摘要目的：探讨Erdheim－Chester病（ ECD）患者的临床病理学特征、免疫表型、鉴别诊断及基因突变表现。方法收集3例ECD患者临床和病理资料，对其病变部位、组织形态、免疫表型（ EnVision法）和BRAF V600E基因突变情况进行回顾性分析，并复习文献和总结。结果3例中，男性2例，女性1例，因多发皮肤结节、骨痛就诊，影像学发现骨骼病变。光镜下可见梭形的纤维细胞，其间见大量富含脂质成分的组织细胞弥漫浸润，散在多核巨细胞，部分呈Touton型巨细胞改变，伴有少量散在淋巴细胞及浆细胞浸润；免疫组织化学显示所有梭形细胞、组织细胞及多核巨细胞均CD68（＋），CD1a（－），2例局灶弱表达S－100蛋白。基因突变检测显示2例BRAF V600E基因突变。结论 ECD是一种罕见的黄色肉芽肿性组织细胞增生症，其诊断主要依靠病理形态及免疫组织化学检测，但必须充分结合临床症状及影像学检查，目前还没有十分有效的治疗方法。

abstractsObjective To explore the clinicopathologic features, immunophenotype, differential diagnosis and gene mutation status of the Erdheim-Chester disease ( ECD ) .Methods Clinical and pathologic findings of 3 ECD cases were examined by gross, microscopic, immunohistochemical methods and BRAF V600E mutation.Related literatures were reviewed.Results Two male patients and one female patient presented clinically with multiple skin nodules, bone pain and bony lesions by imaging study.Microscopically, the lesions were composed of spindle-shaped fibroblasts, foamy histiocytes and scattered Touton-type giant cells embedded in reactive fibrous tissue.Lymphocytes, plasma cells, and multinucleated giant cells were also found.Immunohistochemically, all histiocytes were positive for CD68, none of which expressed CD1a, although 2 cases focally expressed weak S-100 stain.In 2 cases, BRAF V600E mutation was detected.Conclusions ECD is a rare disease of xanthogranulomatous histiocytosis.Its diagnosis relies on pathological and immunohistochemical findings, but correlation with clinical information, especially radiographic findings should be performed.No effective treatment of the disease is currently available.