scholarly journals Recurrent BRAF mutations in Langerhans cell histiocytosis

Blood ◽  
2010 ◽  
Vol 116 (11) ◽  
pp. 1919-1923 ◽  
Author(s):  
Gayane Badalian-Very ◽  
Jo-Anne Vergilio ◽  
Barbara A. Degar ◽  
Laura E. MacConaill ◽  
Barbara Brandner ◽  
...  
Keyword(s):  
Langerhans Cells ◽  
Langerhans Cell Histiocytosis ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Braf V600e ◽  
Neoplastic Disease ◽  
Braf Mutations ◽  
Multiple Organs ◽  
Mitogen Activated Protein ◽  
Formalin Fixed Paraffin Embedded

Abstract Langerhans cell histiocytosis (LCH) has a broad spectrum of clinical behaviors; some cases are self-limited, whereas others involve multiple organs and cause significant mortality. Although Langerhans cells in LCH are clonal, their benign morphology and their lack (to date) of reported recurrent genomic abnormalities have suggested that LCH may not be a neoplasm. Here, using 2 orthogonal technologies for detecting cancer-associated mutations in formalin-fixed, paraffin-embedded material, we identified the oncogenic BRAF V600E mutation in 35 of 61 archived specimens (57%). TP53 and MET mutations were also observed in one sample each. BRAF V600E tended to appear in younger patients but was not associated with disease site or stage. Langerhans cells stained for phospho-mitogen–activated protein kinase kinase (phospho-MEK) and phospho-extracellular signal-regulated kinase (phospho-ERK) regardless of mutation status. High prevalence, recurrent BRAF mutations in LCH indicate that it is a neoplastic disease that may respond to RAF pathway inhibitors.

scholarly journals NFB-05. AN UNUSUAL PRESENTATION OF RECURRENT LANGERHANS CELL HISTIOCYTOSIS OF THE CRANIOFACIAL BONES IN A PATIENT WITH NEUROFIBROMATOSIS TYPE I

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii418-iii418
Author(s):  
Blake Chaffee ◽  
Alexis Judd ◽  
Sarah Rush ◽  
Erin Wright
Keyword(s):  
Langerhans Cell Histiocytosis ◽  
Malignant Tumors ◽  
Neurofibromatosis Type ◽  
Mapk Signaling ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Type I ◽  
Braf Mutations ◽  
Surveillance Imaging ◽  
Mitogen Activated Protein

Abstract Neurofibromatosis type 1 (NF1), predisposes patients to benign and malignant tumors due to lack of suppression of the mitogen activated protein kinase (MAPK) signaling pathway. Langerhans cell histiocytosis (LCH) manifests in numerous ways, from localized lesions to multisystem organ involvement secondary to a constitutively active MAPK signaling cascade often driven by BRAF mutations. While both LCH and NF1 are characterized by overactive MAPK signaling, there are few reports of the two diseases occurring simultaneously. We report a novel case of a patient with underlying NF1 and recurrent LCH without a BRAFV600E mutation. She initially presented at 2 years of age with an aggressive appearing mass of the left temporal bone found on surveillance imaging. Pathology was consistent with Langerhans histiocytosis and she was treated with the LCH-III protocol for patients with high-risk LCH due to the location of her lesion. Five years after completion of therapy, MRI demonstrated development of a calvarial mass consistent with relapsed LCH in a new risk site. Lesional curettage was performed and pathology confirmed recurrence of LCH with juvenile xanthogranulomatous features. BRAF testing of blood and the lesion were negative for any BRAF alterations. Further genomic evaluation of the tumor is in progress at this time to evaluate for other known mutations associated with LCH. The patient is currently receiving monthly cytarabine treatment which she has tolerated to date. Our patient represents a unique presentation of recurrent LCH in a patient with NF1 and further molecular evaluation may help identify other drivers of LCH activation.

scholarly journals Three decades of progress from surgery to medical therapy for isolated neuroaxis BRAF V600E–positive Langerhans cell histiocytosis management: illustrative case

2021 ◽  
Vol 1 (19) ◽  
Author(s):  
Nallammai Muthiah ◽  
Kamil W. Nowicki ◽  
Jennifer L. Picarsic ◽  
Michael P. D’Angelo ◽  
Daniel F. Marker ◽  
...  
Keyword(s):  
Langerhans Cell Histiocytosis ◽  
Mapk Pathway ◽  
Clinical Manifestations ◽  
Tumor Burden ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Braf V600e ◽  
Illustrative Case ◽  
Surgical Interventions ◽  
Mitogen Activated Protein

