Colon   4.1  Signet-ring cell change vs. Signet-ring cell carcinoma   4.2  Atypical stromal cells in polyps and ulcers vs. Sarcoma   4.3  Crohn colitis vs. Diverticular-associated colitis   4.4  Squeeze artifact vs. Ischemic colitis   4.5  Normal macrophages and…

Stomach   2.1  Crush artifact vs. Signet-ring cell carcinoma   2.2  Signet-ring cell change vs. Signet-ring cell carcinoma   2.3  Xanthoma vs. Signet-ring cell carcinoma   2.4  Iron pill gastritis vs. Dysplasia   2.5  Reactive changes of stress gastritis vs….

Small Intestine   3.1  Crushed Brunner glands vs. Whipple disease   3.2  Crushed Brunner glands vs. Mesenchymal lesions in small bowel mucosa   3.3  Chronic duodenitis vs. Intracytoplasmic lipid   3.4  Chronic duodenitis vs. Abetalipoproteinemia   3.5  Atypical stromal cells…

Esophagus   1.1  Iron pill esophagitis vs. Squamous dysplasia   1.2  Reactive multinucleated squamous cells vs. Herpes virus cytopathic effect   1.3  Reactive stromal changes vs. Cytomegalovirus esophagitis   1.4  Goblet cells in Barrett esophagus vs. Multilayered epithelium…

Appendix   5.1  Granulomatous appendicitis vs. Crohn disease of the appendix   5.2  Interval appendix vs. Crohn disease of the appendix   5.3  Infectious appendicitis with granulomas vs. Crohn disease of the appendix   5.4  Low-grade appendiceal mucinous…

Anal Canal   6.1  Papillary endothelial hyperplasia in hemorrhoidal vessels vs. Angiosarcoma   6.2  Condyloma lata vs. Squamous cell carcinoma   6.3  Condyloma vs. Fibroepithelial polyp (anal tag)   6.4  Stromal changes in fibroepithelial polyp vs. Sarcoma   6.5  Reactive…