High-resolution narrow band imaging endoscopy

Oesophageal, gastric and colorectal neoplasms made up 24% of worldwide cancer mortality in 2002.1 Early detection of these neoplasms or their precursors may be the only chance to reduce this high mortality. Endoscopy is currently the initial procedure used for early detection of gastrointestinal (GI) cancers worldwide. The endoscopic appearance of early cancers is described as 9superficial9, and was first described in Japan for gastric cancer. The Japanese Gastric Cancer Association divides these superficial lesions into three types: type I polypoid, type II non-polypoid and nonexcavated, and type III non-polypoid with an ulcer (Figure 1).2 The type I is further divided into Ip for pedunculated lesions and Is for sessile lesions, while type II is subdivided into IIa for slightly elevated lesions, IIb for completely flat lesions, and IIc for slightly depressed lesions.2 This classification is the result of meticulous work by Japanese endoscopists who were facing with the high burden of gastric cancer, which develops almost exclusively from flat precursors.3 Thus, learning to identify subtle superficial abnormalities, such as discoloration of the mucosa (pale or red), helped to increase the recognition of mucosal and submucosal lymph node-negative gastric cancers (from 25% in 1975-1977 to 50% in 1993-1995)4 and improved survival in this patient population.5