In vivo observation of living cancer cells in the esophagus, stomach, and colon using catheter-type contact endoscope, "Endo-Cytoscopy system".

A catheter-type endomicroscope has been developed with a maximum magnifying power of 1100 times. Living cancer cells in the esophagus, stomach, and colon were successfully observed in high-resolution images. The "Endo-Cytoscopy system" (prototype,Olympus Optical, Co., Tokyo, Japan) is a catheter-based probe capable of passage through the accessory channel of the endoscope(GIF-1T, Olympus). Methylene blue solution was used for vital staining of the in vivo gastrointestinal mucosa. Living cells in both normal mucosa and malignant tissue were clearly demonstrated in luminal organs. In particular, the nucleus, cell body, and nucleolus were clearly demonstrated with high-quality images similar to those of conventional cytology. This novel technology has the potential to provide an in vivo histologic diagnosis via "optical biopsy" and virtual histology.