Mycosis fungoides: reflectance confocal microscopy and its role in the diagnosis

Background Mycosis fungoides (MF), a T-cell lymphoma, is the most common variant of primary cutaneous lymphomas. The discrete clinical aspect of the early patch-stage and an overlapping clinical presentation with other erythematosquamous skin diseases make the diagnosis of MF challenging. Histopathology is the gold standard for the diagnosis of MF. However, in early stages, MF can simulate inflammatory diseases, presenting reactive lymphocytes and absence of lymphocytic cytologic atypia. Consecutive biopsies are often necessary from several clinically suspect sites. Previous studies evaluated Reflectance Confocal Microscopy (RCM) as a promising tool for MF diagnosis because it offers the opportunity to analyze skin structures non-invasively at a ‘quasi-histopathologic’ resolution and to guide the most representative site for biopsy.