Magnifying endoscopy for diagnosing and delineating early gastric cancer.

We describe the basic principles and clinical usefulness of modern magnifying endoscopy techniques, using white-light imaging or narrow-band imaging, for precise diagnosis of small flat gastric cancers. Regarding technology, first, the resolution provided by the endoscope is important in order to consistently visualize the precise morphology of microvascular architecture, and second, the use of a distal attachment (soft hood or cap) is essential in order to maintain a constant distance between the tip of the scope and the mucosal surface. Regarding methodology, a systematic but simple classification system based on microvascular pattern and microsurface pattern (the "VS classification") is proposed. The technique based on the principles described here can be applied not only in routine endoscopic examination but also in the detailed preoperative assessment of the lateral extent of early gastric cancer, before endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD).