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A 69-year-old man presented with lumbago and was diagnosed with multiple myeloma (IgD-λ type, R-ISS stage II) with bone-destructive lesions in the lumbar spine and sacrum. Chromosome analysis showed t (8;14)(q24;q32) and t (11;14)(q13;q32). Treatment with daratumumab, lenalidomide, and dexamethasone resulted in partial response, but the disease relapsed, with a copy number increase in t (11;14) and abnormal amplification of the 1q21 region. The patient was treated for CMV enteritis, and was admitted to the hospital due to sudden abdominal pain. Gastrointestinal perforation was diagnosed by CT scan showing free air and wall thickening in the small intestine. Emergency surgery was performed, and the tumors in the perforated area were positive for CCND1 but negative for MYC on immunostaining. The patient's general condition did not improve after the surgery and he died. Pathological autopsy revealed extramedullary infiltration of multiple organs in addition to the small intestine. Extramedullary infiltration is thought to be caused by clonal evolution, and further research is warranted to clarify its pathogenesis and establish effective therapeutic strategies in high-risk patients.

A 41-year-old woman with right shoulder pain was found to have multiple tumors with osteolysis and M-proteinemia. Abnormal plasma cells (CD38+, CD138+, Igλ≫κ) were detected in 1.4% of bone marrow nucleated cells, and G-banding analysis revealed a 46,XX,t (8;14), (q24;q32) karyotype in 4 of 20 cells analyzed. A biopsy specimen from an extramedullary lesion had a packed proliferation of aberrant plasmacytoid cells with positive IgH::MYC fusion signals on fluorescence in situ hybridization. The patient was diagnosed with symptomatic multiple myeloma and treated with the BLd regimen, which significantly reduced M protein levels. Extramedullary lesions were initially reduced, but increased again after four cycles. The lesions disappeared with subsequent EPOCH chemotherapy and radiation, and complete remission was confirmed. The patient was then treated with high-dose chemotherapy with autologous peripheral blood stem cell transplantation. Complete remission was maintained for over one year with lenalidomide maintenance therapy. A solitary IgH::MYC chromosomal translocation is extremely rare in multiple myeloma and may be associated with high tumor proliferative capacity, multiple extramedullary lesions, and poor prognosis. Combined therapeutic modalities with novel and conventional chemotherapy and radiation might be a promising treatment strategy for patients with this type of multiple myeloma.

Multiple myeloma (MM) is characterized by genomic instability, which causes multiple genetic and chromosomal alterations and leads to disease progression and therapeutic resistance. Overlapping mechanisms, including defective genome repair machinery such as the loss of TP53 activity, as well as chromosomal segregation error represented by the abnormality of mitotic checkpoint kinases such as BUB1, cell cycle dysregulation, and tumor environment, cause structural and numerical chromosomal abnormalities. Cytogenetic abnormalities are important prognostic factors, and they are also linked to the use of proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, and the BCL2 inhibitor venetoclax. We developed new diagnostic modalities for chromosomal analysis to improve the sensitivity and convenience of chromosomal diagnosis. The immunophenotyped-suspension-multiplex (ISM)-fluorescence in situ hybridization (FISH) can use imaging flow to examine three IGH-related chromosomal translocations at the same time. We also created a new FISH method called amplified FISH (amFISH) to detect microdeletion involving narrow chromosomal regions (approximately<100 kb), such as the microdeletions of 1p32 (CDKN2C) or of 14q32 (TRAF3), by using a fluorescent antibody to amplify the signals of small probes. Even in the era of clinical sequencing, these convenient modalities may hasten the cytogenetics-oriented therapeutic approach for MM.

In acute myeloid leukemia (AML), EVI1 rearrangement represented by inv(3)(q21q26) or t(3;3)(q21;q26) causes EVI1 overexpression via structural rearrangement of an enhancer, and confers poor prognosis. My colleagues and I performed a mutational analysis of EVI1-rearranged myeloid neoplasms and identified SF3B1, a core RNA splicing factor, as the most commonly co-mutated gene. Indeed, latent leukemia development in transgenic mice bearing the humanized inv(3)(q21q26) allele was significantly accelerated by co-occurrence of Sf3b1 mutation. Intriguingly, we found that this SF3B1 mutant induced mis-splicing of EVI1 itself, which generated an aberrant EVI1 isoform with in-frame insertion of 6 amino acids near the DNA-binding domain of EVI1. This aberrant EVI1 isoform exhibited DNA-binding activity different from wild-type EVI1 and significantly enhanced the self-renewal capacity of murine hematopoietic stem cells. We also identified the cryptic branch point and exonic splicing enhancer required for this EVI1 mis-splicing induced by the SF3B1 mutant. These data provide a basis for further elucidation of the molecular mechanism and potential therapeutic candidates for EVI1-rearranged AML.

