Prospective replacement of magnifying endoscopy by a newly developed endocytoscope, the 'GIF-Y0002'.

Endocytoscopy has the potential to reduce the need for histologic examination of biopsy specimens in cases of esophageal squamous cell carcinoma. Up to now, two types of endocytoscope have been used: the probe type and the integrated type. In this study we examined the utility of a newly developed endocytoscope, the 'GIF-Y0002,' which has a single lens allowing consecutive magnification from the conventional endoscopy level up to ×380. Using the GIF-Y0002, we examined 24 examples of normal esophageal mucosa to clarify the appearance of the microvasculature of the normal squamous epithelium in vivo. We also examined 11 cases of esophageal cancer in the same way, employing methylene blue as a vital dye to stain the surface cells. In normal squamous epithelium, we clarified the relationship between the subepithelial capillary network, IPCLs and subepithelial venules. With methylene blue staining, we observed typical squamous cells (low nuclear density and low N/C ratio without nuclear abnormality). When cancerous lesions were observed using lower-power magnification, we were able to visualize their microvascular architecture to the same extent as when conventional magnifying endoscopy was used. Furthermore, at higher magnification, we were able to visualize the features of blood flow in both superficial and advanced cancer. Methylene blue staining revealed an increase of nuclear density in all cases of cancer. The pathologist agreed to omit biopsy histology in 81.8% (9/11) of cancer cases considering the nuclear density and nuclear abnormality. The GIF-Y0002 provides information on cell abnormality in addition to the features revealed by currently available magnifying endoscopy.