Laboratory Assessment of Patients with Systemic Mastocytosis

小儿肥大细胞增多症的管理提出了一个挑战。临床和实验室结果以及骨髓评估的应用与医疗干预和预后相关，因此信息有限。儿童肥大细胞增多症的诊断标准主要基于成人研究。关于肥大细胞增多症儿童骨髓病理的资料很少。我们评估使用世界卫生组织（WHO）标准诊断全身性疾病的儿科患者。骨髓活检采用组织病理学、免疫组织化学、流式细胞术和KIT突变分析。50例进行了完整的骨髓评估。7名儿童接受了重复手术。我们在活检中发现了独特的临床组织病理学特征。骨髓活检显示轻度非典型的造血成熟，红细胞增多和细胞减少，这是一组患有荨麻疹、弥漫性皮肤肥大细胞增多症和惰性全身肥大细胞增多症的患者。色素性荨麻疹患者细胞增多最为明显。平均而言，弥漫性皮肤肥大细胞增多症或肥大细胞瘤患者的血液病升高最高。在这个队列中没有外周血细胞减少、骨髓增生异常综合征、骨髓增生性肿瘤或白血病的证据。该研究中患者的长期随访（中位6.9年，范围1-25年）显示，所有患者均保持临床稳定，未发展为更具侵袭性的变异。我们认为WHO标准适用于儿科全身性肥大细胞增多症的诊断。

The management of children with pediatric mastocytosis poses a challenge. There is a limited information as to the application of clinical and laboratory findings and bone marrow evaluation as they relate to medical intervention and prognosis. The diagnostic criteria for pediatric mastocytosis are largely based on adult studies. There is very little data about bone marrow pathology in children with mastocytosis. We evaluated the use of the World Health Organization (WHO) criteria for the diagnosis of systemic disease in pediatric patients. Bone marrow biopsies were analyzed by histopathology and immunohistochemistry, flow cytometry and KIT mutational analysis. Complete bone marrow evaluations were performed in 50 cases. Seven children had repeat procedures. We identified unique clinico-histopathological features within the biopsies. Bone marrow biopsies displayed mildly atypical hematopoietic maturation, increased hematogones and hypocellularity in a sub-set of patients with urticaria pigmentosa, diffuse cutaneous mastocytosis and indolent systemic mastocytosis. Hypocellularity was most pronounced in those with urticaria pigmentosa. Hematogone increases were highest, on average, in patients with diffuse cutaneous mastocytosis or mastocytomas. There was no evidence of peripheral blood cytopenias, myelodysplastic syndrome, myeloproliferative neoplasm or leukaemia within this cohort. Long-term follow-up of patients within this study (median 6.9 years; range 1-25 years) showed that all patients remained clinically stable without progression to a more aggressive variant. We conclude that the WHO criteria are applicable for the diagnosis of systemic mastocytosis in pediatrics.