title: Langerhans Cell Histiocytosis: A Clinicopathologic Review and Molecular Pathogenetic Update.
abstract: Langerhans cell histiocytosis (LCH) comprises a wide spectrum of clinical disorders that have in common a proliferation of Langerhans-type cells with characteristic morphologic, immunophenotypic, and ultrastructural features. In part because of the diverse clinical manifestations of LCH, there has long been controversy over whether LCH is best considered a reactive process or a neoplasm. Herein, we discuss the clinical and pathologic features of LCH, including recent advances in the understanding of the molecular pathogenesis of this disease that support its categorization as a neoplasm. We also review the implications that these recently described molecular characteristics may have on risk stratification and treatment of LCH.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Harmon
authors.affiliation: From the Department of Pathology, University of Michigan Hospital and Health Systems, Ann Arbor.
authors.forename: Noah
authors.initials: N
authors.lastname: Brown
mesh_terms: D018949:Antigens, CD1 / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D003937:Diagnosis, Differential; D006646:Histiocytosis, Langerhans-Cell / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007801:Langerhans Cells / Q000378:metabolism / Q000473:pathology*; D048369:MAP Kinase Kinase 1 / Q000235:genetics; D009154:Mutation; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D009418:S100 Proteins / Q000378:metabolism
chemical_list: D018949:Antigens, CD1; D014408:Biomarkers, Tumor; C419393:CD1a antigen; D009418:S100 Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D048369:MAP Kinase Kinase 1