BACKGROUND “Langerhans cell histiocytosis” (LCH) is a term that encompasses single-system or multisystem disorders traditionally characterized by a proliferation of clonal CD1a+/CD207+ myeloid-derived histiocytes. In most cases of LCH, mitogen-activated protein kinase (MAPK) pathway somatic mutations lead to near universal upregulation of phosphorylated extracellular signal-regulated kinase expression. The clinical manifestations of LCH are numerous, but bone involvement is common. Intracranial lesions, especially as isolated manifestations, are rare. OBSERVATIONS The authors presented the case of a long-term survivor of exclusive intracranial LCH that manifested with isolated craniofacial bone and intraparenchymal central nervous system recurrences, which were managed with 3 decades of multimodal therapy. The patient was initially diagnosed with LCH at age 2 years, and the authors documented the manifestations of disease and treatment for 36 years. Most of the patient’s treatment course occurred before the discovery of BRAF V600E. Treatments initially consisted of chemotherapy, radiosurgery, and open resections for granulomatous LCH lesions. Into young adulthood, the patient had a minimal disease burden but still required additional radiosurgical procedures and open resections. LESSONS Surgical treatments alleviated the patient’s immediate symptoms and allowed for tumor burden control. However, surgical interventions did not cure the underlying, aggressive disease. In the current era, access to systemic MAPK inhibitor therapy for histiocytic lesions may offer improved outcomes.

scholarly journals High prevalence of somatic MAP2K1 mutations in BRAF V600E–negative Langerhans cell histiocytosis

Blood ◽  
2014 ◽  
Vol 124 (10) ◽  
pp. 1655-1658 ◽  
Author(s):  
Noah A. Brown ◽  
Larissa V. Furtado ◽  
Bryan L. Betz ◽  
Mark J. Kiel ◽  
Helmut C. Weigelin ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Genome Sequencing ◽  
High Frequency ◽  
Langerhans Cell Histiocytosis ◽  
Langerhans Cell ◽  
Braf V600e ◽  
Braf Mutations ◽  
Key Points ◽  
High Prevalence

Key Points Targeted genome sequencing reveals high-frequency somatic MAP2K1 mutations in Langerhans cell histiocytosis. MAP2K1 mutations are mutually exclusive with BRAF mutations and may have implications for the use of BRAF and MEK targeted therapy.

Pulmonary Langerhans Cell Histiocytosis

2020 ◽  
Vol 41 (02) ◽  
pp. 269-279
Author(s):  
Brian Shaw ◽  
Michael Borchers ◽  
Dani Zander ◽  
Nishant Gupta
Keyword(s):  
Langerhans Cell Histiocytosis ◽  
Treatment Options ◽  
Skin Lesions ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Myeloid Neoplasm ◽  
Cystic Lung ◽  
Pulmonary Langerhans Cell Histiocytosis ◽  
Mitogen Activated Protein ◽  
The Central Nervous System

AbstractPulmonary Langerhans cell histiocytosis (PLCH) is a diffuse cystic lung disease that is strongly associated with exposure to cigarette smoke. Recently, activating pathogenic mutations in the mitogen-activated protein kinase pathway have been described in the dendritic cells in patients with PLCH and have firmly established PLCH to be an inflammatory myeloid neoplasm. Disease course and prognosis in PLCH are highly variable among individual patients, ranging from spontaneous resolution to development of pulmonary hypertension and progression to terminal respiratory failure. A subset of patients with PLCH may have extrapulmonary involvement, typically involving the skeletal system in the form of lytic lesions, skin lesions, or the central nervous system most commonly manifesting in the form of diabetes insipidus. Smoking cessation is the cornerstone of treatment in patients with PLCH and can lead to disease regression or stabilization in a substantial proportion of patients. Further insight into the underlying molecular pathogenesis of PLCH has paved the way for the future development of disease-specific biomarkers and targeted treatment options directed against the central disease-driving mutations.

