Pan Zenggang, Kleinschmidt-DeMasters Bette K
Department of Pathology; Department of Neurology; and Department of Neurosurgery, University of Colorado Denver, Aurora, Colorado.
J Neuropathol Exp Neurol. 2017 Dec 1;76(12):986-996. doi: 10.1093/jnen/nlx095.
Erdheim-Chester disease (ECD) is a rare nonLangerhans cell histiocytosis. Although approximately 50% of cases eventually involve the central nervous system (CNS), the CNS has seldom been reported as the initial biopsy site. The diagnosis of CNS ECD can be challenging due to morphologic overlap with reactive histiocytic proliferation, Langerhans cell histiocytosis (LCH), and extranodal Rosai-Dorfman disease (RDD). We present 3 cases from our files that illustrate the protean manifestations of ECD. Case 1 was a 47-year-old man with ataxia, dysarthria, and intermittent ophthalmoplegia whose cerebellar biopsy had shown only profuse, nonspecific Rosenthal fiber-rich piloid gliosis; ECD was diagnosed only at autopsy. The gliosis and marked variations in histiocyte morphology in different anatomical sites added to the diagnostic challenge. Case 2 was a 67-year-old female with chronic progressive symptoms and a pontine lesion that had been considered to be CLIPPERS by neuroimaging. Identification of a BRAFV600E mutation allowed an ECD diagnosis and treatment with the specific BRAFV600E inhibitor vemurafenib, which resulted in a marked sustained clinical response. Case 3 was diagnosed as ECD after positive bone biopsy with typical foamy histiocytes. Six years later, there was massive dural involvement that showed RDD-like, BRAF-mutation-negative histiocytosis. These cases highlight the clinical and histologic overlap that can occur among these disorders.
厄尔德海姆-切斯特病（ECD）是一种罕见的非朗格汉斯细胞组织细胞增多症。尽管约50%的病例最终会累及中枢神经系统（CNS），但中枢神经系统很少被报道为初始活检部位。由于与反应性组织细胞增生、朗格汉斯细胞组织细胞增多症（LCH）和结外罗萨伊-多夫曼病（RDD）在形态学上存在重叠，中枢神经系统ECD的诊断可能具有挑战性。我们展示了来自我们病例档案中的3个病例，以说明ECD的多种表现形式。病例1是一名47岁男性，患有共济失调、构音障碍和间歇性眼肌麻痹，其小脑活检仅显示大量、非特异性的富含罗森塔尔纤维的束状胶质增生；仅在尸检时才诊断为ECD。不同解剖部位的胶质增生和组织细胞形态的显著差异增加了诊断难度。病例2是一名67岁女性，有慢性进行性症状，桥脑有一个病变，神经影像学检查曾认为是CLIPPERS。BRAFV600E突变的鉴定使得能够诊断为ECD，并使用特异性BRAFV600E抑制剂维莫非尼进行治疗，从而产生了显著的持续临床反应。病例3在骨活检发现典型的泡沫状组织细胞后被诊断为ECD。6年后，出现大量硬脑膜受累，表现为类似RDD的、BRAF突变阴性的组织细胞增多症。这些病例突出了这些疾病之间可能出现的临床和组织学重叠。
