This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammatory bowel disease, Subject name: Surgery
Cobble stone appearance is seen in: 
Select and explain. 
A. Ulcerative colitis, B. Crohn's disease, C. Appendicitis, D. Carcinoma rectum
B: Crohn's disease
Answer: B: Crohn's disease 
Explanation: Crohn's Disease Earliest gross pathologic lesion is a superficial aphthous ulcer noted in the mucosa. Linear ulcers may coalesce to produce transverse sinuses with islands of normal mucosa in between (cobblestone appearance) Characteristic histologic lesions of Crohn's disease are noncaseating granulomas with Langerhan's giant cells.