denotes an abstract that is clinically relevant.
denotes that this is a ticketed session.
Description:
Langerhans cell histiocytosis (LCH) and Erdheim-Chester disease (ECD) are clinically heterogenous histiocytic neoplasms whose underlying etiology has long been unknown. Genomic analysis revealed the presence of somatic activating mutations of BRAFV600E in 50% of LCH and ECD patients, as well as mutations in MAP2K1 in 25% of BRAF-wild type LCH patients.
Dr. Donald Parsons will review the recent advances in understanding the molecular mechanisms of LCH and non-LCH histiocytic neoplasms. He will discuss the role of recurrent somatic activating MAPK pathway mutations in patients with LCH, ECD and JXG. He will propose re-definition of these disorders as myeloid neoplastic disorders driven by MAPK activation at critical stages of myelopoiesis.
Dr. Sheila Weitzman will give a clinical overview on LCH and discuss the rationale for current treatment strategies. She will discuss the possible correlation between BRAF/ARAF/MAP2K1 mutations and patient outcomes, and will review the potential benefit of treating resistant high-risk LCH cases with BRAFV600E inhibitors and the possible future role of RAF/MEK inhibitors.
Dr. Julien Haroche will discuss the clinical and diagnostic approach to ECD patients including the newly proposed ECD classification. He will review the various treatment options with Interferon-α, anticytokine-directed therapy, chemotherapy and targeted therapy in ECD with BRAF inhibitors. He will also give a clinical and treatment review on other uncommon histiocytic disorders such as Rosai-Dorfman disease (RDD) and Juvenile Xanthogranuloma (JXG) that are more commonly diagnosed in young patients.