MKI67 and cutaneous lupus erythematosus: The histopathological picture should not create particular problems of differential diagnosis, as the aggregates of PDCs are morphologically and phenotypically mature, with a low Ki67+ and loss of TdT immunoexpression, but, sometimes, it is possible to have diagnostic difficulties due to the fact that PDCs can simulate an inflammatory dermatitis such as cutaneous lupus erythematosus [45,52].