Abstract:

Su Haihui, Chen Lixin, Gong Zekun, Guan Zhiwei, Wang Ji, Wang Ying, Lian Jia, Feng Xiaoyan, Hao Liangchen, Yuan Shiping, Wang Xiaoyan, Duan Zhihua. Department of Dermatology, Tianjin Children′s Hospital, Tianjin 300074, China Corresponding author: Su Haihui, Email: suhaihui2004@sina.com 【Abstract】 Objective To assess the reflectance confocal microscopic features of pediatric Langerhans cell histiocytosis （LCH）, and to evaluate the performance of RCM in the early diagnosis of pediatric LCH. Methods RCM was routinely performed to image lesions in 14 children with LCH before biopsy. Then, biopsy and histopathological examination were carried out at the sites determined according to RCM images. A comparison was conducted between the confocal microscopic and pathological findings. All the 14 cases were finally diagnosed based on histopathological and immunohistochemical examination results. Results RCM imaging in these patients showed that the epidermal structure was disorganized with spongiosis, infiltration of moderately refractive inflammatory cells and disappearance of normal honeycomb structures, slightly refractive cavernous or crateriform appearance was observed sometimes in the superficial epidermis and even stratum corneum; normal dermal papillary rings were obscure or absent with infiltration of multiple scattered moderately refractive inflammatory cells; plenty of bright hyper-refractive dendritic cells, which varied in size and shape, gathered into clusters in the dermis; moderately refractive inflammatory cells infiltrated the papillary and reticular dermis with the tangling and dilation of blood vessels giving a spherical or linear appearance in some regions. Histopathological examination and immunohistochemical staining for S100 and CD1a both demonstrated that the bright dendritic cells were activated Langerhans cells. RCM images were highly consistent with histopathological and immunohistochemical findings in these patients. Conclusion RCM, a non-invasive examination method, can facilitate the determination of biopsy sites, and promote the accuracy of pathological diagnosis of LCH.