RESUMO
BACKGROUND AND AIM: At present, there is no recognized diagnostic criteria for gastric low-grade intraepithelial neoplasia (LGIN). The purpose of this study was to determine whether an "endoscopic acanthosis nigricans appearance (EANA)" could be a useful endoscopic marker for distinguishing LGIN lesions from peripheral non-neoplastic tissues. METHODS: A retrospective study was conducted on 638 cases of suspected superficial lesions with endoscopic images from white light endoscopy and magnifying endoscopy combined with narrow band imaging. According to the pathological results of accurate biopsies, those lesions were divided into three groups: a control group, an LGIN group, and an early gastric cancer (EGC) group. RESULTS: According to the presence of EANAs, the sensitivity, specificity, positive predictive value, and negative predictive value for differentiating between the LGIN and control groups were 24.8%, 97.3%, 78.3%, and 76.6%, respectively. The sensitivity (84.1%) and negative predictive value (92.4%) were significantly improved by combining EANA with types IV-VI pit pattern. The intervening part and mean gray value of glands, representing microsurface features and microvascular variation, were significantly larger or higher in EANA lesions than in the surrounding non-neoplastic mucosa. LGIN with EANA was more likely to be present in lesions of type 0-IIa. In addition, the prevalence of EANAs in EGC was 16.7%. CONCLUSION: An EANA could be used as an auxiliary indicator for a diagnosis of LGIN in suspected lesions. It could also play a potential assistive role in the diagnosis of EGC lesions.