Marino Christina L, Tran Jimmy N S N, Stokol Tracy
Department of Clinical Studies, College of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA (Marino).
Departments of Biomedical Sciences (Tran), College of Veterinary Medicine, Cornell University, Ithaca, NY.
J Vet Diagn Invest. 2017 May;29(3):338-345. doi: 10.1177/1040638716689581. Epub 2017 Feb 16.
A 4-y-old neutered male German Shepherd Dog was presented with a 3-d duration of lethargy, restlessness, and vomiting. Physical examination revealed generalized lymphadenopathy, pale mucous membranes, systolic heart murmur, dehydration, and fever. Hematologic abnormalities included moderate-to-marked leukocytosis, characterized by neutrophilia with a left shift to progranulocytes and 2% presumptive myeloid blasts, marked anemia that was nonregenerative, and marked thrombocytopenia. Dysplasia was evident in neutrophils and platelets. Bone marrow examination revealed marked myeloid and megakaryocytic hyperplasia with 7% blasts, erythroid hypoplasia, and trilineage dysplasia. Flow cytometric analysis confirmed that bone marrow cells were mostly of neutrophil lineage, with reduced expression of common leukocyte antigens (CD45, CD18) and neutrophil-specific antigen. Bone marrow cells were cytogenetically analyzed for the breakpoint cluster region-Abelson oncogene using multicolor fluorescent in situ hybridization. The genetic aberration was present in 7% of cells, which was a negative result (>10% of cells is considered positive). Euthanasia was elected. Histologic examination showed extensive infiltration of multiple organs by neoplastic myeloid cells, with effacement of lymph node and splenic architecture. The final diagnosis was atypical chronic myeloid leukemia (aCML), an uncommon myeloproliferative disorder with features of myelodysplastic syndromes (dysplasia) and chronic leukemia (neutrophilic leukocytosis with <20% marrow blasts, extramedullary infiltrates). The trilineage dysplasia, lack of monocytosis, and supporting cytogenetics distinguish aCML from CML, chronic neutrophilic leukemia, and chronic myelomonocytic leukemia.
一只4岁已绝育的雄性德国牧羊犬出现了持续3天的嗜睡、烦躁不安和呕吐症状。体格检查发现全身淋巴结病、黏膜苍白、收缩期心脏杂音、脱水和发热。血液学异常包括中度至重度白细胞增多，其特征为中性粒细胞增多并伴有核左移至早幼粒细胞，以及2%的疑似髓系原始细胞，显著的非再生性贫血和显著的血小板减少。中性粒细胞和血小板可见发育异常。骨髓检查显示显著的髓系和巨核细胞增生，有7%的原始细胞，红系发育不全和三系发育异常。流式细胞术分析证实骨髓细胞大多为中性粒细胞系，常见白细胞抗原（CD45、CD18）和中性粒细胞特异性抗原表达降低。使用多色荧光原位杂交对骨髓细胞进行细胞遗传学分析，检测断裂点簇集区-阿贝尔森癌基因。7%的细胞存在基因畸变，此为阴性结果（>10%的细胞被认为是阳性）。决定实施安乐死。组织学检查显示肿瘤性髓系细胞广泛浸润多个器官，淋巴结和脾脏结构消失。最终诊断为非典型慢性髓系白血病（aCML），这是一种罕见的骨髓增殖性疾病，具有骨髓增生异常综合征（发育异常）和慢性白血病（中性粒细胞增多伴骨髓原始细胞<20%，髓外浸润）的特征。三系发育异常、无单核细胞增多以及支持性的细胞遗传学检查将aCML与慢性髓系白血病、慢性中性粒细胞白血病和慢性粒单核细胞白血病区分开来。
