Juratli Hazem A, Wassmer Hanna, Juskevicius Darius, Alborelli Ilaria, Hartmann Karin, Tzankov Alexandar
Pathology, Institute of Medical Genetics and Pathology, University Hospital Basel and University of Basel, Basel, Switzerland.
Histological Diagnostics, Kempf and Pfaltz, Zurich, Switzerland.
Virchows Arch. 2025 Sep 2. doi: 10.1007/s00428-025-04237-9.
Mast cell (MC) disorders result from inappropriate release of mediators and/or excessive accumulation of MCs, leading to symptoms of various organs and systems. Clonal MC disorders are defined by the presence of phenotypically aberrant and/or KIT-mutated MCs, and if aggregates of MCs are detectable, are designated as mastocytosis. Systemic mastocytosis (SM) affects mainly the bone marrow, with or without skin involvement. It is associated with the activating mutation D816V in the KIT gene. Other activating KIT gene variants are also observable in SM; activating KIT mutations are recognized as a minor diagnostic SM-criterion. We report a novel KIT variant in a patient with indolent SM, an in-frame deletion-insertion affecting amino acids D816 to N819 (D816_N819delinsll), creating an aliphatic pouch similar to that resulting from the D816V mutation, and leading to MC activation as suggested by the symptoms of the patient and the positivity for phosphorylated STAT5 in the clonal MCs.
肥大细胞（MC）疾病是由介质的不适当释放和/或MC的过度积聚引起的，导致各个器官和系统出现症状。克隆性MC疾病的定义是存在表型异常和/或KIT突变的MC，如果可检测到MC聚集，则称为肥大细胞增多症。系统性肥大细胞增多症（SM）主要影响骨髓，可伴有或不伴有皮肤受累。它与KIT基因中的激活突变D816V有关。其他激活的KIT基因变体在SM中也可观察到；激活的KIT突变被认为是SM的次要诊断标准。我们报告了一例惰性SM患者中的一种新型KIT变体，这是一种影响氨基酸D816至N819的框内缺失插入（D816_N819delinsll），产生了一个类似于D816V突变产生的脂肪袋，并根据患者的症状和克隆性MC中磷酸化STAT5的阳性结果提示导致MC激活。
