[Oral molecular targeting agents in hematological malignancy].

Molecular target therapy is progressive and promising in various hematological malignancies. Imatinib is now the treatment of choice for chronic-phase chronic myeloid leukemia. Eight-year data from the pivotal trial of imatinib, the IRIS trial, showed high long-term response rates and favorable tolerability profile compared with previous therapies. For patients with primary resistance to imatinib, hematologic disease recurrence, or emergent BCR-ABL kinase domain mutations, the potent second generation tyrosine kinase inhibitors dasatinib and nilotinib are now available. Since the introduction of all-trans retinoic acid (ATRA) in the 1980s, the strategy for treating acute promyelocytic leukemia (APL) has shifted from conventional chemotherapy to cell differentiation. The combination of ATRA and anthracycline-based chemotherapy is currently the standard approach to treat newly-diagnosed APL. Multiple myeloma (MM) is also one of the major therapeutic targets in using molecular based technology. The recent availability of clinical data regarding thalidomide and lenalidomide has provided effective treatment options for patients with both newly diagnosed and relapsed/refractory MM. Overall, this paper focuses on a comprehensive review of the current literature and provides data supporting molecular target therapy for patients with CML, APL, or MM.

Rapidly progressive Epstein-Barr virus-associated lymphoproliferative disorder unpredictable by weekly viral load monitoring.

We report a case of Epstein-Barr virus (EBV)-associated lymphoproliferative disease (LPD) following unrelated bone marrow transplantation (UBMT) for severe aplastic anemia treated with a conditioning regimen that included anti-thymocyte globulin (ATG). The patient showed signs of EBV reactivation as early as 34 days after UBMT. Our weekly schedule for EBV monitoring failed to trace rapid changes in EBV viral load and the patient eventually developed EBV-LPD. However, early intervention with monoclonal antibody against CD20, rituximab, stopped the further progression of EBV-LPD. As several recent reports have suggested, the safety and efficacy of rituximab treatment for EBV-LPD is supported by our limited experience with post transplant EBV-LPD.

Extranodal NK/T cell lymphoma, nasal type, of the small intestine diagnosed by double-balloon endoscopy.

Extranodal NK/T-cell lymphoma (ENKL), nasal type, is rare and the small intestine is quite extraordinary as a primary lesion site. We report a 47-year-old man with ENKL of the small intestine. He was referred to our hospital because of bloody stool and the diagnosis was made by double-balloon endoscopy (DBE) of the small intestine without surgical procedure. His clinical stage was IVB and he was categorized in group 4 by prognostic index of ENKL. He went into complete remission (CR) after intensive chemotherapy (DeVIC) and subsequently underwent allogeneic bone marrow transplantation (BMT). Although he remained in CR for about 8 months after BMT, he died of disease recurrence 14 months after the diagnosis was made. ENKL of the small intestine follows a highly aggressive course. We describe the usefulness of DBE for diagnosis and management for ENKL of the small intestine. Additional cases, however, should be accumulated to establish optimal treatment strategy.

[Chronic eosinophilic leukemia with complex karyotypic abnormalities including trisomy 8].

We report a 61-year-old man with chronic eosinophilic leukemia (CEL). The patient was referred to our hospital because of pyrexia and eosinophilia. He was diagnosed with CEL based on an increase in blasts and eosinophils in his peripheral blood and bone marrow, and clonal complex karyotypic abnormalities including trisomy 8. The FIP1L1-PDGFRA fusion transcript was not detected by RT-PCR analysis. Although he had no obvious organ damage at diagnosis, pulmonary infiltrates in the right lung and multiple skin nodules over his whole body appeared over 4 months and progressed rapidly, accompanied by a marked increase in blasts in his peripheral blood. CEL with trisomy 8 has been reported to be associated with transformation into acute leukemia and granulocytic sarcoma in the literature. It is notable that the present case was associated with complex karyotypic abnormalities and the exceptionally marked disease progression. Further analyses of clinical data as well as molecular genetic findings of CEL without known karyotypic abnormalities leading to constitutive activation of tyrosine-kinase genes are needed to gain insight into the pathogenesis of CEL and to develop a new disease classification and treatment strategies.