A 28-year-old female was diagnosed with acute myeloid leukemia (AML) due to t (8;21) (q22;q22.1); RUNX1-RUNX1T1 at 21 weeks of gestation. Because no adverse prognostic genetic mutations were discovered, we decided to continue the pregnancy without chemotherapy for as long as possible. After careful monitoring with blood tests every two weeks, the disease did not progress until full-term, and a cesarean section was performed at 39 weeks of gestation. About two months after delivery, blasts in the peripheral blood increased to 46.5%, and myeloblasts in the bone marrow increased to 21.2%. The patient received idarubicin and cytarabine induction therapy, followed by three cycles of high-dose cytarabine consolidation therapy, and complete remission was maintained. Here we report a rare case who could avoid chemotherapy until full-term labor without progression of AML.

der(1;7)(q10;p10) is a derivative chromosome generated by an unbalanced translocation between chromosomes 1 and 7 during DNA replication. It was first described in 1980, over 40 years ago, in a case report of three patients with myelofibrosis and myeloid metaplasia. This unbalanced translocation has been identified as a characteristic entity within myeloid neoplasms. Recent clinical and genetic studies comparing der(1;7)(q10;p10)(+) against -7/del(7q) have revealed that patients with der(1;7)(q10;p10)(+) MDS have a better prognosis and a unique mutational profile. This review discusses the clinical and genetic features of der(1;7)(q10;p10)(+) myeloid neoplasms.

The unbalanced translocation der (1;7)(q10;p10) is a characteristic cytogenetic abnormality observed in myelodysplastic syndrome (MDS). A 63-year-old man presented to our hospital with fever and lung disease. The chromosomal analysis of bone marrow cells showed 46, XY, +1, der (1;7)(q10;p10) in all four metaphases. The patient was diagnosed with MDS. Bronchoscope examination revealed organizing pneumonia. The patient's eosinophil count rose to 39% after 30 days. His fever and dyspnea worsened, and a skin rash (systemic erythema) appeared simultaneously. Therefore, the patient was commenced on azacitidine and corticosteroids. Although treatment with both drugs could control disease progression transiently, the WT-1 value and the percentage of myeloblasts in the patient's bone marrow increased. Therefore, the patient received hematopoietic stem cell transplantation from his haplo-identical donor daughter. Some reports have demonstrated that patients with MDS with der (1;7)(q10;p10) have better prognosis than those with other abnormalities, such as -7/7q-. However, reported cases with severe complications show very poor prognosis. MDS with der (1;7)(q10;p10) complicated by eosinophilia and organizing pneumonia have not been reported, and its prognosis is expected to be very poor. Our case suggests that such cases might quickly require hematopoietic stem cell transplantation before the disease worsens.

Variants of the t (8;21) (q22;q22) involving chromosome 8, 21, and other chromosomes account for about 3% of all t (8;21) (q22;q22) in patients with acute myeloid leukemia (AML). However, the prognosis of AML with variant t (8;21) remains unknown due to the scarcity of reported cases. Herein we report a case of AML with t (6;21;8) (p23;q22;q22). Fluorescence in situ hybridization confirmed a RUNX1-RUNX1T1 fusion signal on the derivative chromosome 8. This is the first report on a variant of t (8;21) involving the breakpoint 6p23. After induction chemotherapy, our patient achieved complete remission and has been stable for four years.

It is well documented that multiple myeloma (MM) originates in a single plasma cell transformed by chromosome 14q translocations or chromosomal hyperdiploidy and evolves with the accumulation of point mutations of driver genes and/or cytogenetic abnormalities. Furthermore, disease progression is accomplished by branching patterns of subclonal evolution from reservoir clones with a propagating potential and/or the emergence of minor clones, which already exist at premalignant stages and outcompete other clones through selective pressure mainly by therapeutic agents. Each subclone harbors novel mutations and distinct phenotypes, including drug sensitivities. Generally, mature clones are highly sensitive to proteasome inhibitors (PIs), whereas immature clones are resistant to PIs although could be eradicated by immunomodulatory drugs (IMiDs). The branching evolution is a result of the fitness of different clones to the microenvironment and their evasion of immune surveillance; therefore, IMiDs are effective for MM with this pattern of evolution. In contrast, ∼20% of MM evolve neutrally in the context of strong oncogenic drivers, including high-risk IgH translocations, and are relatively resistant to IMiDs. Treatment strategies considering the genomic landscape and the pattern of clonal evolution may further improve the treatment outcome of MM.

