Mansor N A, Yusof N, Tang Y L, Ithnin A, Azma R Z, Tumian N R, Shuib S
Universiti Kebangsaan Malaysia Medical Centre, Faculty of Medicine, Department of Pathology, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia.
Malays J Pathol. 2018 Aug;40(2):191-197.
Essential thrombocythaemia (ET) is a chronic myeloproliferative neoplasm (MPN) characterised by persistent thombocytosis. It is an indolent disorder but transformation to myelofibrosis (MF), acute myeloid leukaemia (AML) or myelodyplastic syndrome (MDS) has been reported.
We described a patient with ET whose disease evolved into MDS with fibrosis and complex karyotype after 15 years of stable disease. She was asymptomatic and was on hydroxyurea (HU) treatment until recently when she presented with worsening anaemia. Physical examination showed mild splenomegaly. Full blood picture showed leukoerythroblastic picture with presence of 3% circulating blasts and background of dysplastic features such as hypogranular cytoplasm and nuclear hyposegmentation of neutrophils. The bone marrow aspiration was haemodiluted but revealed presence of 6% blast cells, trilineage dysplasia and predominant erythroid precursors (60%). Trephine biopsy showed no excess of blast cells and normal quantity of erythroid precursors, but there was increased in fibrosis (WHO grade 2) and presence of dysmegakaryopoeisis such as nuclear hypolobation, multinucleation and micromegakaryocytes. Cytogenetic study showed complex karyotype; monosomy of chromosome 2, chromosome 5, chromosome 18 and presence of a marker chromosome (42~44, XX,-2,-5,-18,+mar). Fluorescence in situ hybridisation (FISH) showed 5q deletion (CSF1R and EGR1).
The findings were consistent with transformation of ET to MDS with fibrosis and complex karyotype. ET progression to MDS is considered rare. The presence of complex karyotype and fibrosis in MDS are associated with unfavourable outcome.
原发性血小板增多症（ET）是一种慢性骨髓增殖性肿瘤（MPN），其特征为持续性血小板增多。它是一种惰性疾病，但已有报道称其可转化为骨髓纤维化（MF）、急性髓系白血病（AML）或骨髓增生异常综合征（MDS）。
我们描述了一名ET患者，其病情在稳定15年后演变为伴有纤维化和复杂核型的MDS。她无症状，一直接受羟基脲（HU）治疗，直到最近出现贫血加重。体格检查显示轻度脾肿大。全血细胞图像显示为幼粒-幼红细胞血象，有3%的循环原始细胞，并有发育异常特征，如中性粒细胞胞质颗粒减少和核分叶过少。骨髓穿刺液被稀释，但显示有6%的原始细胞、三系发育异常以及主要为红系前体细胞（60%）。骨髓活检显示原始细胞不过多，红系前体细胞数量正常，但纤维化增加（世界卫生组织2级），并存在巨核细胞生成异常，如核分叶减少、多核和微巨核细胞。细胞遗传学研究显示为复杂核型；2号、5号、18号染色体单体以及一条标记染色体（42~44，XX，-2，-5，-18，+mar）。荧光原位杂交（FISH）显示5q缺失（CSF1R和EGR1）。
这些发现与ET转化为伴有纤维化和复杂核型的MDS一致。ET进展为MDS被认为是罕见的。MDS中复杂核型和纤维化的存在与不良预后相关。
