Three-Way Translocation t(12;15;17) (p13;q24;q21) Found in Acute Promyelocytic Leukemia with Basophilic Differentiation.

Acute promyelocytic leukemia is a rare form of acute myeloid leukemia in which immature promyelocytes abnormally proliferate in the bone marrow. In most cases, the disease is characterised by the translocation t(15;17) (q24;q21), which causes the formation of PML::RARA, an oncogenic fusion protein responsible for blocking myeloid differentiation and survival advantage. Here, we present a case of acute promyelocytic leukemia with two unusual features: basophilic differentiation and a three-way translocation involving chromosomes 12, 15 and 17. In the few cases reported, basophilic differentiation was associated with a poor prognosis. In contrast, our patient responded promptly to the standard treatment with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) and obtained complete remission. To our knowledge, this is the first report of basophilic acute promyelocytic leukemia with the three-way translocation t(12;17;15) (p13; q24;q21).

Second-line Dasatinib Therapy Improved Compliance and Deep Molecular Responses in Imatinib-intolerant Chronic Myeloid Leukemia Patients.

BACKGROUND/AIM: Imatinib (IM) is the standard-of-care treatment for most chronic myeloid leukemia (CML) patients in chronic phase (CP). However, some patients suffer from low-grade side-effects that, in the long run, severely affect the quality of life and require treatment discontinuation due to toxicities. Fortunately, there are several therapeutic alternatives for these patients. Among them, the second-generation tyrosine kinase inhibitor dasatinib (DAS), used as second-line treatment, has shown to be a valid option in patients with CP-CML after intolerance to prior IM. PATIENTS AND METHODS: Herein, we report on seven CP-CML patients who achieved a stable major molecular response (MMR) with IM-therapy, but were shifted to DAS treatment due to recurrent low-grade IM-intolerances (grades 1-2). RESULTS AND CONCLUSION: All patients received conventional DAS treatment with a median daily dose of 83.3 mg. Treatment was well tolerated and side-effects were mild. In addition, after a median follow-up of 25 months (range=24-43 months) a deep molecular response (DMR) (either MR4 or MR4.5) was achieved in all patients after 24 months of treatment. This finding, although limited to a small cohort of CP-CML patients, supports the view that a therapy switch from IM to DAS induces a reduction of symptom burden, improves patient compliance and shows clinical efficacy in achieving and sustaining deep molecular responses.

Optimal Response in a Patient With CML Expressing BCR-ABL1 E6A2 Fusion Transcript With Nilotinib Therapy: A Case Report.

BACKGROUND/AIM: The Philadelphia chromosome is considered the hallmark of chronic myeloid leukemia (CML). However, although most patients with CML are diagnosed with the e13a2 or e14a2 breakpoint cluster region (BCR)-Abelson 1 (ABL1) fusion transcripts, about 5% of them carry rare BCR-ABL1 fusion transcripts, such as e19a2, e8a2, e13a3, e14a3, e1a3 and e6a2. In particular, the e6a2 fusion transcript has been associated with clinically aggressive disease frequently presenting in accelerated or blast crisis phases; there is limited evidence on the efficacy of front-line second-generation tyrosine kinase inhibitors for this genotype. CASE REPORT: We describe a case of atypical BCR-ABL1 e6a2 fusion transcript in a 46-year-old woman with CML. RESULTS: The use of primers recognizing more distant exons from the common BCR-ABL1 breakpoint region correctly identified the atypical BCR-ABL1 e16a2 fusion transcript. Treatment with second-generation tyrosine kinase inhibitor nilotinib was effective in this patient expressing the atypical e6a2 BCR-ABL1 fusion transcript.

Unusual Karyotype in Acute Myelomonocitic Leukemia: A Case Report.

BACKGROUND/AIM: Acute myeloid leukemia is well characterized by chromosomal aberrations that correspond to various subtypes of acute leukemias. The t(8;21)(q22;q22) is a frequent chromosomal abnormality strongly associated with acute myeloblastic leukemia with maturation (AML-M2), but is rarely associated with other subtypes. Translocation involving a third chromosome could produce new genetic rearrangements that lead to leukemogenesis. PATIENTS AND METHODS: Conventional cytogenetic analysis and fluorescence in situ hybridization (FISH) were performed to identify the karyotype. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the AML1/ETO transcript. RESULTS/CONCLUSION: We herein report a novel rearrangement with a three-way translocation involving chromosomes 8, 21 and another unknown chromosome, in an 83-year-old female patient diagnosed as AML-M4, with an ALM1/ETO negative transcript. This is an uncommon case of AML-M4 with three-way translocation in a new variant of t(8;21) acute myeloid leukaemia. The detailed mechanism of different phenotype expression is unclear. Further study is needed to identify the leukemogenetic transformation resulting from t(8;21) translocation.

Influence of complex variant chromosomal translocations in chronic myeloid leukemia patients treated with tyrosine kinase inhibitors.

UNLABELLED: Cytogenetic variants of the Philadelphia (Ph) chromosome can be observed in 5-8% of patients diagnosed with Chronic Myelogenous Leukemia (CML), and usually involve at least one chromosome other than 9 and 22. Despite the genetically heterogeneous nature of these alterations, available data indicate that CML patients displaying complex variant translocations (CVTs) do not exhibit a less favorable outcome as compared to individuals presenting conventional Ph-positive CML. PATIENTS AND METHODS: We report our experience with 10 CML patients carrying CVTs among 153 newly diagnosed cases followed at our Institution. RESULTS AND DISCUSSION: Unlike previously published reports, in our series only two CML patients exhibiting CVTs achieved an optimal response to tyrosine kinase inhibitors (TKI) treatment. The remaining eight patients obtained either a suboptimal response or failed drug therapy. Our data suggest that the presence of CVTs at diagnosis might confer an unfavorable clinical outcome, as these genetic alterations might be markers of genomic instability and indicate a higher likelihood of disease progression.