An 82-year-old Japanese male patient was initially diagnosed with lymphocytosis. His complete blood count revealed a white blood cell count of 30.9×10 9 /l with 81% abnormal lymphocytes. The abnormal lymphocytes included monoclonal clones of CD38 + and CD138 + cytoplasmic κ + and IgG-κ M-protein, which led to the final diagnosis of plasma cell leukemia (PCL). Bortezomib and dexamethasone therapy was initiated, but the patient succumbed to the disease on the 8th day of hospitalization. A cytogenetic examination revealed a t (9;14)(p13;q32) translocation and the Western blotting confirmed high PAX5 expression. Similar to our present case, PCL cases with "lymphocytosis" have been widely reported, which some speculating the involvement of PAX5 overexpression in the pathogenesis. Such cases, including ours, may be classified as a unique group of disorders (PCL presenting as "lymphocytosis"), which requires accurate differential diagnosis and subsequent urgent multidisciplinary intensive treatment.

Leukemias diagnosed in <1-year-old infants generally have an aggressive clinical nature and unique biological characteristics. Acute lymphoblastic leukemia (ALL) in infants is still intractable and difficult to treat as compared with other pediatric ALLs, for which considerable progress in treatment outcomes has been recently achieved. Infant leukemia cells frequently carry chromosome translocations involving the 11q23 locus, resulting in the rearrangement and fusion of the KMT2A (MLL) gene. Among several KMT2A fusion genes, KMT2A-AFF1 (MLL-AF4) fusion is characteristically observed in neonatal and infant ALL, representing a hallmark of poor prognosis. The cytogenetic/molecular abnormalities t (1;22)(p13.3;q13.1)/RBM15-MKL1 and t (8;16)(p11.2;p13.3)/KAT6A-CREBBP (MOZ-CBP) are also well-known in acute myeloblastic leukemia in this population. Although many neonatal leukemias occurring within the first 28 days of birth are refractory, spontaneous remissions are occasionally observed, especially in the case of t (8;16). Therefore, international collaborative studies are necessary to improve understanding and facilitate the development of better treatment for this rare disease. Thus, this study summarizes the recently reported clinical, cytogenetic, and molecular biology aspects of neonatal and infant leukemias.

Chronic myeloid leukemia (CML) is a clonal hemopoietic stem cell disorder characterized by reciprocal translocation between the long arms of chromosomes 9 and 22 that produces the fusion BCR-ABL1 gene. Major manifestations in CML patients are increased white cell count and splenomegaly. In this case, the patient presented with aseptic meningitis and showed symptoms, such as disorientation, double vision, and neurogenic bladder disorder. Pulse steroid and antibiotic treatment was ineffective for these symptoms; however, the combination therapy with these drugs and dasatinib was very effective. Moreover, our patient had myelopathy that could have been induced by dasatinib after the treatment was started. To our knowledge, this is the first report of meningitis of the paraneoplastic syndrome associated with CML.

Acute lymphoblastic leukemia (ALL) in infants remains an intractable and difficult-to-treat leukemia as compared to other pediatric ALLs, for which considerable progress has been achieved in terms of treatment outcomes in recent years. The leukemic cells in infants with ALL frequently carry chromosome translocations involving 11q23, resulting in the rearrangement and fusion of the MLL (KMT2A) gene. Among many MLL fusion genes, MLL-AF4 (KMT2A-AFF1) fusion is characteristically observed in infants with ALL, representing a hallmark of poor prognosis. In MLL-AF4-positive infants with ALL, first leukemic cells with MLL-AF4 were generated in utero. Analysis of several murine and human leukemia models revealed that the target cells for tumorigenesis by MLL-AF4 were not the hematopoietic progenitor cells of the bone marrow, but the early hematopoietic progenitor cells present in the fetal liver during the embryonic period and possibly the undifferentiated cells prior to the commitment to hematopoietic cells in the fetus. Elucidation of the leukemogenic process of infant ALL with MLL-AF4 may lead to early, pre-symptomatic diagnosis of leukemia, resulting in the improvement of prognosis and prevention of the onset of ALL in infants.

