Endoscopic cytoscopy is one of the new methods that aims to offer a very detailed image of the gastrointestinal mucosa. This method enables magnification of the mucosa under investigation up to 1 200x and it is the only endoscopic method that provides a very detailed chromatic picture of the morphological struc-ture of the mucosa, its cells, including nuclei, nucleoli, etc, in vivo. The investigation takés pláce during routine endoscopy and enables detection of possible inflammatory, preneoplastic and malignant changes of the gastrointestinal mucosa. Very good cooperation with a pathologist is very important. The method is suitable for investigation of the stomach, large bowel and particularly the oesophagus. Endocytoscopy is particularly applicable in patients where a biopsy is associated with an increased risk of bleeding.

        Key words: endoscopy, endoscopic cytoscopy, morphologic changes of mucosa