[Confocal endomicroscopy for differential diagnosis of indented gastric lesions]

Confocal endomicroscope (CEM) is a newly developed endoscope based on the integration of a confocal laser scanning microscope at the distal tip of a conventional video endoscope. It can visualize living tissue at a cellular level. The aim of the present study was to assess the value of CEM for prediction of the histopathology of gastric depressed-type lesions during endoscopy.

Forty-three patients with gastric depressed-type lesions underwent CEM and 51 depressed-type lesions were examined. Confocal diagnosis was made according to cellular and gastric pit morphology and compared with conventional histopathologic findings of corresponding biopsy specimens from the observed sites in a prospective and double-blinded fashion.

The marginal and/or middle areas of every depressed-type lesion were examined by confocal imaging and a total of 4872 confocal images were obtained from 172 locations. Fluorescein sodium aided CEM to yield clear fluorescent images in vivo which allowed detailed analysis of surface and subsurface cellular and gastric pit architecture. A total of 46 biopsy specimens from 19 patients were diagnosed as gastric cancer. Confocal images had a sensitivity of 95.7%, a specificity of 97.6%, and accuracy of 97.1% for gastric cancer.

CEM can provide virtual histopathology of gastric cancer with high accuracy during endoscopy and it is of potential value for the differential diagnosis of gastric depressed-type lesions and early detection of gastric cancer.