A 69-year-old woman with leukocytopenia and thrombocytopenia was referred to our hospital. Her bone marrow comprised 70.5% abnormal promyelocytes that were positive for myeloperoxidase/CD33/CD117 and CD13 (dim) and negative for CD2/CD34/CD56 and HLA-DR. Chromosome analysis of the bone marrow showed t (12;17;15) (p13;q21;q22), and fluorescence in situ hybridization revealed the PML-RARA fusion signal only on the derivative chromosome 15. The patient was diagnosed with acute promyelocytic leukemia (APL) with PML-RARA and was treated using all-trans retinoic acid (ATRA). In peripheral blood (PB), PML-RARA-positive polymorphonuclear cells (PMNs) appeared on the second week and became negative on the sixth week after treatment, whereas PML-RARA-negative PMNs started to increase in number on the sixth week. Molecular remission was confirmed on the 10th week. Quantitative evaluation of the differentiated leukemic cells of APL and recovered cells from normal hematopoiesis in PB can provide useful information for a safer induction therapy. No significant difference was noted in the kinetics of the leukemic cells under ATRA treatment as well as in the clinical features between our patient without RARA-PML and those with t (15;17), which is a cytogenetic evidence for the critical role of PML-RARA in the pathogenesis of APL.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a hematological malignancy, which seems to originate from the precursor of plasmacytoid dendritic cells. Because BPDCN has an aggressive course and poor prognosis, development of new treatment strategies is essential. Next-Generation Sequencing, a recently evolved technology, reveals new molecular mechanism of BPDCN development. Here I will discuss the recent research on the treatment of BPDCN, including the relationship between chromosomal translocation and enhancer hijacking in BPDCN.

A 74-year-old man was admitted to hospital due to suspected acute leukemia. He had a history of thymic carcinoma, which had been treated with carboplatin in combination with either paclitaxel or amrubicin. However, the tumor remained unresponsive to these treatments. Administration of tegafur/gimeracil/oteracil (TS-1) was initiated, which resulted in tumor size reduction and a partial response. However, leukopenia persisted after the last TS-1 treatment, and four years after the initial treatment, increased blast cell counts were found in a blood film . Bone marrow analysis showed blasts with Auer rods, faggot cells, and dysplastic promyelocytes. Flow cytometry was positive for CD13, CD33, CD34, CD117, and myeloperoxidase, but negative for HLA-DR. PML-RARA fluorescence in situ hybridization was positive. Cytogenetic analysis revealed 47,XY,t (15;17) (q22;q21),+21. Thus, therapy-related acute promyelocytic leukemia (tAPL) was diagnosed. The patient achieved and maintained complete remission for more than 20 months by a de novo APL-treatment regimen including all-trans retinoic acid, arsenic trioxide and tamibarotene. Moreover, the thymic carcinoma has remained stable. Although secondary malignancies of thymic carcinoma have been previously reported, therapy-related leukemia, especially tAPL, is very rare.

We report a case of rapidly progressing primary high-grade B-cell lymphoma of the central nervous system with c-Myc translocation and Bcl-2 protein expression that resulted in the patient's death 45 days after the onset of convulsions. Further, we provide a literature review. CASE:A 74-year-old man was admitted to our hospital for convulsions. Magnetic resonance imaging on admission showed tumorous lesions at the left temporoparietal junction. An open biopsy was performed promptly. The patient was diagnosed with primary high-grade B-cell lymphoma of the central nervous system with c-Myc translocation and Bcl-2 protein expression(<50%). The tumor showed rapid progression postoperatively. The patient did not respond to steroids and died 45 days after the onset of convulsions. CONCLUSION:The c-Myc translocation, showing a strong c-Myc protein positivity, and co-expression of the Bcl-2 protein were poor prognostic factors for the tumor.

Recent technology advances in genomic analysis have unraveled the genomic complexity and evolutionary process of multiple myeloma (MM). Hyperdiploidy or IgH translocations t (4;14), t (11;14), t (6;14), t (14;16), and t (14;20), leading to ectopic overexpression of MMSET/FGFR3, CCND1, CCND3, MAF, and MAFB, respectively, are initiating events. Subsequent secondary events, such as gene copy number alterations, and gene somatic mutations, participate in tumor progression in a branching pattern consistent with Darwin's evolutionary model. Copy number alterations, such as 1q21 amplification and del (17p), have been associated with adverse outcomes. N/KRAS mutations are most commonly found in around 20% of patients, but numerous gene mutations are infrequent. Pathological and clinical relevance of gene mutations combined with cytogenetic abnormalities are currently under investigation. Additionally, detailed genomic analysis of individual patients using targeted-sequencing panels has been facilitated, and efforts toward personalized therapy based on molecular features have begun. This paper outlines MM molecular pathology and its clinical application in Japanese patients.

