens showing giant cells and/or granulomas in a background more typical of ulcerative colitis than Crohn's disease were collected between 1986 and 1996. Each was subject to detailed independent analysis by three histopathologists. Follow-up of the cases was by examination of all previous and subsequent gastrointestinal surgical or biopsy material and by scrutiny of the clinical notes by a gastroenterologist. On the basis of the accumulated histological data 10 of these 29 cases were accorded the diagnosis of ulcerative colitis. In nine of these 10 cases the clinical diagnosis, where known, was in keeping with this and all nine contained only crypt-associated giant cells and/or granulomas. The tenth case contained a solitary free-standing granuloma and clinically the patient had perianal disease, suggesting that the true diagnosis was Crohn's disease. CONCLUSIONS: Isolated giant cells and well-defined epithelioid granulomas distant from crypts do not, as a rule, occur in ulcerative colitis, and hence their presence in a colonoscopic biopsy showing features of chronic inflammatory bowel disease is a strong pointer towards the diagnosis of Crohn's disease. Crypt-associated giant cells and granulomas can occur in ulcerative colitis and in themselves are unreliable features for the discrimination between Crohn's disease and ulcerative colitis.