朗格汉斯细胞组织细胞增生症

Langerhans cell histiocytosis is an inflammatory myeloid neoplasm characterised by activating mutations of the mitogen-activated protein kinase pathway. There is clonal proliferation of pathogenic Langerhans cells in single or multiple organs.

临床表现异质性大，可以表现为自愈性骨病，也可以累及多系统甚至危及生命。

有相应临床表现时，病变细胞组织活检显示 CD1a 和Langerhans 蛋白 (CD207) 阳性即可确诊。

Single-system disease may resolve without treatment and require careful monitoring only.

Single-system disease involving risk organs and multi-system disease is treated with systemic chemotherapy.

Adverse prognostic factors include poor response to therapy and risk-organ involvement.

Langerhans cell histiocytosis (LCH) is a rare disease characterised by the clonal proliferation of pathogenic Langerhans cells, leading to inflammation and tissue destruction.[1]Emile JF, Abla O, Fraitag S, et al. Revised classification of histiocytoses and neoplasms of the macrophage-dendritic cell lineages. Blood. 2016 Jun 2;127(22):2672-81. https://ashpublications.org/blood/article/127/22/2672/35156/Revised-classification-of-histiocytoses-and http://www.ncbi.nlm.nih.gov/pubmed/26966089?tool=bestpractice.com

LCH primarily affects children. The most commonly involved organs in children are the bone, skin, pituitary gland, liver, spleen, haematopoietic system, lungs, lymph nodes, and central nervous system.[2]Haupt R, Minkov M, Astigarraga I, et al; Euro Histio Network. Langerhans cell histiocytosis (LCH): guidelines for diagnosis, clinical work-up, and treatment for patients till the age of 18 years. Pediatr Blood Cancer. 2013 Feb;60(2):175-84. https://onlinelibrary.wiley.com/doi/10.1002/pbc.24367 http://www.ncbi.nlm.nih.gov/pubmed/23109216?tool=bestpractice.com

LCH was previously called histiocytosis X.[3]Allen CE, Merad M, McClain KL. Langerhans-cell histiocytosis. N Engl J Med. 2018 Aug 30;379(9):856-68. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6334777 http://www.ncbi.nlm.nih.gov/pubmed/30157397?tool=bestpractice.com