A 70-year-old man was admitted to our hospital due to fever, lymphadenopathy, and leukocytosis. White blood cell count was 22,700/µl with 92% blastoid cells. Bone marrow examination revealed abnormal lymphoid cell expansion. Abnormal cells expressed surface CD5 (dim), CD10, CD19, CD20, CD23 (dim) antigens, and kappa immunoglobulin light chains. Cytogenetic analysis of bone marrow cells at the time of diagnosis showed t (11:14) (q13;q32), t (14;18) (q32;q21), and t (8;14;18) (q24;q32;q21). Fluorescence in situ hybridization analyses of bone marrow identified translocations of IGH/MYC, IGH/BCL2, and IGH/CCND1. The patient was diagnosed with aggressive B-cell lymphoma with IGH/MYC, IGH/BCL2, and IGH/CCND1 translocation and was treated with various chemotherapies including R-CHOP, R-ESHAP, DA-EPOCH-R, R-hyper-CVAD, and radiotherapy. However, the lymphoma recurred after every chemotherapy session. Finally, he died after 6 months after first admission. Double-hit lymphoma/triple-hit lymphoma has previously been reported to present with an aggressive clinical course. In the present case, co-existence of IGH/CCND1, IGH/MYC, and IGH/BCL2 is very rare. Further clinical and biological investigations are necessary to establish an optimal treatment strategy.

Here, we report the case of a 9-year-old girl with acute myeloid leukemia (AML) developed from systemic mastocytosis (SM). She experienced bladder and rectal disturbance due to an extramedullary nodule in the paraspinal region of the sacrum. Cytogenetic and genetic analyses of leukemic cells revealed the KIT D816Y mutation besides t (8;21) (q22:q22) /RUNX1-RUNX1T1. Despite receiving proton beam therapy after conventional chemotherapy, the patient relapsed after 2 months. As SM-AML with the KIT D816 mutation in adults exhibits a poor prognosis, hematopoietic stem cell transplantation is recommended. Owing to a few reports of SM-AML in children, the standard therapy for pediatric cases has not been established to date. Based on our experience and the related literature, the prognosis of childhood SM-AML could be as poor as in adults. Hence, further investigation, including mutational analyses of the KIT gene, is warranted to establish a risk-oriented strategy for managing childhood SM-AML.

Genetic abnormalities of acute myeloid leukemia (AML) include chromosomal translocations and gene mutations. Commonly observed chromosomal abnormalities in AML are t (8;21), t (15;17), inv (16), and 11q23-related translocations. These aberrations produce RUNX1-RUNX1T1, PML-RARA, CBF-MYH11, and MLL-fusion genes, respectively, which promote leukemic stem cell formation by interfering with hematopoietic differentiation and enhancing the self-renewal capacity of hematopoietic cells. Gene mutations recurrently occur in transcription factors, signaling molecules, tumor suppressor genes, epigenetic regulators, RNA splicing factors, and cohesion complexes, with FLT3, NPM1, and DNMT3A being the most frequently mutated genes in AML. Recent studies disclosed the biological function of mutated genes and their correlation with prognosis. Based on these findings, development of novel therapeutic drugs targeting mutated genes or dysregulated genetic pathways is underway.

The rare chromosomal translocation t(16;21) has been associated with CD56 expression and extramedullary lesions in acute myeloid leukemia (AML). We herein report the first case of the development of isolated pericardial relapse after HLA-haploidentical peripheral blood stem cell transplantation (haplo-PBSCT). A 42-year-old male AML patient with t(16;21)(p11.2;q22) received haplo-PBSCT at partial remission, and he exhibited dyspnea due to massive pericardial effusion 11 months later. The effusion analysis revealed CD56+ leukemic cells, and G-banded karyotyping of the cells demonstrated t(16;21)(p11.2;q22). Salvage chemotherapy was administered, but only a transient improvement of the effusion was achieved. Moreover, the pleural effusion developed without bone marrow relapse.

For a long time, treatment for adult acute lymphoblastic leukemia (ALL) lacked significant improvements. Since 2000, new approaches, such as the treatments of adolescent and young adult ALL using pediatric-like protocols and Ph+ ALL treatments using tyrosine kinase inhibitor-combined chemotherapies. Further improvements are expected from the use of pediatric-like protocols to whole adults, and the use of newly approved anti-cancer drugs, such as inotuzumab ozogamicin and blinatumomab. Furthermore, comprehensive genetic analyses using next generation sequencing technology have recently discovered new recurrent fusion genes of ALL, such as DUX4 fusion genes, ZNF384 fusion genes, and MEF2D fusion genes. In this review, I will introduce these frontline studies and discuss about the treatment of patients with adult ALL.

