Progress in endoscopic imaging of gastrointestinal tumors

New technologies in the form of high-magnification or "zoom" endoscopy complemented by chromoscopic agents or Narrow Band Imaging permit early detection of neoplastic lesions, particularly flat and depressed types. Detailed characteristics of the mucosal surface can be obtained, enabling an in vivo "optical biopsy" to make an instant diagnosis at endoscopy, previously possible only by using histological or cytological analysis. Advances in fiber optics, light sources, detectors, and molecular biology have led to the development of several novel methods for tissue evaluation in situ.

Promising imaging techniques include fluorescence endoscopy, optical coherence tomography, confocal microendoscopy, molecular imaging, and light scattering and Raman spectroscopy.

These techniques probably are able to replace conventional biopsy in the near future, but the endoscopists should become increasingly more familiar with histopathologic findings.