Plasmacytoid dendritic cells in granulomatous variant of mycosis fungoides.

INTRODUCTION

Granulomatous mycosis fungoides (MF) is a rare variant in which granulomas are associated with other typical signs of MF. Its prognosis is worse than that of classical MF. Plasmacytoid dendritic cells (PDCs) are a subset of interferon-producing dendritic cells that link the innate and the adaptative immune responses. They have also been related to tolerance to certain tumors such as melanoma.

MATERIALS AND METHODS

In this article, we examined for the presence of CD123+ PDC in six cases of granulomatous MF from our archives.

RESULTS

We found clusters of 10 or more positive cells in three of six cases of granulomatous MF (two women and a man, in their sixth and seventh decade). Although in two of these three cases the granulomatous response was extensive, in the other, it only represented 10% of the infiltrate of the biopsy. In all three cases, the granulomas were epithelioid, sarcoidal type.

CONCLUSIONS

CD123+ PDC can be identified in granulomatous MF. The pathogenic and prognostic role of this finding requires further clarification.