This is a prospective randomised study investigating the use of chromoendoscopy and confocal laser endomicroscopy for the detection of preneoplastic neoplasm in patients at high-risk of gastric cancer. Patients are randomised to undergo upper endoscopy using either confocal laser endomicroscopy or standard whitelight endoscopy to investigate for gastric preneoplastic and neoplastic lesions.Results are compared to histopathologic diagnosis made on biopsies obtained during endoscopy.