Condyloma acuminatum of the anal canal, treated with endoscopic submucosal dissection

Figure 1 Clinical evaluation of the case of a 28-year-old man who presented with hematochezia. A: Colonoscopy revealing 10-mm long, whitish condyles extending from the anal canal, with little normal intestinal membrane remaining in the proximal-to-distal site; B: The lesion is almost circumferentially located in the lower rectum, as observed using narrow band imaging (NBI); C: NBI magnification shows dilated red vessels on the surface of the lesion in the anal canal that are indicated as brownish capillaries with hairpin shapes or coil forms; D: Colonic biopsy specimens reveal acanthotic squamous epithelium with hyperpapillomatosis. The epithelial cells show koilocytosis, single cell keratinization, and mild-to-moderate dysplasia of the squamous epithelium. We highly suspected condyloma acuminatum related to human papilloma virus infection; E: Endoscopic submucosal dissection of the lesion all around the anal canal; F: Dissected specimen, 40 mm × 40 mm in diameter. White warts surround almost the entire anal canal (arrow).