Acute myelogenous leukemia with t(6;9)(p23;q34) and marrow basophilia: an overview

Acute myelogenous leukemia (AML) with chromosomal translocation (6;9)(p23;q34) is a rare disease with poor prognosis and distinct clinical and morphologic features. t(6;9) results in a chimeric fusion gene between DEK (6p23) and CAN/NUP214 (9q34). FLT3-ITD mutation is one of the most frequent mutations in AML and correlates with poor clinical outcome. Prevalence of FLT3-ITD is as high as 70% among patients with t(6;9) AML, and patients with t(6;9) AML and FLT3-ITD mutations usually have higher white blood cell counts, higher bone marrow blasts, and significantly lower rates of complete remission. t(6;9) is most commonly associated with AML-FAB-M2 and is considered by some researchers to be a separate disease entity because of its distinct clinical and morphologic features and poor prognostic implication. Distinct morphologic features of this entity include marrow basophilia and myelodysplasia, and immunophenotypically, the blast cells are positive for CD9, CD13, CD33, and HLA-DR; are usually positive for CD45 and CD38; and may be positive for CD15, CD34, and terminal deoxynucleotidyl transferase.     

Translocation (6;9)(p23;q34) in acute nonlymphocytic leukemia

A consistent chromosomal abnormality t(6;9)(p23;q34) was demonstrated in the bone marrow or unstimulated peripheral blood cultures of two patients with acute nonlymphocytic leukemia (ANLL). Only two additional cases with ANLL and a similar cytogenetic finding have been reported, indicating that this translocation may represent another chromosomal abnormality specifically associated with ANLL.     

六例伴t(6;9)(p23;q34)急性髓细胞白血病患者的临床和实验研究

目的 探讨伴t(6;9)(p23;q34)急性髓细胞白血病(acute myeloid leukemia,AML)患者的临床和生物学特点.方法 抽取骨髓细胞按常规制备染色体标本,采用R显带技术进行核型分析;采用标准流式细胞仪和一组单抗检测白血病细胞的抗原表达;应用6号与9号全染色体涂染探针进行染色体荧光原位杂交(fluorescence in situ hybridization,FISH)分析;应用逆转录-PCR技术进行DEK/CAN融合基因和FLT3-ITD突变的检测.结果 t(6;9)易位主要见于M2和M4(M2 4例,M4 2例).所有病例的原始细胞均高表达CD13、CD33,其中4例同时表达HLA-DR、3例同时表达CD34和CD117,1例同时表达CD38,1例同时表达CD15.涂染证实6例患者均涉及6和9号染色体的易位,逆转录-PCR检测显示6例患者的DEK/CAN融合基因均为阳性,其中3例同时存在FLT-ITD突变,6例中的3例经治疗后死亡,生存期分别为3、5和6个月,其余病例仍在缓解中.结论 t(6;9)(p23;q34)为AML少见的再现性异常,伴有t(6;9)(p23;q34)易位的AML具有独特的生物学特征和临床特点,预后大多不良.     

Loss of the Y chromosome associated with translocation t(6;9)(p23;q34) in a patient with acute nonlymphocytic leukemia

A 34-year-old male with acute nonlymphocytic leukemia (ANLL) and a t(6;9)(p23;q34) is described, in whom loss of the Y chromosome had occurred in the t(6;9) clone. The leukemic blasts were relatively undifferentiated and there was no increase in marrow basophils. The unusual clonal evolution and hematologic features in this patient are compared to 27 previously documented cases with this translocation.     

Translocation (6;9)(p23;q34) in smoldering leukemia and acute nonlymphocytic leukemia

Two further cases with myeloproliferative disorders (a child with smoldering leukemia and a young male with acute nonlymphocytic leukemia of FAB type M2) and a translocation t(6;9)(p23;q34) are described. Special attention is paid to environmental factors and the early age of onset of patients within the group of leukemias with this specific translocation. In one of our cases a secondary chromosomal anomaly has arisen, which is comparable with another case from the literature.     

