Abstract: 【Abstract】 Objective To analyze consistency between histopathological and reflectance confocal microscopy (RCM) characteristics of early-stage mycosis fungoides（MF）, and to evaluate the value of RCM in assisting the pathological diagnosis of early-stage MF and the feasibility of dynamic monitoring of treatment response with RCM. Methods From January 2014 to January 2018, 40 cases of clinically suspected MF were collected from Department of Dermatology, Third People′s Hospital of Hangzhou, including 26 males and 14 females, and their age was 47.0 ± 17.6 years. According to the summarized RCM characteristics of early-stage MF, biopsy sites were preliminarily located, and then a histopathological examination was performed. The RCM and pathological features of MF were compared. In addition, a combination therapy with narrowband ultraviolet B and interferon was performed in patients with confirmed MF. Targeted lesions were followed up with RCM for 9 months, and then therapeutic efficacy was evaluated. Results Among the 40 cases of clinically suspected MF, 8 were preliminarily diagnosed as typical MF, 18 as suspected MF, and 14 were excluded according to the RCM characteristics; according to the pathological features, 12 could be diagnosed as typical MF, 14 as suspected MF, and 14 were excluded. Consistency analysis showed that the kappa coefficient between RCM classification and pathological diagnosis was 0.848（P < 0.01）. The consistency of epidermal infiltration of mildly refractive cells was the highest between RCM and pathological findings （kappa coefficient = 1, P = 0.005）, followed by dermal fibrosis at the erythema stage （kappa coefficient = 0.714, P = 0.035）. The RCM characteristics of MF gradually returned to normal during treatment, but atypical lymphocytes still existed when clinical lesions completely regressed. Conclusion RCM can be used for pathological localization of suspected MF lesions in the early stage, and for dynamic monitoring of therapeutic efficacy in MF.

Key words: Mycosis fungoides, Microscopy, confocal, Diagnosis, Treatment outcome, Monitor