Granulomatous mycosis fungoides.

We report a new observation of granulomatous mycosis fungoides. The diagnosis was able to be made only after performing multiple biopsies during the course of the disease. Initial evolution was rapidly favourable with electrontherapy. A granulomatous reaction is, except in Hodgkin's disease, a rare phenomenon in lymphoproliferative disorders, particularly in cutaneous T cell lymphoma. This variant of mycosis fungoides raises the problem of the histological differentiation from other granulomatous dermatoses, mainly sarcoidosis. Its prognostic significance is disputed and its pathogenesis remains unknown.