1. Case 1

6. Diagnosis : A. Colon, transverse, mid, endoscopic mucosal resection: Tubular adenoma with low grade dysplasia with 1) Size: 1.2 x 1.0 x 0.7 cm 2) Negative resection margin (Safety margin: 0.2 cm) B. Colon, sigmoid, colonoscopic biopsy: Tubular adenoma with low grade dysplasia C. Rectum, 10cm from anal verge, polypectomy: Tubular adenoma with low grade dysplasia D. Rectum, 7cm from anal verge, polypectomy: Tubular adenoma with low grade dysplasia

7. Case 2

10. Diagnosis : A. Colon, sigmoid, colonoscopic biopsy: Chronic inflammation B. Rectum, colonoscopic biopsy: Chronic inflammation Diagnosis : Stomach, antrum, endoscopic biopsy: Chronic gastritis (no granuloma) Diagnosis : Duodenum, second portion, endoscopic biopsy: Chronic inflammation (no granuloma)

16. Diagnosis : Colon, sigmoid, sigmoidectomy: Crohn's disease, consistent with Lymph node, regional, sigmoidectomy: Reactive change (x3)

17. Case 3

20. Diagnosis : A. Colon, descending, polypectomy: Tubular adenoma with low grade dysplasia B. Colon, sigmoid, colonoscopic biopsy: Tubular adenoma with low grade dysplasia C. Colon, sigmoid, colonoscopic biopsy: Chronic inflammation

25. Diagnosis : Sigmoid colon, sigmoidectomy: Fibrous adhesion with chronic inflammation

26. Case 4

29. CD20

30. CD3

31. Bcl-2

32. Bcl-6

33. MUM-1

34. Ki-67

35. Diagnosis : Colon, ascending, proximal, colonoscopic biopsy: Diffuse large B-cell lymphoma

36. Case 5

38. Colon, sigmoid, colonoscopic biopsy: Dysplasia, low grade (History of ulcerative colitis)

41. A. Colon, 75cm from anal verge, colonoscopic biopsy: Chronic inflammation B. Colon, 72cm from anal verge, colonoscopic biopsy: Ulcer with acute and chronic inflammation C. Colon, 38cm from anal verge, colonoscopic biopsy: Chronic inflammation D. Colon, 30cm from anal verge, colonoscopic biopsy: Chronic inflammation