A 69-year-old man visited a doctor because of systemic lymphadenopathy. Peripheral blood examination revealed leukocytosis, anemia, and decreased platelet count (WBC, 103,060/µl; lymph, 92.2%; Hb, 8.9 g/dl; and Plt, 4.1×10 4 /µl). Bone marrow biopsy revealed that approximately 70% of nucleated cells were small, mature lymphoid cells with positive immunostaining for CD5, CD20, and CD23. He was diagnosed with chronic lymphocytic leukemia (CLL). The IgH/CCND1 translocation and ATM locus loss in 20% and 95% peripheral cells, respectively, were detected by fluorescence in situ hybridization. Immunostaining revealed that cyclin D1 was positive in approximately 30% bone marrow cells. As the positive rate of CCND1 fusion signal was low, the diagnosis of mantle cell lymphoma was excluded. In contrast, signals of ATM locus deletion were detected in most tumor cells. Therefore, we assessed that IgH/CCND1 translocations occurred during the natural clinical course of CLL with ATM locus deletion from the onset of disease. The secondary IgH/CCND1 translocation in CLL is rare, and all reported cases with such translocations received treatments with alkylating agents. This is the first report regarding secondary IgH/CCND1 translocation during the natural clinical course of CLL and may provide insights into CLL pathogenesis.

A 73-year-old man with left parotid gland swelling over 2 months was referred to our hospital in March 201X. Purpura on the lower legs had been recurrent for >20 years. Biopsy of the parotid gland demonstrated diffuse infiltration of abnormal lymphocytes that were negative for CD10 and positive for CD19, CD20, and κ-chain. The Ki-67 positivity was <10%; lymphoepithelial lesions were observed. The patient was diagnosed with extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). Chromosome analysis revealed t (X;14) (p11.2;q32), and fluorescence in situ hybridization (FISH) of metaphase spreads showed three signals of the immunoglobulin heavy chain (IGH) gene on the derivative chromosomes X and 14, besides the normal chromosome 14. CT findings of parotid glands were suggestive of Sjogren syndrome, and biopsy of the purpura on the leg demonstrated leukocytoclastic vasculitis. In the literature, only seven patients with lymphoma and t (X;14) translocation have been reported. Of these, five patients had MALT lymphoma, one had nodal marginal zone lymphoma, and one had diffuse large B-cell lymphoma. In all patients, lymphoma evolved from previous autoimmune diseases. It is suggested that MALT lymphoma with the t (X;14) translocation forms a new entity of lymphoma.

A 70-year-old man with pancytopenia was referred to our hospital. His bone marrow comprised 75.4% leukemic blast cells and increased micromegakaryocytes. The leukemic cells were positive for myeloperoxidase and expressed CD2, CD13, CD33, CD34, CD56, CD117, HLA-DR, and MYC. Chromosomal analysis revealed 45,XY,t (3;8) (q26.2;q24),-7[6]/46,XY[14]. Fluorescence in situ hybridization revealed the rearrangement of the ecotropic viral integration site 1 (EVI1) gene. Thus, the patient was diagnosed as having acute myeloid leukemia (AML) with maturation, according to the WHO classification; he achieved complete cytogenetic remission after two courses of combination chemotherapy using anthracyclines and cytarabine. The t (3;8) translocation is a rare simple variant of the 3q26.2/EVI1 translocation, which is an adverse prognostic factor of AML. Clarifying the clinical features of leukemia in patients with simple variant translocations facilitates the development of therapies.

A 69-year-old man diagnosed with leukocytosis was referred to our hospital in July 201X. The patient was diagnosed as having a myelodysplastic/myeloproliferative neoplasm. However, he presented with leukemia 2 months later. Chromosomal analysis of a bone marrow sample documented that this patient had a normal karyotype. The patient was successfully treated with idarubicin and cytarabine, and he underwent three courses of consolidation therapy. However, he suffered a relapse in May of the following year. A cytogenetic analysis revealed the presence of a t (3;21) (q13;q22) translocation, and fluorescence in situ hybridization of metaphase spreads detected three signals corresponding to the runt related transcription factor 1 (RUNX1) on the derivative chromosomes 3 and 21, besides the normal chromosome 21. Chromosomal translocations in leukemia often involve genes encoding transcription factors, and the RUNX1 is a common target for such translocations. To the best of our knowledge, this is a novel variant of the RUNX1 translocation. Identifying genes associated with translocations in leukemia contributes to novel insights into the mechanisms of disease progression and chemotherapy resistance and also facilitates the development of molecularly targeted therapies.

Double-hit lymphomas are rare tumors that are defined by a chromosomal breakpoint affecting the MYC/8q24 locus in combination with another recurrent breakpoint, mainly a t(14; 18)(q32;q21)involving BCL2. We report a case of a 38-yearold woman with a 2-month history of abdominaldistention. 18F-FDG PET showed multiple positive systemic lymph nodes, positive peritoneum, and multiple positive intra-abdominal masses. Histopathology results of the cervical lymph node were compatible with double-hit follicular lymphoma(Grade 3A)because fluorescence in situ hybridization(FISH)demonstrated both MYC rearrangement and BCL2 gene fusion. She was initially started on R-CHOP(rituximab and doxorubicin, vincristine, cyclophosphamide, and prednisolone), but after one course the regimen was changed to dose-adjusted EPOCH-R(rituximab and doxorubicin, etoposide, vincristine, cyclophosphamide, and prednisolone). However, she showed no response to this chemotherapy regimen or haploidentical stem cell transplantation. The treatment strategy included salvage chemothera- py. An autologous and/or allogeneic hematopoietic transplantation is important for non-responders to DA-EPOCH-R.

