背景:伴有血小板源性生长因子受体β(PDGFRB)重排的髓系肿瘤通常在外周血和骨髓中出现嗜酸性粒细胞增多。在这里,我们报告了一例系统性肥大细胞增多症相关的骨髓样肿瘤,伴有嗜碱性粒细胞和PRKG2-PDGFRB融合基因。
方法:一名53岁男性患者在2年时间内出现血小板增多和血红蛋白正常的疲乏感。考虑到原发性血小板增多症的可能性,患者接受了羟基脲和干扰素治疗.然后由于不良事件和病情恶化而停止治疗。
方法:通过骨髓形态学和流式细胞术证实急性髓细胞白血病(AML)的诊断。荧光原位杂交(FISH)检测PDGFRB重排,染色体核型46,XY,t(4:5)(q21:q33)。通过下一代测序(NGS)观察到PRKG2-PDGFRB融合,并通过RT-PCR和随后的Sanger测序进行验证。骨髓穿刺的结果,骨髓活检,免疫表型显示系统性肥大细胞增多相关髓样肿瘤伴嗜碱性粒细胞增多症。
方法:入院当天给予伊马替尼400mg/d。给予阿扎胞苷75mg/m2诱导治疗10天,随后进行一个疗程的DHAG巩固治疗。伊马替尼连续口服。
结果:在治疗的第8天,患者的饮食和疲劳改善。在第25天实现血液学和骨髓形态学缓解。3个月后细胞遗传学完全缓解,并持续存在(2020年12月20日)。PRKG2-PDGFRB融合基因在诊断后7个月转阴。
结论:外周血和/或骨髓中嗜碱性粒细胞和/或肥大细胞增多的患者应筛查PDGFRB异常和骨髓或淋巴肿瘤。患有PDGFRB异常的患者对伊马替尼具有良好的反应。
BACKGROUND: Myeloid neoplasms with platelet-derived growth factor receptor β (PDGFRB) rearrangement usually present with eosinophilia in the peripheral blood and bone marrow. Here we report a
case of systemic mastocytosis related myeloid neoplasms with basophilia and PRKG2-PDGFRB fusion gene.
METHODS: A 53-year-old male patient felt fatigue with thrombocythemia and normal hemoglobin over 2 years. Considering the possibility of primary thrombocytosis, the patient was treated with hydroxyurea and interferon. Then the therapy was stopped due to adverse events and worsen condition.
METHODS: Acute myelogenous leukemia (AML) diagnosis was confirmed by bone marrow morphology and flow cytometry. PDGFRB rearrangement was detected by fluorescence in situ hybridization (FISH) test, with chromosome karyotype 46,XY,t(4:5)(q21:q33). PRKG2-PDGFRB fusion was observed by next generation sequencing (NGS) and verified by RT-PCR followed by Sanger sequencing. The results of bone marrow aspiration, bone marrow biopsy, and immunophenotyping showed systemic mastocytosis-related myeloid tumor with basophilia.
METHODS: Imatinib 400 mg/d was given on the day of admission. Azacitidine 75 mg/m2 was given for induction therapy for 10 days, and followed by one course of DHAG consolidating therapy. Imatinib was taken orally continuously.
RESULTS: On the 8th day of treatment, the patient\'s diet and fatigue improved. The hematological and bone marrow morphological remission was achieved on the 25th day. Cytogenetic complete remission was achieved 3 months later and continued to present (December 20, 2020). PRKG2-PDGFRB fusion gene turned negative 7 months later from diagnosis.
CONCLUSIONS: Patients with increased basophilic granulocyte and/or mast cells in peripheral blood and/or bone marrow should be screened for PDGFRB abnormality and myeloid or lymphatic tumor. Patients bearing PDGFRB abnormality have a good response to imatinib.