Department of Pediatrics, The University of Calgary, and The Alberta Children's Hospital, #200, 233, 16th Avenue NW, Calgary, AB, T2M 0H5, Canada.
Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada.
World J Pediatr. 2019 Dec;15(6):536-545. doi: 10.1007/s12519-019-00304-9. Epub 2019 Aug 28.
Langerhans cell histiocytosis (LCH) is a group of diseases characterized by the proliferation and accumulation of Langerhans cells. Clinical presentations of LCH vary widely.
A PubMed search was conducted using Clinical Queries with the key term "Langerhans cell histiocytosis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. This paper is based on, but not limited to, the search results.
Generally, patients with LCH can be divided into two groups based on the extent of involvement at diagnosis, namely, single-system LCH and multisystem LCH. The involvement may be unifocal or multifocal. Patients with isolated bone lesions typically present between 5 and 15 years of age, whereas those with multisystem LCH tend to present before 5 years of age. The clinical spectrum is broad, ranging from an asymptomatic isolated skin or bone lesion to a life-threatening multisystem condition. Clinical manifestations include, among others, "punched out" lytic bone lesion, seborrheic dermatitis-like eruption, erythematous/reddish-brown crusted/scaly papules/maculopapules/plaques/patches, and eczematous lesions, diabetes insipidus, hepatosplenomegaly, cytopenias, lymphadenopathy, and an acute fulminant disseminated multisystem condition presenting with fever, skin rash, anemia, thrombocytopenia, lymphadenopathy, and hepatosplenomegaly. The diagnosis is clinicopathologic, based on typical clinical findings and histologic/immunohistochemical examination of a biopsy of lesional tissue. Positive CD1a, S100, and/or CD207 (Langerin) immunohistochemical staining of lesional cells is required for a definitive diagnosis. Watchful waiting is recommended for patients with skin-only LCH. Patients with symptomatic or refractory skin-only LCH may be treated with topical tacrolimus/corticosteroids, topical nitrogen mustard, oral methotrexate, or oral hydroxyurea. The current recommended first-line therapy for patients with multisystem LCH is 12 months therapy with prednisone and vinblastine. Mercaptopurine is added for patients with risk organ involvements.
Because of the broad spectrum of clinical manifestations and the extreme diversity of disease, LCH remains a diagnostic dilemma. Morphological identification of LCH cells and positive immunochemical staining with CD1a, S100, and/or CD207 (Langerin) of lesional cells are necessary for a definitive diagnosis.
朗格汉斯细胞组织细胞增生症（LCH）是一组以朗格汉斯细胞增殖和积聚为特征的疾病。LCH 的临床表现差异很大。
使用临床查询中的关键词“朗格汉斯细胞组织细胞增生症”在 PubMed 上进行了搜索。搜索策略包括荟萃分析、随机对照试验、临床试验、观察性研究和综述。本文基于但不限于搜索结果。
一般来说，根据诊断时受累范围，LCH 患者可分为单系统 LCH 和多系统 LCH 两组。受累可能是局灶性或多灶性的。孤立性骨病变的患者通常在 5 至 15 岁之间出现，而多系统 LCH 的患者则倾向于 5 岁之前出现。临床表现广泛，从无症状的孤立性皮肤或骨病变到危及生命的多系统疾病。临床表现包括“凿孔样”溶骨性病变、脂溢性皮炎样皮疹、红斑/红棕色结痂/鳞屑丘疹/斑丘疹/斑块和湿疹样病变、尿崩症、肝脾肿大、细胞减少症、淋巴结病和急性暴发性播散性多系统疾病，表现为发热、皮疹、贫血、血小板减少症、淋巴结病和肝脾肿大。诊断是临床病理的，基于典型的临床发现和病变组织的组织学/免疫组织化学检查。病变细胞的 CD1a、S100 和/或 CD207（朗格汉斯）免疫组织化学染色阳性是明确诊断所必需的。对于仅皮肤受累的 LCH 患者，建议观察等待。对于有症状或难治性仅皮肤 LCH 的患者，可给予局部他克莫司/皮质类固醇、局部氮芥、口服甲氨蝶呤或口服羟基脲治疗。多系统 LCH 患者的一线治疗推荐是泼尼松和长春新碱治疗 12 个月。对于有风险器官受累的患者，加入巯基嘌呤。
由于临床表现广泛，疾病多样性极大，LCH 仍然是一个诊断难题。病变细胞的形态学识别和 CD1a、S100 和/或 CD207（朗格汉斯）的免疫化学染色阳性是明确诊断所必需的。
