 1. confocal endomicroscopy for the diagnosis of high-grade dysplasia and superficial esophageal adenocarcinoma in patients with Barretts esophagus 2 Diagnosis of superficial esophageal squamous cell carcinoma in patients with head and neck cancer by confocal endomicroscopy 3 Detect the presence of premalignant lesions in the gastric stump in patients with reflux alkaline gastritis after partial gastrectomy 4. detect lesions in the gastric mucosa of patients with familial history of gastric cancer 5 Biliary Strictures: differential diagnosis by confocal endomicroscopia 6 confocal Endomicroscopy of cystic neoplasms of the pancreas 7 Contribution of confocal endomicroscopy for the differential diagnosis of colorectal polyps The project aims to deploy the structure of the Confocal endomicroscopy Endoscopy ICESP, for performing in vivo histological examinations of the digestive tract, biliary tract and pancreas. All research groups involved in the early detection of tumors of the esophagus, stomach, biliary tract, pancreas, colon and rectum may benefit from the implementation of this methodology. 