Takai Kazue, Ushiki Takashi, Nikkuni Koji, Hashidate Hideki, Shibuya Hiroyuki
Division of Hematology, Niigata City General Hospital.
Rinsho Ketsueki. 2011 Feb;52(2):73-7.
A 52-year-old woman presented with isolated thrombocytosis in 2003. After 5 years of observation under a tentative diagnosis of essential thrombocythemia (ET), she was referred to our hospital because of anemia and leukopenia. Bone marrow biopsy demonstrated increases of megakaryocytes and myelofibrosis, but splenomegaly was absent. A karyotype study of bone marrow detected t(9;22) (q34;q11.2) in 6 of the 20 metaphases studied. Peripheral blood neutrophil BCA-ABL fusion signals (FISH) were not detected. Because RT-PCR assay of bone marrow detected major-BCR-ABL mRNA (b3a2), treatment with imatinib (400 mg/day) was started. After transient thrombocytopenia, normalization of blood cell counts and improvement of myelofibrosis were achieved. JAK2 V617F mutation and M-BCR-ABL mRNA was negative in peripheral blood. Clinical and laboratory data suggest that this case represents a rare and atypical myeloproliferative neoplasm with BCR-ABL translocation restricted mainly to the megakaryocyte lineage.
一名52岁女性于2003年出现单纯性血小板增多症。在初步诊断为原发性血小板增多症（ET）并观察5年后，因贫血和白细胞减少转诊至我院。骨髓活检显示巨核细胞增多和骨髓纤维化，但无脾肿大。对20个中期细胞进行的骨髓核型研究发现，其中6个存在t(9;22) (q34;q11.2)。未检测到外周血中性粒细胞BCA-ABL融合信号（FISH）。由于骨髓的RT-PCR检测发现主要BCR-ABL mRNA（b3a2），开始使用伊马替尼（400mg/天）治疗。经过短暂的血小板减少后，血细胞计数恢复正常，骨髓纤维化得到改善。外周血JAK2 V617F突变和M-BCR-ABL mRNA均为阴性。临床和实验室数据表明，该病例代表一种罕见的非典型骨髓增殖性肿瘤，BCR-ABL易位主要局限于巨核细胞系。
