Horizontal Histopathology Correlation with In Vivo Reflectance Confocal Microscopy in Inflammatory Skin Diseases: A Review

Horizontal histopathological sections (HHSs) have been reported to show a strong correlation with images obtained via in vivo reflectance confocal microscopy (RCM), as both reflect the same horizontal plane of the skin. Although vertical histopathology remains the diagnostic gold standard for most neoplastic and inflammatory skin diseases, HHSs represent a useful tool to validate the RCM features of some inflammatory disorders, including psoriasis, discoid lupus erythematosus, and eczema. The aim of the present review is to summarize the state of the art on the existing correlations between HHS and RCM in this field and to emphasize that RCM may represent a useful diagnostic tool to discriminate between diseases with similar clinical presentations.