PMC4448049_01
a A white, flat, elevated lesion, 15 mm in size, was identified from the rectum to the dentate line of the anal canal on internal hemorrhoids. b NBI showed irregular vascular patterns (dilatation, tortuous running, caliber changes, and different shapes). c A chromoendoscopy with indigo-carmine dye showed the edge of the lesion clearly and revealed a lobulated, flat, elevated lesion. d The lesion was identified by chromoendoscopy with iodine staining as the stained area, with some unstained parts observed. e The ulcer after en bloc resection. f The resected specimen. g The tumor was composed of well-differentiated SCC in situ. The vertical and horizontal cut ends of the tumor were both negative. In the superficial layer, koilocytosis was recognized. h-j An immunohistochemical evaluation showed strong expressions of p53 (h), Ki-67 (i), and p16 (j), indicating that the patient was infected with HPV.
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F1
A white, flat, elevated lesion, 15 mm in size, was identified from the rectum to the dentate line of the anal canal on internal hemorrhoids (fig. 1a). Magnifying endoscopy with narrow-band imaging (NBI) showed irregular vascular patterns (dilatation, tortuous running, caliber changes, and different shapes) (fig. 1b). A chromoendoscopy with indigo-carmine dye showed the edge of the lesion clearly; it revealed a lobulated, flat, and elevated lesion (fig. 1c). Next, the lesion was further confirmed using iodine staining (fig. 1d). SCC of the anal canal (carcinoma in situ). Subsequently, ESD was performed en bloc without any complications (fig. 1e, f). In the superficial layer, koilocytosis, a change of cytoplasms with vacuoles, was recognized (fig. 1g). An immunohistochemical evaluation showed strong expressions of p53, Ki-67, and p16, indicating that the patient was likely infected with the human papillomavirus (HPV) (fig. 1h-j).
PMC4448049_02
a A white, papillary, flat, elevated lesion, 25 mm in size, was identified from the dentate line to the anal canal. b NBI showed irregular vascular patterns (dilatation, tortuous running, caliber changes, and different shapes) at the elevated lesion. c A chromoendoscopy with indigo-carmine dye showed the edge of the lesion clearly and revealed a lobulated, elevated lesion. In addition, this lesion was clearly visible inside the dentate line. d The lesion was identified by chromoendoscopy with iodine staining as the stained area. e The rectal area after en bloc resection showing the entire circumferential ulcer. f Macroscopic findings from the resected specimen. g The tumor was composed of SCC in situ. The vertical and horizontal cut ends of the tumor were both negative. The histopathological diagnosis was of SCC in situ without vessel invasion. h-j An immunohistochemical evaluation showed strong expressions of p53 (h), Ki-67 (i), and p16 (j).
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F2
She underwent a colonoscopy, and a white, papillary, flat, elevated lesion, 25 mm in size, was identified from the dentate line to the anal canal (fig. 2a). A magnifying endoscopy with NBI showed irregular vascular patterns (dilatation, tortuous running, caliber changes, and different shapes) (fig. 2b). In addition, this lesion was clearly visible inside the dentate line (fig. 2c) and easily identified by chromoendoscopy with iodine staining (fig. 2d). The lesion was resected en bloc with the entire circumference of the rectum lumen (fig. 2e, f); it was found to be composed of SCC. In the superficial layer, koilocytosis was observed (fig. 2g). An immunohistochemical evaluation showed strong expressions of p53, Ki-67, and p16 (fig. 2h-j).