Cutaneous Langerhans cell histiocytosis : The spectrum of a rare cutaneous neoplasia.

Langerhans cell histiocytosis (LCH) is a rare disorder that is now recognized as a true malignancy of dendritic Langerhans cells. Various somatic mutations have been discovered for BRAF and MAP kinases. The clinical variability is remarkable. A very rare variant is cutaneous LCH without internal organ manifestations. We present a case series of cutaneous LCH illustrating the spectrum of clinical symptoms, treatment, and disease course. Cutaneous LCH needs a careful investigation of possible internal involvement and a long follow-up since second malignancies may develop over time. Overtreatment should be avoided, since too-aggressive treatment will not improve the outcome.