A study of pathological characteristics and <i>BRAF</i> V600E status in Langerhans cell histiocytosis of Vietnamese children

Abstract

Background: Langerhans cell histiocytosis (LCH) is more common in children than adults and involves many organs. In children, the BRAF V600E mutation is associated with recurrent and high-risk LCH. Methods: We collected paraffin blocks of 94 pediatric LCH patients to detect BRAF V600E mutation by sequencing. The relationship between BRAF V600E status and clinicopathological parameters were also critically analyzed. Results: BRAF V600E mutation exon 15 was detected in 45 cases (47.9%). Multiple systems LCH showed a significantly higher BRAF V600E mutation rate than a single system (p = .001). No statistical significance was evident for other clinical characteristics such as age, sex, location, risk organs involvement, and CD1a expression. Conclusions: In Vietnamese LCH children, the proportion of BRAF V600E mutational status was relatively high and related to multiple systems.

Pathologic characteristics of histiocytic and dendritic cell neoplasms

“…In cases of central nervous system Langerhans cell histiocytosis (CNS-LCH), LCH-associated neurodegenerative diseases (LCH-ND) progressively develop in up to 10% of patients. In these cases, inflammatory infiltrates have been described, composed of foamy macrophages, CD1a + cells, and perivascular infiltrates of mononuclear cells expressing the BRAF V600E protein, along with neurodegeneration or demyelination [ 1 – 3 , 5 , 6 , 23 – 26 ].…”

“…Through the MAP pathway, phosphorylation and nuclear translocation of ERK occur, acting as a transcription factor for cell proliferation and survival. Mutations in MAPK pathway genes are present in approximately 85% of LCH cases, with the BRAF V600E mutation occurring in about 50-60% of cases [4,26,46,[65][66][67][68]. BRAF mutations are also correlated with high-risk LCH [46,69].…”