Contribution of the appendix to ulcerative colitis by supplying pathogenic immunoglobulin G-producing cells

Figure 1 Appendiceal inflammation as skip lesions in ulcerative colitis. A: The left part shows a macroscopic image of a surgical specimen from a patient with active ulcerative colitis who underwent total proctocolectomy (a1: Rectum, a2: Ascending colon, and a3: Appendix). The middle part presents endoscopic findings of the appendiceal orifice in ulcerative colitis. The right part displays a macroscopic image of the appendiceal orifice. The black arrows indicate appendiceal orifice inflammation. The stained sections in a1, a2, and a3 correspond to b1, b2, and b3, respectively; B: Hematoxylin and eosin staining of the rectum (b1), bar = 100 μm; ascending colon (b2), bar = 100 μm; appendix (b3), bars = 500 μm (left), and 50 μm [right (enlarged view of the black square in the left panel)].