Here we report a case of an <i>EGFR-</i>/<i>ALK-</i>/<i>BRAF+</i> metastatic adenocarcinoma patient who underwent lung biopsy for evaluation of upper-lobe predominant lung nodules revealed to represent pulmonary Langerhans cell histiocytosis (PLCH).
The current consensus is that PLCH represents a myeloid neoplasm with inflammatory properties: the myeloid tumour cells exhibit surface CD1a expression and up to 50% of the cells harbour activating BRAF or other MAPK mutations.
Lung transplantation is a therapeutic option for patients with advanced PLCH.The identification of the <i>BRAF<sup>V600E</sup></i> mutation in approximately half of Langerhans cell histiocytosis lesions, including PLCH, and other mutations of the mitogen-activated protein kinase (MAPK) pathway in a subset of lesions has led to targeted treatments (BRAF and MEK (MAPK kinase) inhibitors).
Given that the lesional cells of PLCH express BRAF in some patients, MAPKinase pathway-targeted treatment might be useful for therapy-resistant patients.
Seven of 25 (28%) PLCH cases were positive for BRAFV600E expression (age 45.3±8.1, 2 men); 6 of 7 cases with BRAF V600E expression were also positive by mutation analysis.
The current consensus is that PLCH represents a myeloid neoplasm with inflammatory properties: the myeloid tumour cells exhibit surface CD1a expression and up to 50% of the cells harbour activating BRAF or other MAPK mutations.
Lung transplantation is a therapeutic option for patients with advanced PLCH.The identification of the <i>BRAF<sup>V600E</sup></i> mutation in approximately half of Langerhans cell histiocytosis lesions, including PLCH, and other mutations of the mitogen-activated protein kinase (MAPK) pathway in a subset of lesions has led to targeted treatments (BRAF and MEK (MAPK kinase) inhibitors).
Here we report a case of an <i>EGFR-</i>/<i>ALK-</i>/<i>BRAF+</i> metastatic adenocarcinoma patient who underwent lung biopsy for evaluation of upper-lobe predominant lung nodules revealed to represent pulmonary Langerhans cell histiocytosis (PLCH).
Here we report a case of an <i>EGFR-</i>/<i>ALK-</i>/<i>BRAF+</i> metastatic adenocarcinoma patient who underwent lung biopsy for evaluation of upper-lobe predominant lung nodules revealed to represent pulmonary Langerhans cell histiocytosis (PLCH).
The results suggest that macrophage colony stimulating factor and platelet derived growth factor may have a role in the initiation or maintenance of pathological reactions in pulmonary histiocytosis X.