LCH : Immunophenotype
Immunophenotype of Langerhans Cells in Langerhans Cell Histiocytosis (LCH): POSITIVE MARKERS: CD1a - surface and paranuclear staining; langerin (CD207) granular cytoplasmic staining, the most sensitive and specific marker for Langerhans cells; S-100 protein - nuclear and cytoplasmic. CD1a/CD207/S100 panel is highly specific and has largely replaced ultrastructural demonstration of Birbeck granules for the diagnosis of LCH. VE1 antibody which recognizes BRAF V600E mutation is positive in the same cells expressing CD207. There is paranuclear dot-like positivity for CD68 and HLA-DR. Vimentin is strongly positive. Ki-67 immunoreactivity is highly variable. NEGATIVE MARKERS: CD45 (may be weakly +), lysozyme (may be weakly +), B- and T-cell lineage markers (except CD4), follicular dendritic cell markers (CD21, CD35), CD15, and CD30.