case_images: PMC4119926_01
case_images: Macroscopic appearance.
case_images: CRIPA2014-979674.001.jpg
case_images: PMC4119926_01_CRIPA2014-979674.001.jpg
case_images: fig1
case_images: Macroscopically, after formalin fixation, the resected specimen showed a clearly demarcated ulcer, measuring 28 x 20 mm maximum dimensions, in the ascending colon (Figure 1).
case_images: (a) SSL in the root of the appendix. (b) SSL is regionally observed in the right half of the epithelium, while nondysplastic epithelium can be observed in the left half. SSL shows the loss of hMLH-1 expression; however, a weak to moderate reactivity is preserved in the deep part of the crypts. A hMLH-1 positive control was evaluated on nondysplastic epithelium. The scale bars indicate 250 micrometers.
case_images: CRIPA2014-979674.002.jpg
case_images: PMC4119926_01_CRIPA2014-979674.002.jpg
case_images: fig2
case_images: The noticeable finding of this present case was the SSL which included serrated structure, crypt dilation, and horizontally arranged basal crypts, in the root of the appendix (Figure 2(a)). Concerning IHC features, the expression of hMLH-1, which is a DNA mismatch-repair protein, was absent in the SSL, although its expression was inclined to be preserved in the deeper part of crypt (Figure 2(b)).
case_images: (a) The area of gradual transition between the mucinous adenocarcinoma and SSL in the peripheral side of the appendix, but the serrated structure is not outstanding. (b) The component of mucinous adenocarcinoma without serrated structure. The scale bars indicate 500 micrometers.
case_images: CRIPA2014-979674.003.jpg
case_images: PMC4119926_01_CRIPA2014-979674.003.jpg
case_images: fig3
case_images: Moreover, the SSL combined with dysplastic change extended to the adjacent mucinous adenocarcinoma with an area of gradual transition (Figure 3); this SSL was pathologically regarded as a potential precursor lesion of the adjacent mucinous adenocarcinoma.