Takai K, Sanada M, Shibuya H
Division of Hematology, Niigata City General Hospital.
Rinsho Ketsueki. 1992 Aug;33(8):1071-6.
A 63-year-old man was admitted because of anemia and thrombocytopenia. The bone marrow was hypercellular with 66.6% erythroblasts with dysplasia and 19.8% blasts. Cytogenetically, MAKA (major karyotypic aberrations) containing 5q-, -7, -17, with karyotypic instability was observed. A diagnosis of erythroleukemia (FAB M6) was made. Six months later, immature neutrophils increased in the peripheral blood, and blasts and promyelocytes increased to 25.8% and 20.0% of marrow cells, respectively. Three months later, blasts asts increased to 33.0% in the peripheral blood. They were ultrastructually positive for platelet peroxidase. Phenotypically, 69% and 63% of blasts were positive for CD41b (GPIIb/IIIa) and CD42a (GPIb), respectively. Bone marrow biopsy showed marked proliferation of blasts and dysplastic megakaryocytes accompanied by reticulin fibrosis. These findings suggested evolution to megakaryoblastic leukemia (FAB M7). In most cases, M6 defined by the FAB criteria is stem cell disorder with multilineage involvement and major erythroid component. M6-like features may be observed in the evolutive phase to acute leukemia from myelodysplastic syndrome (MDS).
一名63岁男性因贫血和血小板减少入院。骨髓细胞增生，有66.6%的发育异常的成红细胞和19.8%的原始细胞。细胞遗传学检查发现存在包含5号染色体长臂缺失、-7、-17的主要核型异常（MAKA），伴有核型不稳定。诊断为红白血病（FAB M6）。6个月后，外周血中未成熟中性粒细胞增多，原始细胞和早幼粒细胞分别增至骨髓细胞的25.8%和20.0%。3个月后，外周血中原始细胞增至33.0%。超微结构显示其血小板过氧化物酶呈阳性。表型上，69%和63%的原始细胞分别对CD41b（糖蛋白IIb/IIIa）和CD42a（糖蛋白Ib）呈阳性。骨髓活检显示原始细胞和发育异常的巨核细胞显著增殖，并伴有网状纤维增生。这些发现提示已演变为巨核细胞白血病（FAB M7）。在大多数情况下，FAB标准定义的M6是一种涉及多系的干细胞疾病，主要成分是红系。从骨髓增生异常综合征（MDS）演变为急性白血病的过程中可能会观察到M6样特征。