A 72-year-old woman was referred to our hospital with complaints of macro-hematuria. The radiographic evaluation including computed tomography (CT) and magnetic resonance imaging (MRI) suggested it to be renal cell carcinoma (RCC) in her right kidney. She underwent laparoscopic nephrectomy. We diagnosed her with renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion, based on pathological findings and break apart of transcription factor E3 (TFE3)by fluorescence in situ hybridization. She was free of recurrence at 8 months postoperatively.

Case: A 71-year-old woman had been diagnosed as having osteosclerotic myeloma (BJP-λ type) three years prior to the current presentation, based on tumor biopsy from the forehead showing plasmacytoma with systemic osteosclerotic lesions. At 71 years of age, she underwent transverse colectomy for a tumor in the hepatic flexure of the large intestine, and it was diagnosed as IgH/CCND-1-positive plasmacytoma of the large intestine. Although serum vascular endothelial cell growth factor (VEGF) was not elevated, the plasmacytoma was largely positive for VEGF staining. She subsequently experienced transformation to aggressive myeloma over a short period of time. Osteosclerotic myeloma is a rare disease that accounts for less than 3% of all myelomas, and requires differentiation from POEMS syndrome. In this case, peripheral nerve symptoms, which are necessary for the diagnosis of POEMS syndrome, were not confirmed. Thus, this case was diagnosed as having osteosclerotic myeloma. By contrast, abnormal IgH/CCND-1 is confirmed in 15% of patients with myeloma, and 25% of those with POEMS syndrome. While it is unclear whether this genetic abnormality is involved in the development of an osteosclerotic lesion, it is expected that data from patients with osteosclerotic myeloma and POEMS syndrome will be accumulated in the future, allowing clarification of the relationship between the genetic abnormality and osteosclerosis.

Outcomes of patients with acute lymphoblastic leukemia (ALL) have improved dramatically with conventional chemotherapy consisting of multiple agents. However, considering the major impact of tyrosine kinase inhibitors in the treatment of Philadelphia chromosome-positive ALL, sensitivities to each chemotherapeutic agent must be appreciated in individual cases to further improve therapeutic outcomes of ALL patients. Recent advances in genome-wide association and comprehensive genetic mutation studies with next-generation sequencing enable the involvement of single nucleotide polymorphisms and acquired genetic mutations in the drug resistance of ALL to be evaluated. Herein, we overview recent findings regarding the mechanisms of drug resistance in ALL. Our observations in a large panel of ALL cell lines are also presented.

A 39-year-old man visited our department complaining of general malaise and appetite loss. He presented with anemia and marked thrombocythemia; his plasma transforming growth factor (TGF)-b concentration was markedly increased and his thrombopoietin (TPO)concentration was decreased. Since the patient's disease had progressed to acute myeloid leukemia (AML) with an increase in the peripheral blast count, he was diagnosed with AML along with t(3;3) (q21;q26.2) through a bone marrow aspiration sample. Remission induction therapy was performed using idarubicin/cytarabine. The patient achieved complete remission. His platelet count returned to the normal range, plasma TGF-b concentration decreased, and serum TPO concentration increased. The patient was treated with azacitidine as post-remission therapy for bone marrow transplantation, following which he underwent allogeneic hematopoietic cell transplantation.

Double- and triple-hit lymphomas (DHL/THL), high-grade B-cell lymphomas with an extremely poor prognosis, are defined by a chromosomal breakpoint affecting the MYC/8q24 locus in combination with another recurrent breakpoint. The successful use of dose-adjusted (DA) EPOCH-R in patients with MYC-positive lymphoma and Burkitt lymphoma (BL) was recently reported. A 74-year-old man with acute renal dysfunction and hyperkalemia was transferred to our emergency center by ambulance. PET-CT revealed a left renal hilar mass enveloping the abdominal para-aortic domain and bladder and hydronephrosis. High (18)F-FDG uptake revealed lymph node, peritoneum, and multiple bone metastases. Analysis of the bone marrow aspirate revealed abnormal lymphoid cells with deeply basophilic cytoplasm and numerous vacuoles resembling Burkitt cells. Chromosomal analysis revealed a complex chromosomal karyotype, including t(14;18)(q32;q21), and FISH analysis confirmed split BCL2, BCL6, and MYC signals. Bone marrow biopsy revealed diffusely infiltrating large abnormal lymphoid cells with a CD10⁺, CD20⁺, BCL2⁺, BCL6⁺, c-MYC⁺ and MUM1(-) immunophenotype. B-cell lymphoma, unclassifiable with features intermediate between diffuse large B-cell lymphoma and BL, was diagnosed. The patient achieved a partial response after eight courses of DA-EPOCH-R chemotherapy. Our experience suggests that DA-EPOCH-R may be an effective treatment for DHL/THL.

