Abstract: 【Abstract】 Objective To investigate dermoscopic, reflectance confocal microscopic （RCM） and histopathological features of trichoepithelioma. Methods A total of 23 outpatients with histopathologically confirmed trichoepithelioma were enrolled from Department of Dermatology, Wuhan No.1 Hospital between January 2017 and December 2018. Dermoscopic and RCM images were collected, and the consistency was analyzed between dermoscopic or RCM features and histopathological features. Results Among the 23 patients, 5 were male, and 18 were female. Their age was 39.5 ± 22.1 years. Histopathological examination showed that the tumor was well-circumscribed and surrounded by abundant fiber matrices, consisted of many basaloid cells forming clusters or interlacing cords with surrounding cells arranged in a fence-like pattern. Tumor cells differentiated into dermal papilla cells to different extents, and varying amounts of keratinous cysts were observed. RCM showed bud-like downward extension of cord-like cells at the dermo-epidermal junction in 8 patients, which tended to be arranged in a fence-like pattern; seemingly lobulating nodular tumor masses were scattered in the dermis in 18 patients, which appeared as extended hypoechoic structures, with no constriction gap between tumor masses and surrounding tissues; tumor masses were surrounded by moderately to highly refractive amorphous substance in 16 patients; characteristic hair papilla structures suspected to be derived from primary differentiation were observed in 16 patients; keratinous cysts were clearly observed in 20 patients. Dermoscopy clearly showed that homogeneous pearl-white structures in 20 patients, and linear telangiectasia in 10 patients. Conclusion RCM features of trichoepithelioma are highly consistent with its histopathological features, so reflectance confocal microscopy can serve as an efficient method for auxiliary and differential diagnosis.

Key words: Microscopy, confocal, Dermoscopy, Trichoepithelioma, Histopathology