Mastocytosis is a heterogeneous group of neoplasms defined by a numerical increase and accumulation of clonal mast cells (MCs) in various organ systems. The disease may present as cutaneous mastocytosis or systemic mastocytosis (SM). On the basis of histopathological and molecular features, clinical variables, and organ involvement, SM is divided into indolent SM, smoldering SM, SM with an associated hematologic neoplasm, aggressive SM, and MC leukemia. Each variant is defined by unique diagnostic criteria and a unique spectrum of clinical presentations. A key driver of MC expansion and disease evolution is the oncogenic machinery triggered by mutant forms of KIT. The genetic background, additional somatic mutations, and comorbidities also contribute to the course and prognosis. Patients with SM may also suffer from mediator-related symptoms or even an MC activation syndrome. This article provides an update of concepts on the genetics, etiology, and pathology of mastocytosis, with emphasis on diagnostic criteria and new treatment concepts.

中文翻译：

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对肥大细胞增多症发病机制的新见解：诊断和治疗中的新兴概念


肥大细胞增多症是一组异质性肿瘤，其定义为各个器官系统中克隆性肥大细胞（MC）的数量增加和积累。该疾病可能表现为皮肤肥大细胞增多症或系统性肥大细胞增多症（SM）。根据组织病理学和分子特征、临床变量和器官受累，SM 分为惰性 SM、冒烟性 SM、伴相关血液肿瘤的 SM、侵袭性 SM 和 MC 白血病。每种变异都由独特的诊断标准和独特的临床表现来定义。 MC 扩张和疾病进化的一个关键驱动因素是 KIT 突变形式引发的致癌机制。遗传背景、额外的体细胞突变和合并症也对病程和预后有影响。 SM 患者还可能出现介质相关症状，甚至出现 MC 激活综合征。本文提供了肥大细胞增多症遗传学、病因学和病理学概念的更新，重点是诊断标准和新的治疗概念。