High Prevalence of BRAF V600E Mutations in Langerhans Cell Histiocytosis of Head and Neck in Chinese Patients

2019 ◽  
Vol 27 (8) ◽  
pp. 836-843
Author(s):  
Xiaoxiao Liu ◽  
Ye Zhang ◽  
Chuan-Xiang Zhou
Keyword(s):  
Head And Neck ◽  
Langerhans Cells ◽  
Langerhans Cell Histiocytosis ◽  
Neck Region ◽  
Braf V600e Mutation ◽  
Langerhans Cell ◽  
Braf V600e ◽  
Chinese Patients ◽  
Clonal Proliferation ◽  
High Prevalence

Langerhans cell histiocytosis (LCH) is characterized by clonal proliferation of Langerhans cells and has been classified as a hematolymphoid tumor. BRAF V600E mutation was found to be frequent in LCH; however, it has also been reported that Asia patients with LCH tend to show a lower rate of BRAF V600E mutation. In this study, we found LCH from the head and neck region often involved bone especially the posterior of the mandible and presented a high prevalence of BRAF V600E mutation in Chinese patients. Our findings also showed immunohistochemical detection correlated very well to DNA sequencing of BRAF alterations, which may be useful in the diagnosis of LCH, especially in cases with a low proportion of Langerhans cells, and BRAF inhibitors might be a treatment option for patients with LCH harboring BRAF V600E mutation.

scholarly journals Results of TETimaX Trial of Langerhans Cell Histiocytosis Treatment and Perspectives on the Role of Imatinib Mesylate in the Era of MAPK Signaling

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1759
Author(s):  
Liliana Montella ◽  
Margaret Ottaviano ◽  
Vittorio Riccio ◽  
Fernanda Picozzi ◽  
Gaetano Facchini ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitor ◽  
Langerhans Cell Histiocytosis ◽  
Kinase Inhibitor ◽  
Growth Factor Receptor ◽  
Mapk Signaling ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein

Langerhans cell histiocytosis (LCH) is a rare disease that has a variable clinical presentation and unpredictable behavior. Until recently, therapeutic options were limited. Insights into the role of mitogen-activated protein kinase (MAPK) signaling have allowed the increased use of targeted treatments. Before the advent of drugs that interfere with this pathway, investigations concerning the tyrosine kinase inhibitor imatinib opened the way to a rationale-based therapeutic approach to the disease. Imatinib block the binding site of ATP in the BCR/ABL protein and is also a platelet-derived growth factor receptor (PDGFR) and a KIT (CD117) kinase inhibitor. A case of refractory LCH with brain involvement was reported to be successfully treated with imatinib. Thereafter, we further explored the role of this tyrosine kinase inhibitor. The present study is composed of an immunohistochemical evaluation of PDGFRβ expression and a clinical evaluation of imatinib in a series of LCH patients. In the first part, a series of 10 samples obtained from LCH patients was examined and a strong immunohistochemistry expression of PDGFRβ was found in 40% of the cases. In the clinical part of the study, five patients were enrolled. Long-lasting disease control was obtained. These results may suggest a potential role for this drug in the current age.

scholarly journals Langerhans Cell Histiocytosis: a Case Report

2013 ◽  
Vol 5 (2) ◽  
pp. 74-86
Author(s):  
Mirjana Paravina ◽  
Dragan Jovanović ◽  
Milenko Stanojević ◽  
Ljiljana Nikolić
Keyword(s):  
Langerhans Cells ◽  
Langerhans Cell Histiocytosis ◽  
Early Stage ◽  
Fatal Outcome ◽  
Langerhans Cell ◽  
Neoplastic Disease ◽  
Multisystem Disease ◽  
Organ Systems ◽  
The Right

Abstract Langerhans cell histiocytosis is a disease which results from accumulation or proliferation of a clonal population of cells with the phenotype of Langerhans cells arrested at an early stage of activation that are functionally deficient. The etiology and pathogenesis of the disorder are still unknown. There are ongoing investigations to determine whether it is a reactive or a neoplastic disease. The fact is that neoplastic and reactive processes may have many clinical and pathological similarities. Some emphasize the role of “cytokine storm” in Langerhans cells. Further studies are necessary in all areas, from the etiology and pathogenesis to diagnosis and therapy. Langerhans cell histiocytosis primarily affects bones, but less commonly it may involve other organ systems, or present as a multisystem disease. The clinical course is variable, from benign forms with spontaneous resolution, to chronic disseminated forms with fatal outcome. This is a report of a 29-year-old man with Langerhans cell histiocytosis with an onset at the age of 8, which later progressed to a multisystem disease. Apart from lesions on the skin and exposed mucous membranes, the patient also presented with: diabetes insipidus, granuloma of the right femur and slight bulbar protrusion of the right eye. The patient experienced spontaneous pneumothorax on two occasions. The diagnosis of Langerhans cell histiocytosis was histologically confirmed using electron microscopy by presence of Birbeck granules in the histiocytes. A favorable therapeutic response was obtained after systemic corticosteroid therapy.

