Shinohara S, Funabiki K, Kikuchi M, et al. - Given that confocal laser endomicroscopy (CLE) is a technology that allows microscopic visualization of lesions in real-time (optical biopsy) and has been successfully applied for clinical use in gastroenterology, researchers described the characteristics of head and neck squamous cell carcinoma (HNSCC) compared with normal mucosa and established a methodology of in vivo real-time optical biopsy of HNSCCs. From 10 patients who underwent surgical resection, HNSCC tissues were acquired. Lower signals have been observed from auto-fluorescence images of cancer tissues than normal tissues with 473 nm laser excitation. A clear difference was found between cancer and normal mucosa in the uniformity of nuclear size and shape after acriflavine application. Real-time in vivo imaging using the newly developed CLE and conditions can be used without invasive biopsy to distinguish cancer tissue from normal mucosa.