A novel variant form of MLL-ELL fusion transcript with t(11;19)(q23;p13.1) in chronic myelomonocytic leukemia transforming to acute myeloid leukemia.

MLL located at 11q23 is fused with a variety of partner genes by recurrent chromosomal translocations in acute leukemias. ELL, the MLL partner gene located on chromosome 19p13.1, encodes an RNA polymerase II transcriptional elongation factor, which also possesses the N-terminal region involved in the inhibition of transcription initiation. Here we report a case of chronic myelomonocytic leukemia (CMML) with a 46,XY,t(11;19)(q23;p13.1) karyotype that transformed to acute myeloid leukemia (AML) without showing any karyotypic evolution. Interphase fluorescent in situ hybridization analysis showed the split MLL signals in 95% of bone marrow cells when the diagnosis of CMML was made and the percentage of blasts was 1.2%. Sequence analysis of reverse-transcriptional polymerase chain reaction product revealed a novel variant form of MLL-ELL transcript in which MLL exon 10 was fused to ELL exon 3. MLL has been fused to ELL exon 2 in all the previously reported MLL-ELL transcripts, which have always been associated with AML. It is deduced that the variant form of MLL-ELL may be defective not only in inhibition of transcription initiation, but also in transcriptional elongation. Thus, a possibility is raised that the unique clinical presentation of the present case with t(11;19)(q23;p13.1) might be related to the variant form of MLL-ELL.

Successful imatinib treatment of cardiac involvement of FIP1L1-PDGFRA-positive chronic eosinophilic leukemia followed by severe hepatotoxicity.

Imatinib is highly effective for the treatment of chronic eosinophilic leukemia (CEL) caused by the FIP1L1-PDGFRA fusion gene. However, its effectiveness for cardiac involvement of CEL has remained unclear. We describe a 46-year-old man with CEL treated with imatinib. Reverse transcriptase-polymerase chain reaction and sequencing analyses revealed a FIP1L1-PDGFRA fusion transcript with FIP1L1 intron 10 fused to PDGFRA exon 12, and fluorescent in situ hybridization analysis confirmed the interstitial deletion in chromosome 4q12. On admission, the patient had left heart failure accompanied by a large thrombus in the left ventricle. After pretreatment with furosemide and prednisolone, we started imatinib treatment at 100 mg/day. Eosinophilia disappeared within 1 week, and the left ventricular thrombus was resolved within 5 months. At 6 months after starting imatinib, the patient showed grade 4 liver dysfunction. A liver biopsy revealed hepatocyte necrosis with lymphocyte infiltration. Fortunately, the FIP1L1-PDGFRA fusion transcript had become undetectable, and imatinib treatment was stopped. The liver dysfunction resolved within a month. Although the CEL relapsed 6 months later, imatinib could be successfully resumed in combination with 25 mg/day of prednisolone. Thus, imatinib may be very effective for treating the early cardiac involvement of FIP1L1-PDGFRA-positive CEL, but it needs to be used cautiously.

A case of paraneoplastic syndrome mimicking adult-onset Still's disease.

A 49-year-old woman was admitted to our hospital because of fever of unknown origin. The patient had long-lasting spiking fever, hepatosplenomegaly, pleural effusion, and skin rash. Laboratory tests showed marked leukocytosis and an extremely high serum ferritin level (240 000 ng/ml) accompanied by disseminated intravascular coagulation and hemophagocytic syndrome. Most of the patient's features were compatible with a diagnosis of adult-onset Still's disease (AOSD), the rash, however, was not a typical rheumatoid rash but multiforme erythema. Biopsy of a breast nodule revealed breast cancer, leading us to a diagnosis of paraneoplastic syndrome mimicking AOSD. Although this is a rare disorder, cases resembling the present one have been reported, indicating the importance of including paraneoplastic syndrome in the differential diagnosis of AOSD.