scholarly journals RAF/MEK/extracellular signal–related kinase pathway suppresses dendritic cell migration and traps dendritic cells in Langerhans cell histiocytosis lesions

2017 ◽  
Vol 215 (1) ◽  
pp. 319-336 ◽  
Author(s):  
Brandon Hogstad ◽  
Marie-Luise Berres ◽  
Rikhia Chakraborty ◽  
Jun Tang ◽  
Camille Bigenwald ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Langerhans Cell Histiocytosis ◽  
Mapk Pathway ◽  
Mek Inhibitor ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Phagocytic Cells ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Myeloid Neoplasia

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia characterized by granulomatous lesions containing pathological CD207+ dendritic cells (DCs) with constitutively activated mitogen-activated protein kinase (MAPK) pathway signaling. Approximately 60% of LCH patients harbor somatic BRAFV600E mutations localizing to CD207+ DCs within lesions. However, the mechanisms driving BRAFV600E+ LCH cell accumulation in lesions remain unknown. Here we show that sustained extracellular signal–related kinase activity induced by BRAFV600E inhibits C-C motif chemokine receptor 7 (CCR7)–mediated DC migration, trapping DCs in tissue lesions. Additionally, BRAFV600E increases expression of BCL2-like protein 1 (BCL2L1) in DCs, resulting in resistance to apoptosis. Pharmacological MAPK inhibition restores migration and apoptosis potential in a mouse LCH model, as well as in primary human LCH cells. We also demonstrate that MEK inhibitor-loaded nanoparticles have the capacity to concentrate drug delivery to phagocytic cells, significantly reducing off-target toxicity. Collectively, our results indicate that MAPK tightly suppresses DC migration and augments DC survival, rendering DCs in LCH lesions trapped and resistant to cell death.

scholarly journals Targeted Therapy for Colorectal Cancers With Non-V600 BRAF Mutations: Perspectives for Precision Oncology

2018 ◽  
pp. 1-12 ◽  
Author(s):  
Matthew Dankner
Keyword(s):  
Targeted Therapy ◽  
Mitogen Activated Protein Kinase ◽  
Braf V600e ◽  
Colorectal Cancers ◽  
Precision Oncology ◽  
Braf Mutations ◽  
Egfr Inhibition ◽  
Mitogen Activated Protein ◽  
Braf Mutant ◽  
Kinase Pathway

BRAF mutations are found in up to 10% of colorectal cancers (CRC). Whereas the majority of BRAF mutant CRCs harbor V600 mutations, up to 25% express non-V600 BRAF mutations. It has been established that BRAF V600E mutations in CRC predict unresponsiveness to epidermal growth factor receptor (EGFR) inhibition—cetuximab and/or panitumumab—as a result of the constitutive activation of the mitogen-activated protein kinase pathway downstream of EGFR signaling. As more centers begin using next-generation sequencing assays to detect BRAF mutations, oncologists are more frequently confronted with treating patients with non-V600 BRAF mutations. In many instances, clinicians may be hesitant to use EGFR inhibitors for these patients, as it is largely assumed that tumors with non-V600 BRAF mutations activate the mitogen-activated protein kinase pathway in a similar manner to RAS or BRAF V600E mutations and would therefore be equally refractory to EGFR inhibition; however, the evidence that currently exists to substantiate this claim is mixed and incomplete. Recent data demonstrate that non-V600 BRAF mutant CRC is a distinct clinical entity with a favorable prognosis compared with CRC with V600E mutations. Preclinical data and several case reports suggest that a subset of BRAF non-V600 mutations that impair the protein's kinase activity may in fact confer heightened sensitivity to EGFR inhibition because of dependency on upstream receptor tyrosine kinase signaling. This review summarizes the clinical characteristics and targeted therapy approaches for non-V600 BRAF mutant CRCs, speculates on the value of non-V600 BRAF mutations as predictive biomarkers of responsiveness to EGFR inhibitors, and highlights outstanding questions in this emerging area of precision oncology.

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