LAUSR

The development of artificial intelligence (AI) systems in the field of colorectal endoscopy is currently booming, colorectal cancer being, by its frequency and severity, a serious public health concern. In terms of image analysis, AI is indeed able to perform many tasks automatically, including lesion detection, classification, and segmentation, and to combine them [1]. Lesion detection is thus the starting point of the whole chain to eventually choose the most appropriate patient treatment. Large-scale studies have demonstrated the superiority of AIassisted detection over the usual detection by gastroenterologists, mainly for the detection of sub-centimeter polyps [2, 3]. However, we have shown that a recent computer-aided detection (CADe) system such as the ENDO-AID software in combination with the EVIS X1 video column (Olympus, Tokyo, Japan) may have difficulties in the detection of flat lesions such as sessile serrated lesions (SSLs) and non-granular laterally spreading tumors [4, 5]. This represents a major challenge, because in addition to their shape being difficult for the human eye to identify in practice and where AI assistance would thus be of great value, these rare lesions are associated with advanced histology. Herein we report the case of a patient with a 2.5-cm pseudo-depressed nongranular laterally spreading tumor of the transverse colon not detected correctly by CADe (▶Fig. 1, ▶Video 1). This lesion included a 15-mm Kudo Vi demarcated area (▶Fig. 2, ▶Fig. 3). Pathological examination suggested an adenocarcinoma invading the muscularis mucosae (▶Fig. 4, ▶Fig. 5). It is essential for endoscopists to continue to properly analyze the colonic mucosal surface. It remains a major challenge for diagnostic endoscopy not to miss such flat lesions, which may be invasive cancers and for which endoscopic treatment could allow the patient to be cured.