B-Lymphoid Blast Phase-Chronic Myeloid Leukemia: Current Therapeutics.

Blast crisis (BC) is one of the most dreaded complications of chronic myeloid leukemia (CML). Fortunately, the incidence of BC has diminished markedly in the BCR-ABL tyrosine kinase inhibitor (TKI) era. The primary objective of initial treatment in BC is to achieve a second chronic phase (CP) and to proceed to an allogeneic stem cell transplantation (SCT) in eligible patients. The clinical outcome of patients with CML BC remains unsatisfactory, even with highly potent TKIs, as remissions are short lived and there is an unmet need for novel therapies. We provide a comprehensive summary reviewing the current management of Lymphoid BC.

Interphase FISH for BCR-ABL1 rearrangement on neutrophils: A decisive tool to discriminate a lymphoid blast crisis of chronic myeloid leukemia from a de novo BCR-ABL1 positive acute lymphoblastic leukemia.

Discrimination between lymphoid blast crisis of chronic myeloid leukemia (CML) and de novo BCR-ABL1 positive acute lymphoblastic leukemia (ALL) represents a diagnostic challenge because this distinction has a major incidence on the management of patients. Here, we report an uncommon pediatric case of ALL with cryptic ins(22;9)(q11;q34q34) and p190-type BCR-ABL1 transcript. We performed interphase fluorescence in situ hybridization (FISH) for BCR-ABL1 rearrangement on blood neutrophils, which was positive consistent with the diagnosis of lymphoid blast crisis of CML. This case illustrates the major interest of interphase FISH for BCR-ABL1 rearrangement on blood neutrophils as a decisive method to discriminate a lymphoid blast crisis of CML from a de novo BCR-ABL1 positive ALL.

Very long survival in complete cytogenetic remission in an adolescent with lymphoid blast crisis of chronic myeloid leukemia after treatment with intensive ALL-directed chemotherapy combined with continuous imatinib.

An 11-year-old male was diagnosed with chronic-phase chronic myeloid leukemia (CML) in 1998 and received therapy with interferon-α2b and low-dose cytarabine. In 6 years, he progressed to lymphoid blast crisis and received induction chemotherapy with prednisolone, vincristine, daunorubicin, and l-asparaginase concomitantly with imatinib 400 mg/day, and continuation with vincristine + prednisolone, cytarabine + etoposide, vincristine + l-asparaginase, cyclophosphamide + etoposide, and 6-mercaptopurine + methotrexate. Complete molecular response (MR) was achieved and therapy was continued with imatinib 800 mg/day. He relapsed to chronic-phase CML after interruption of imatinib and regained MR after its restart. The patient is alive 17.5 years after CML diagnosis and 11.5 years after lymphoid blast crisis.

DNA copy number alterations mark disease progression in paediatric chronic myeloid leukaemia.

Early recognition of children with chronic phase chronic myeloid leukaemia (CML-CP) at risk for developing a lymphoid blast crisis (LyBC) is desirable, because therapy options in CML-LyBC are limited. We used Multiplex Ligation-dependent Probe Amplification to determine whether B-cell lymphoid leukaemia-specific copy number alterations (CNAs) (e.g. IKZF1, PAX5, CDKN2A deletions) could be detected in CML-CP and may be used to predict disease progression to LyBC. CNAs were detected in all patients with CML-LyBC, but in none of the 77 patients with CML-CP. Based on this study we conclude that CNAs remain a hallmark of disease progression.

Extramedullary T-lymphoblastic blast crisis in a young male with chronic myeloid leukemia: A rare presentation diagnosed on cytology and flow cytometric immunophenotyping.

