This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET 2019, Subject name: Surgery
Histological difference between ulcerative colitis and Crohn's disease is presence of:- 
Select and explain. 
A. Crypt abscess, B. Diffuse distribution of pseudopolyps, C. Mucosal edema, D. Lymphoid aggregates in the mucosa
A: Crypt abscess
Answer: A: Crypt abscess 
Explanation: Among the given options Diffuse distribution of pseudo polyps- occurs in Ulcerative colitis > Crohn's Mucosal edema - occurs in both (UC&CD) Lymphoid aggregates - occurs in both Crypt abscesses - Most characteristic lesion of UC Crypt abscess: Collection of neutrophils fill and expand the lumina of individual crypts of Lieberkuhn Crypt abscesses are not specific for UC and can be seen in Crohn's disease . Crohn's Disease Clinical Features - MC symptom is intermittent and colicky abdominal pain, most commonly noted in the lower abdomen. Diarrhea is the next most frequent symptom and is present, at least intermittently, in about 85% of patients.. Main intestinal complications of Crohn's disease include obstruction and perforation. Fistulas occur between the sites of perforation and adjacent organs, usually at the site of a previous laparotomy. In Crohn's disease, ileum is the MC site of fistula (enterocutaneous and enterovesical), MC site of perforation and MC site of carcinoma.