Microscopy, confocal; Esophageal neoplasms; Barrett esophagus

Probe-based confocal laser endomicroscopy (pCLE) enables real-time histopathological assessment during endoscopic procedures to evaluate epithelial and subepithelial structures with a 1000x magnification. It may be used in various localizations not only in the digestive tract, but its role in clinical practice is still a matter of discussion. The main advantages of pCLE compared to standard biopsies may be: 1) real-time diagnosis; 2) which may be done by the endoscopist; and 3) a larger evaluated area compared to standard biopsies. In theory, pCLE has the potential to eliminate the need for biopsy. However, pCLE cannot replace standard biopsies at this time, among others, standard forceps biopsies are presently more cost-effective. pCLE may be used to enhance the diagnostic arsenal and improve mucosal visualization and evaluation in patients with Barrett's esophagus (BE), with visible esophageal lesions and in patients undergoing surveillance endoscopy after endoscopic treatment of BE related neoplasia. pCLE requires sufficient training and use of validated classifications systems. At present, the majority of endoscopic centers do not use pCLE routinely and no guidelines recommend its routine use for patients with different esophageal diseases, although pCLE is (in selected indications) reimbursed in some countries. This article describes the principle and performance of pCLE and reviews its use in patients with BE and early esophageal neoplasia.