Mycosis fungoides mimicking erysipelas

Mycosis fungoides may rarely simulate facial erysipelas. In a patient with that clinical presentation, a biopsy specimen revealed a diffuse dermal infiltrate with numerous neutrophils that also mimicked erysipelas histopathologically. The diagnosis of mycosis fungoides was made on the basis of atypical lymphocytes with focal epidermo- and folliculotropism. It was confirmed by typical findings of mycosis fungoides in a second biopsy from a clinically inconspicuous patch. An identical T-cell receptor gamma-gene rearrangement was detected in lymphocytes of both biopsy specimens.