Department of Pathology, Peking University First Hospital, Beijing 100034, China.
Laboratory of Electron Microscopy, Peking University First Hospital, Beijing 100034, China.
Eur J Dermatol. 2020 Feb 1;30(1):32-40. doi: 10.1684/ejd.2019.3679.
Non-Langerhans cell histiocytosis (non-LCH) is a collective term that encompasses a long list of rare "histiocytosis" that do not meet the criteria for Langerhans cell histiocytosis (LCH). Among cutaneous non-LCH, the xanthogranuloma (XG) family represents a distinct group of disorders derived from dermal dendritic cells (DDCs) at different stages of differentiation.
To investigate the clinicopathological characteristics of the XG family in adults and review the relevant literature.
We performed a retrospective clinicopathological study of five adult cases with a previous diagnosis of non-LCH. Clinicopathological features, immunophenotypes, genetic alterations and ultrastructural characteristics were analysed.
Skin biopsies revealed that all five cases were characterized by diffuse infiltration of polymorphic cells, which were immunoreactive to factor XIIIa but negative for Langerin, CD1a, and S100. None of the cases harboured the BRAF V600E mutation. Electron microscopy of two cases exhibited abundant cytoplasmic processes with numerous lysosome-like dense bodies and electron-lucent vesicles in the cytoplasm and extracellular matrix. The overall features suggested that DDCs are the cellular origin, and these cases fulfilled the criteria for the XG family.
The XG family represents a spectrum of rare diseases with different clinical presentations, a wide range of morphological appearances, and a shared common origin (DDCs). This group of disorders has been proposed as a unique entity with diagnostic challenges that should not be underestimated.
非朗格汉斯细胞组织细胞增生症（non-LCH）是一个涵盖了一系列罕见的“组织细胞增生症”的术语，这些疾病不符合朗格汉斯细胞组织细胞增生症（LCH）的标准。在皮肤非朗格汉斯细胞组织细胞增生症中，黄色肉芽肿（XG）家族代表了一组源自不同分化阶段真皮树突状细胞（DDC）的独特疾病。
探讨成人 XG 家族的临床病理特征，并复习相关文献。
我们对 5 例先前诊断为非朗格汉斯细胞组织细胞增生症的成人病例进行了回顾性临床病理研究。分析了临床病理特征、免疫表型、遗传改变和超微结构特征。
皮肤活检显示，所有 5 例均表现为弥漫性多形性细胞浸润，这些细胞对因子 XIIIa 呈免疫反应性，但对朗格汉斯细胞、CD1a 和 S100 呈阴性。这些病例均未发现 BRAF V600E 突变。2 例电镜显示，细胞质内有丰富的细胞质突起，细胞质和细胞外基质内有大量溶酶体样致密体和电子透明小泡。总体特征提示 DDC 是这些病例的细胞起源，符合 XG 家族的标准。
XG 家族代表了一组具有不同临床表现、广泛形态表现和共同起源（DDC）的罕见疾病。该组疾病被认为是一种具有诊断挑战的独特实体，不应低估。
