BRAF-V600E and Langerhans Cell Histiocytosis

LCH limited to skin and LCH affecting internal organs appear to originate from separate mutations with different degrees of risk for death.

Patients with Langerhans cells histiocytosis (LCH) accumulate CD207⁺ dendritic cells (DCs) in skin, vital organs, or both. Previously, experts considered these cells to be transformed or activated Langerhans cells, because many of them contain Birbeck granules or langerin. Recent studies dispute this; these Langerhans-like cells may be immature myeloid DC precursors. LCH prognosis depends on involvement of the internal organs, regardless of skin disease severity. If LCH involves bone marrow, liver, spleen, or other “high-risk” organs, patients have a >20% risk for related mortality; those with cutaneous disease alone have related mortality rates of almost zero.

Recent reports identify recurrent somatic mutations of BRAF-V600E in skin lesions…

Reviewing Author

Mark V. Dahl, MD

Disclosures

Consultant / Advisory board Ulthera, Inc.; AuBio LifeSciences, LLC; Paris Therapeutics

Equity Elorac, Inc.; Makucell, Inc.; Paris Therapeutics

Editorial boards UpToDate

Leadership positions in professional societiesNational Rosacea Society (Chairman, Medical Board)