Magnifying chromoendoscopic and endocytoscopic findings of juvenile polyps in the colon and rectum

A precise endoscopic diagnosis is necessary for endoscopic therapy for neoplastic and non-neoplastic lesions, including juvenile polyps (JPs). Therefore, the present study aimed to clarify the characteristic endoscopic findings of JPs. A total of 154 JPs were evaluated by magnifying chromoendoscopy, 20 of which were also assessed by endocytoscopy using an ultra-high magnification endoscope. Endoscopic images were evaluated in terms of gross appearance, color, pit pattern, surface inflammatory changes and vascularity of polyps. Endocytoscopic images were evaluated with regard to the morphology of glandular cavities, nuclei of glandular cells and interstitial features. Reddish surfaces (98.1%), surface erosion (92.2%), open pits (90.3%) and low pit density (90.3%) were observed in the majority of JPs by chromoendoscopy. In addition, dilated ductal openings surrounded by normal glandular cells (100%), greater distances between gland basal layers (100%) and interstitial infiltration by inflammatory cells (100%) were observed in all JPs examined by endocytoscopy. These findings indicate that there is a tetralogy of magnifying chromoendoscopic findings characteristic of JPs: Reddish surfaces, surface erosion, open pits and low pit density. There is also a triad of endocytoscopic findings characteristic of JPs, namely dilated ductal openings surrounded by normal glandular cells, greater distances between gland basal layers, and interstitial infiltration by inflammatory cells. The aforementioned magnifying chromoendoscopic and endocytoscopic characteristics of JPs may be useful factors for diagnosing JPs.