This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': "Skip granulomatous lesions are seen in - \nSelect and explain. \nA. Ulcerative colitis, B. Crohn's disease, C. Whipple's disease, D. Reiter's disease", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Features of CD \n\nIleum is involved most commonly; therefore, CD is also known as terminal ileitis.\nIn the affected segment, mesentric fat wraps around the bowel surface → creeping fat.\nThe intestinal wall is rubbery and thick, as a consequence of edema, inflammation, fibrosis, and hypertrophy of the muscularis propria → lumen is almost always narrowed string sign on barium meal.\nA classic feature of CD is the sharp demarcation of diseased bowel segments from adjacent uninvolved bowel. When multiple bowel segments are involved, the intervening bowel is normal → skip lesions.\nThere are serpentine linear ulcer along the axis of bowel.\nAs the intervening mucosa tends to be relatively spared, the mucosa acquires a coarsely textured → Cobblestone appearance.\nNarrow fissures develop between the folds of the mucosa.\nFissures can penetrate deeply through the bowel wall and leading to bowel adhesions and serositis.\nFurther extension of fissures leads to fistula or sinus tract formation.\nThere is transmural inflammation affecting all layers of bowel wall.\nSarcoid like noncaseating granulomas may be present in all tissue layers.\nNeutrophilic infiltration into the crypts results in formation of crypt abscess.\nFibrosis of the submucosa, muscularis propria, and mucosa enentually leads to stricture fromation.\nThere is an increased incidece of cancer of GIT in patints with long- standing CD, but the risk of cancer in CD is considerably less then in patients with chronic UC.\nScreening test is presence of anti-Saccharomyces cerevisae antibody (ASCA). Antibody formation is common against cell wall of yeast, Saccharomyces cerevisae in patients of CD.\nTo confirm the diagnosis endoscopy is done so that direct visualization of the lesion can be done and even a biopsy can be done if needed.', 'role': 'assistant'}]