Mutation of BRAF-V600E gene and expression of cyclin D1 protein in Langerhans cell histio-cytosis and their clinical significance
Objective To investigate the mutation of BRAF-V600E gene and expression of cyclin D1 protein in LCH and to observe their clinical significance.Methods The clinical and pathological features,immunophenotype,mutation of BRAF-V600E gene and prognosis in 5 cases of LCH were evaluated from November 2017 to July 2023 with review of the relevant literature.Results Three cases were male,and 2 were female,aged from 6-59 years.Microscopically,the le-sions were composed of histiocytes with obvious nuclear groove,associated with a variable number of eosinophils,lympho-cytes and plasma cells.Immunophenotypically,CDla,Langerin,S-100 and cyclin D1 were positive,Ki-67 positive index was 1%-10%.BRAF-V600E gene mutation was detected in one case.Conclusion LCH is a very rare histiocytosis tu-mor.Due to the low incidence and lack of systematic knowledge,the clinical understanding of LCH is insufficient,thus the rate of misdiagnosis is high.Cyclin D1 immunohistochemistry and BRAF-V600E gene mutation may be useful as novel di-agnostic markers of neoplasia in LCH.These markers might be used to support BRAF inhibitor therapy.