The nature of the white opaque substance within colorectal neoplastic epithelium as visualized by magnifying endoscopy with narrow-band imaging

Abstract

We previously reported our discovery of presence of an intraepithelial white opaque substance (WOS) that is opaque to light during magnifying endoscopic observation of gastric epithelial tumors (adenomas and carcinomas) and chronically inflamed gastric mucosa (intestinal metaplasia) [1-3]. In subsequent histopathologic analyses, we found that this WOS comprised minute lipid droplets (LDs) that were densely accumulated beneath the mucosal epithelium or within the epithelium of gastric tumors and intestinal meta-plasia [4]. These LDs appear as a white substance due to their intense backscattering of light [4]. Furthermore, magnifying endoscopy (ME) of large intestinal epithelial neoplasms (adenomas and carcinomas) revealed the same intraepithelial WOS as that seen in the gastric tumors [5, 6]. However, whether the WOS discovered in large intestinal epithelial neoplasms comprises the same accumulation of LDs detected in the gastric tumors remains unclear. Therefore, the goal of the current study was to determine whether the WOS visualized by ME with narrow-band imaging (NBI) on the surface of large intestinal epithelial neoplasms was in fact minute LDs that had accumulated within the epithelium. Patients and methods ! Patients This study was approved by the Institutional Review Board of the University of Fukuoka and was registered with UMIN (000011220). All participating patients were supplied with an explanation of the study and provided their written, informed consent. The inclusion criteria were: (1) colorectal epithe-lial tumors (adenomas and carcinomas) planned for endoscopic mucosal resection and endoscopic submucosal dissection (EMR and ESD) at the Department of Endoscopy of the Fukuoka University Chikushi Hospital; (2) Eastern Cooperative Oncology Group (ECOG)-performance status either 0 or 1 [7]; (3) age 20 years or over at the time of registration ; and (4) written, informed consent. Imamura Kentaro et al. Visualization of white opaque substance within colorectal neoplastic epithelium … Endoscopy International Open 2016; 04: E1151-E1157 Background and study aims: We previously reported our discovery of a white opaque substance (WOS) that is opaque to endoscopic light inside the epithelium while using magnifying endos-copy (ME) to examine gastric epithelial neoplasia. Histopathologic analysis revealed that the WOS comprises minute lipid droplets (LDs) accumulated within the neoplastic epithelium. In addition, the WOS was found in colorectal epithe…