BACKGROUND: Extramedullary blast proliferations (EBPs) are known to occur in around 15% of chronic myeloid leukemia (CML) patients in the blast phase. Immunophenotypically, the EBPs are commonly myeloid as compared to the lymphoid. Amongst the lymphoid EBPs, T-lymphoblastic type is considerably rare. Furthermore, the occurrence of EBPs at the initial clinical presentation is extremely rare and such presentations almost always portend the occurrence of an imminent hematological blast crisis shortly. CASE: A 25-year-old male presented with abdominal fullness for 1 month. There was no history of abdominal pain, vomiting, jaundice, weight loss, or night sweats. On clinical examination, the patient was found to have pallor and was febrile. There was hepatosplenomegaly and a single, firm, mobile, left posterior cervical lymph node measuring 1.5 × 1 cm was palpable. Routine blood counts revealed anemia, leukocytosis, and thrombocytopenia. A fine-needle aspiration (FNA) from the cervical revealed T-lymphoid EBP, confirmed by flow cytometry. Subsequently, his bone marrow examination revealed a diagnosis of CML with BCR::ABL1 fusion. Thus, a final diagnosis of CML with extramedullary T-lymphoid blast crisis localized to the cervical lymph node was rendered. CONCLUSIONS: The present report, besides highlighting the utility of FNA cytology in rendering such challenging diagnoses, also reiterates the significance of ancillary techniques, such as flow cytometry, which play a key role in early diagnosis and exact characterization of such rare and aggressive hematolymphoid neoplasms.

Saudi Arabian CML patient with a novel four-way translocation at t(9;22;5;2)(q34;q11.2;p13;q44).

BACKGROUND: The vast majority of chronic myeloid leukemia (CML) patients have a single translocation t(9;22)(q34;q11), BCR/ABL1 fusion genes, which is regarded as the hallmark of CML. However, around 5 to 10% of CML patients exhibit the involvement of a third chromosome. In some very rare cases a fourth or even fifth chromosome can be involved with the t(9;22). METHODS: This case report is based on a 40-year-old Saudi Arabian male patient, diagnosed with CML in lymphoid blast crisis, and observed to have a four-way 46 XY, t(9;22;5;2)(q34;q11.2;p13;q44) translocation. The BCR/ABL1 fusion was identified by fluorescent in situ hybridization (FISH). Additionally, the BCR/ABL1 p210 mRNA fusion transcripts were identified by a molecular test. RESULTS: The clinical and prognostic impact of additional partner chromosomes to t(9;22) remains unknown. The CML patient with this novel four-way translocation t(9;22;5;2) progressed to blast crisis and was resistant to Tyrosine Kinase Inhibitor (TKI) therapy. Therefore, this case is more in alignment with the negative impact of additional partner chromosomes to the translocation at t(9;22). CONCLUSION: Here we report for the first time a novel four-way translocation at t(9;22;5;2)(q34;q11.2;p13;q44).

The third-time chronic myeloid leukemia in lymphoblastic crisis with ABL1 kinase mutation induced by decitabine, dexamethason combined with nilotinib and dasatinib.

Blast crisis (BC) is the major remaining challenge in the management of chronic myeloid leukemia (CML). The prognosis of the BC patient who carries ABL kinase mutation is very poor. One patient, with lymphoid CML-BC third time, was detected with T315A/F359I/M244V compound mutation by direct sequencing after treatment with tyrosine kinase inhibitions three years. The patient was treated with decitabine, dexamethasone, in combination with nilotinib and dasatinib. Then this patient received a complete hematologic response and cytogenetic response after two cycles of treatment.

Significance Analysis of Microarrays (SAM) Offers Clues to Differences Between the Genomes of Adult Philadelphia Positive ALL and the Lymphoid Blast Transformation of CML.

Philadelphia positive malignant disorders are a clinically divergent group of leukemias. These include chronic myeloid leukemia (CML) and de novo acute Philadelphia positive (Ph(+)) leukemia of both myeloid, and lymphoid origin. Recent whole genome screening of Ph(+)ALL in both children and adults identified an almost obligatory cryptic loss of Ikaros, required for the normal B cell maturation. Although similar losses were found in lymphoid blast crisis the genetic background of the transformation in CML is still poorly defined. We used Significance Analysis of Microarrays (SAM) to analyze comparative genomic hybridization (aCGH) data from 30 CML (10 each of chronic phase, myeloid and lymphoid blast stage), 10 Ph(+)ALL adult patients and 10 disease free controls and were able to: (a) discriminate between the genomes of lymphoid and myeloid blast cells and (b) identify differences in the genome profile of de novo Ph(+)ALL and lymphoid blast transformation of CML (BC/L). Furthermore we were able to distinguish a sub group of Ph(+) ALL characterized by gains in chromosome 9 and recurrent losses at several other genome sites offering genetic evidence for the clinical heterogeneity. The significance of these results is that they not only offer clues regarding the pathogenesis of Ph(+) disorders and highlight the potential clinical implications of a set of probes but also demonstrates what SAM can offer for the analysis of genome data.