Weeden Amy L, Taylor Kyle R, Terrell Scott P, Gallagher Alexander E, Wamsley Heather L
Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
Vet Clin Pathol. 2016 Dec;45(4):584-593. doi: 10.1111/vcp.12426. Epub 2016 Nov 21.
A 10-year-old castrated Domestic Short-Haired cat was presented to a primary care veterinarian for a wellness examination and laboratory examination for monitoring of diabetes mellitus. The CBC revealed marked thrombocytosis, leukopenia and macrocytic, normochromic anemia. The cat tested negative for FeLV and feline immunodeficiency virus, but was positive for Mycoplasma haemominutum by PCR. Hematologic abnormalities were not responsive to therapy, so a repeat CBC and a bone marrow aspiration for cytology were performed. Additional blood smear findings included anisocytosis with megaloblastic erythroid precursors, large platelets, eosinophilic myelocytes and metamyelocytes, and rare unidentified blasts. The bone marrow smear was highly cellular, and the cytologic pattern was consistent with myelodysplastic syndrome with an erythroid predominance. At that time, 15% blasts were present. The cat was treated with a vitamin K analog, doxycycline, and prednisolone, but without a clinical response. Within 3 months, euthanasia was elected due to declining quality of life, and a necropsy was performed. Postmortem bone marrow smears were highly cellular and dominated by monomorphic blasts of unknown line of origin (52%), persistent marked erythroid and megakaryocytic dysplasia, and ineffective erythropoiesis and granulopoiesis. Immunohistochemical, immunocytochemical, and cytochemical stains resulted in a diagnosis of acute myeloid leukemia of unclassified type. Additional histologic findings included mixed hepatitis with trematode infestation and lymphoplasmacytic interstitial nephritis with fibrosis. The marked thrombocytosis with myelodysplastic syndrome and the FeLV-negative status of this cat were unusual. The difficulty in classifying the myelodysplasia and subsequent leukemia highlights a need for further reporting and characterization of these types of disease.
一只10岁去势的家养短毛猫被送到一位初级保健兽医处进行健康检查和实验室检查，以监测糖尿病。血常规显示明显的血小板增多、白细胞减少以及大细胞正色素性贫血。这只猫的猫白血病病毒和猫免疫缺陷病毒检测呈阴性，但通过聚合酶链反应检测发现感染了溶血支原体。血液学异常对治疗无反应，因此再次进行了血常规检查和骨髓穿刺细胞学检查。额外的血涂片检查结果包括红细胞大小不均伴有巨幼红细胞前体、大血小板、嗜酸性晚幼粒细胞和杆状核粒细胞，以及罕见的未识别的原始细胞。骨髓涂片细胞高度丰富，细胞学模式与以红系为主的骨髓增生异常综合征一致。当时，原始细胞占15%。这只猫接受了维生素K类似物、强力霉素和泼尼松龙治疗，但无临床反应。3个月内，由于生活质量下降选择了安乐死，并进行了尸检。死后骨髓涂片细胞高度丰富，以来源不明的单形性原始细胞为主（52%），持续存在明显的红系和巨核系发育异常，以及无效的红细胞生成和粒细胞生成。免疫组织化学、免疫细胞化学和细胞化学染色结果诊断为未分类的急性髓系白血病。其他组织学发现包括伴有吸虫感染的混合性肝炎和伴有纤维化的淋巴浆细胞性间质性肾炎。这只猫出现明显的血小板增多伴骨髓增生异常综合征且猫白血病病毒呈阴性的情况并不常见。骨髓增生异常及后续白血病的分类困难凸显了对这类疾病进行进一步报告和特征描述的必要性。