TET (Ten Eleven Translocation) family proteins are dioxygenases that convert methylcytosine to hydroxymethylcytosine, and play an important role in the DNA demethylation process. Most notably, TET2 mutations have frequently been identified in myeloid malignancies, such as myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), chronic myelomonocytic leukemia, and acute myeloid leukemias, as well as angioimmunoblastic T-cell lymphoma and a proportion of peripheral T-cell lymphomas. To date, various types of Tet2 knockout/knockdown mice have been generated. Tet2 mutations induce enhanced self-renewal ability and competitive repopulation capacity in hematopoietic stem cells, and various MPN/MDS-like diseases and T-cell lymphoma consequently develop in model mice. These findings appear to have a strong correlation with the recently identified TET2 mutations in a significant proportion of healthy elderly people, and suggest that TET2 mutations lead to a pre-cancer state in hematopoietic stem/progenitor cells. In conclusion, TET2 might play a major role as a gate keeper for hematopoietic stem/progenitor cells preventing them from developing into various hematologic malignancies by acquiring additional disease-specific gene mutations.

A man in his early forties who had undergone 3 years of unsuccessful treatment for infertility due to oligospermia and asthenospermia developed fever and bone pain in December 20XX. He was subsequently diagnosed with acute lymphocytic leukemia. Conventional cytogenetic analysis revealed Robertsonian translocation (RT) with der(13;14)(q10;q10) in addition to the Philadelphia (Ph) chromosome. Dasatinib and prednisolone induced complete remission (CR) with disappearance of the Ph chromosome. However, RT persisted despite achieving CR. We speculate that RT is possibly congenital in our present case and might also have been responsible for the aforementioned infertility. Hematologists should be aware of the possibility that congenital chromosomal disorders might be found incidentally through diagnostic chromosome analysis for leukemia.

A 61-year-old man, who was diagnosed with Bence-Jones protein (BJP)-λ type multiple myeloma, was treated with bortezomib. Although maintenance therapy including lenalidomide was continued, t(9;22)(q34;q11.2) was detected in the marrow cells by a cytogenetic study. The increased incidence of a secondary malignancy after treatment with lenalidomide for multiple myeloma has been highlighted in previous clinical trials; however, reports on the presence of t(9;22)(q34;q11.2) or the onset of chronic myelogenous leukemia have yet to be found. Although the cause of chronic myelogenous leukemia with the lenalidomide treatment is not yet clear, it is an interesting case.

We conducted a retrospective study to evaluate outcomes and prognostic factors of newly diagnosed patients with t(8;21) acute myeloid leukemia (AML). There were 70 patients (43 men and 27 women) with a median age of 48 years old (range, 17∼76 years old). Sixty-five patients achieved complete remission (CR) after induction chemotherapy. Fifty-seven patients received consolidation chemotherapy based on the policy of not performing allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the time of first CR. Twenty-seven of the 57 patients relapsed (relapse rate, 47%). The median time from the achievement of the first CR to relapse was 307 days (96∼1,256 days). A white blood cell count of more than 25,400/μl at diagnosis was associated with a higher relapse rate than a white blood cell count of less than or equal to 25,400/μl (75% vs. 43%, P=0.04). Nineteen of the 25 relapsed patients who received re-induction therapy experienced a second CR (second CR rate, 76%). Twenty-six patients (5 with first CR, 12 with second CR, and 9 without remission) received allo-HSCT. The five-year overall survival and disease-free survival rates were 61% and 45%, respectively. Patients with t(8;21) AML had a high CR rate, but about half of them relapsed. However, this report could not show prognostic factors for the identification of patients who should receive allo-HSCT at the time of their first CR.

The t(16;21)(q24;q22), a rare chromosomal translocation observed mostly in therapy-related acute myelogenous leukemia (AML), produces a RUNX1-CBFA2T3 fusion gene. Here we report a de novo AML case of 1-year-old girl with t(16;21)(q24;q22). In this case, we demonstrated the RUNX1-CBFA2T3 fusion gene and established quantitative RT-PCR for detecting minimal residual disease.