Endoscopic diagnosis of pharyngeal carcinoma by NBI.

Head and neck cancer, especially pharyngeal cancer, frequently co-exist with esophageal cancer, but pharyngeal cancer has proven difficult to detect in such cases before its progression to an advanced stage. Several recent reports have indicated that narrow-band imaging (NBI) endoscopy with magnification is able to improve the detection of superficial pharyngeal cancer. NBI is a relatively new optical technology based on limiting the depth of light penetration into the mucosa. The recognition of these lesions is dramatically improved and the microvascular structure of the mucosal surface is significantly enhanced by NBI. As a result, NBI enables more accurate diagnosis and increases the detection rate of superficial pharyngeal cancer. This particular field has only been developed in recent years, however, and there are still a number of problems that need to be addressed in the future. It will be necessary to accumulate and evaluate resected specimens and follow up patients in order to establish the appropriate criteria for curative endoscopic treatment in these patients. The ease in using NBI in combination with this new diagnostic concept based on microvascular changes makes NBI suitable for worldwide use in the future.