Acute megakaryoblastic leukemia in an infant with a novel t(1;9)(p32;q34)

We report a case of a 14-month-old girl with acute megakaryoblastic leukemia (AMKL). May-Giemsa staining of the bone marrow cells revealed the proliferation of two distinct types of blasts. One type of blasts had cytoplasmic blebs, and the other showed a lymphoblastic morphology without blebs. Both types of blasts were negative for peroxidase and esterase reactions. Electron microscopic platelet peroxidase (PPO) reaction also revealed the presence of two types of blasts. One had irregular-shaped nuclei and positive PPO reaction in the nuclear envelope and rough endoplasmic reticulum but not in the Golgi apparatus. These types of blasts were considered to be megakaryoblasts. The other had an immature phenotype with round nuclei and positive PPO reaction in the nuclear envelope, rough endoplasmic reticulum, and the Golgi apparatus. The origin of this type of blasts could not be defined by their morphology. Surface marker analysis indicated that most of the leukemic cells expressed platelet markers, gpIIb, gpIIb/IIIa, gpIX, and gpIbalpha. Karyotypic analysis of the bone marrow cells of this unique subset of AMKL demonstrated a novel translocation, t(1;9)(p32;q34).     

Eosinophilic leukemia associated with t(2;5)(p23;q31)

Chromosomal aberrations have been reported in most malignant hematopoietic disorders such as acute or chronic myeloid leukemia, acute lymphoid leukemia, and myelodysplastic syndromes. Eosinophilic leukemia is a rare hematologic malignancy difficult to distinguish from other forms of idiopathic hypereosinophilic syndrome, so that the diagnosis is often made by exclusion, unless cytogenetic abnormalities can be demonstrated in bone marrow cells. We describe a patient with eosinophilic leukemia whose cytogenetic study shows a t(2;5)(p23;q31). Initial data could suggest a clonal eosinophilia, with an hepatosplenomegaly, severe pancytopenia, and a high level of blood and medullar eosinophilia.     

Translocation t(9;9)(p13;q34) in Philadelphia-negative chronic myeloid leukemia with breakpoint cluster region rearrangement

Chromosome analysis showed a t(9;9)(p13;q34) in a patient with chronic myeloid leukemia (CML) without a Philadelphia (Ph) chromosome in all examined cells. Southern blot analysis of leukocyte DNA revealed rearrangement of breakpoint cluster region (bcr) within the 5.8-kb bcr sequences as in Ph-positive CML patients. The findings confirm that the 9q34 and 22q11 bands are always involved in CML independent of the chromosomal evidence. It is suggested that Ph-negative bcr-positive CML may have variant translocations, as in the case of the t(9;9) reported here.     

Acute myeloblastic leukemia (AML) with t(6;9) (p23;q34): A specific subgroup of AML?

A case of acute myeloblastic leukemia (AML) of M2 type in the FAB classification without Auer bodies in the leukemic cells was shown to have t(6;9)(p23;q34) in the marrow cells. Four hematologically similar cases with identical karyotype changes have been published. We propose, in support of others, that this may constitute a subgroup of AML characterized by a translocation between chromosome #6 and #9.     

t(9;11)(p22;q23) translocation in blastic phase of chronic myeloid leukemia.

A patient with chronic myeloid leukemia showed clonal karyotypic evolution, with the appearance of an i(17q) and t(9;11)(p22;q23). This case sheds light upon leukemogenic events related to t(9;11)(p22;q23). The presence of t(9;22) and t(9;11) in the same clone showed that t(9;11) may affect a pluripotent stem cell, thus accounting for t(9;11) in both lymphoid and monocytic leukemias. In this patient, t(9;11) could not be related to a prior cytotoxic exposure and was instead the result of natural evolution of chronic myeloid leukemia. Furthermore, this led us to assume that the phenotype of blast cells may be determined by a chromosome abnormality. A phenotypic conversion from myeloblastic to undifferentiated morphologic aspect was observed when t(9;11) was detected, suggesting that t(9;11) may have induced a loss in differentiation of blast cells affected by this change. This assumption is in agreement with the putative presence of genes activated in pluripotent progenitors by 11q23 rearrangements.     

