Brown slits for colorectal adenoma crypts on conventional magnifying endoscopy with narrow band imaging using the X1 system

Figure 2 Representative images of “slit-like lumens” and “brown slits” in a low-grade tubular adenoma using endocytoscopy. A set of an endocytoscope (CF-H290EC), X1 system, and 4K 32-inch monitor was used. A, B: White light imaging observation; C, D: Narrow band imaging observation; A, C: Conventional (100 ×) magnifying observation. The yellow box represents the site for full-zoom observation; B, D: Full-zoom (790 ×) magnifying observation; D: Slit-like lumens were observed (blue arrows). The microvessels were clearly observed surrounding the slit-like lumen and showed a vessel network; C: A “brown slit” sign was observed (pink arrows); B: Slit-like lumens were obscurely observed (blue arrows).