Translocation (6;9)(p23;q34) in acute nonlymphocytic leukemia: Three new cases

Several recent reports have described cases of acute nonlymphocytic leukemia with a unique chromosome translocation, t(6;9)(p23;q34). We have studied three additional patients who have acute nonlymphocytic leukemia and t(6;9)(p23;q34). Our findings provide additional support for the suggestion that this translocation is yet another distinct cytogenetic abnormality associated with myeloproliferative disorders.     

Simultaneous occurrence of t(9;22)(q34;q11.2) and t(16;16)(p13;q22) in a patient with chronic myeloid leukemia in blastic phase

Coexistence of two specific chromosomal translocations in the same clone is an infrequent phenomenon and has only rarely been reported in hematological malignancies. We report a combination of t(16;16)(p13;q22), the Philadelphia translocation t(9;22)(q34;q11.2), and deletion of the long arm of chromosome 7 in a patient with chronic myeloid leukemia in blast phase. Monotherapy treatment with imatinib mesylate resulted in the disappearance of the Ph-positive clone, but with persistence of t(16;16) and del(7) in all of the metaphases examined. The case illustrates that, although imatinib mesylate can be an effective treatment in eradication of the BCR–ABL fusion gene cells, the occurrence of additional specific abnormalities in Philadelphia-positive leukemias may pose a significant therapeutic challenge.     

Acute myeloid leukemia associated with hemophagocytic syndrome and t(4;7)(q21;q36)

Hemophagocytic syndrome (HS) is a histiocytic reactive process often associated with infections and/or malignancies. Clonal karyotypic abnormalities have been the hallmark of several hematological malignancies and have been shown to be of clinical significance in terms of both diagnosis and prognosis. While there are limited reports of both clonal and nonclonal abnormalities in HS, their clinical significance has not been established. Detection of such clonal abnormalities, as seen in some cases of HS, may indicate the presence of an occult malignant process, even when there is no microscopic evidence of a hematological malignancy. We report a case of HS in a child with clonal t(4;7)(q21;q36) which later progressed to acute myeloid leukemia (AML) with further clonal evolution. Our case strengthens the argument that cytogenetic studies in HS may be important in identifying the underlying occult malignant process.     

四例合并继发性der(9)t(9;22)(q34;q11)inv(9)(p22q34)异常的Ph阳性白血病的临床及分子遗传学研究

目的 探讨4例合并继发性der(9)t(9;22)(q34;q11)inv(9)(p22q34)异常的Ph阳性白血病的临床及分子遗传学特征.方法 应用骨髓细胞直接法或短期培养法制备染色体,经R显带进行核型分析.应用BCR/ABL双色双融合探针和9号染色体短臂及长臂涂染探针分别对4例伴有inv(9)(p22q34)的Ph阳性患者标本进行荧光原位杂交(fluorescence in situ hybridization,FISH)和染色体涂染分析.用逆转录PCR检测BCR/ABL融合基因转录本.结果 1例急性髓细胞白血病患者核型中有3种克隆,分别为正常细胞、t(9;22)(q34;q11)异常细胞、同时合并der(9)t(9;22)衍生克隆和Ph以及其它异常,即t(8;12)(q12;p11),der(9) t(9;22)inv(9) (p22q34),der(22)t(9;22)细胞.其余3例慢性粒细胞白血病患者均同时合并Ph和der(9)t(9;22)(q34;q11)inv(9)(p22q34).FISH结果显示,3例有1红1绿两个融合信号、2红2绿1个融合信号、且在中期分裂相中发现1红1绿荧光信号分别位于9号染色体的两端;另1例67.5％的细胞有2红1绿1融合信号,有1绿色信号的缺失即表明BCR基因的缺失.染色体涂抹检测发现4例患者均有9号染色体的倒位.逆转录PCR检测均为b3a2转录本.该继发异常既可发生于Ph阳性CML慢性期或急变期,也可发生于原发性Ph阳性AML.该异常核型可能与预后不良相关.结论 合并继发性der(9)t(9;22)(q34;q11)inv(9)(p22q34)异常的Ph阳性白血病是一种少见但可再现的Ph继发性异常,具有独特的临床和分子遗传学特点.