A unique case of complex variant translocation of t(6;9;22)(p22;q34;q11.2), der(19) in a newly diagnosed patient with chronic myeloid leukemia

A Unique Three-Way Variant Philadelphia Chromosome t(6;9;22)(p21.3;q34;q11.2) in a Newly Diagnosed Patient with Chronic Myeloid Leukemia Responded to Flumatinib

Background

Chronic myeloid leukaemia (CML) is a clonal malignant disorder of a pluripotent hematopoetic stem cell characterized by the presence of Philadelphia (Ph) chromosome in more than 90% of patients. However, about 5–10% of CML patients show a variant Ph translocation, involving one or more chromosomes in addition to 9 and 22. The treatment and prognostic impact of such additional abnormalities is not known. Herein, we report a unique case of a three-way translocation variant in CML and responded to flumatinib.

Case Presentation

A 22-year-old Asian female who presented with leukocytosis was diagnosed with CML. Cytogenetic karyotyping analysis showed 46,XX,t(6;9;22)(p21.3;q34;q11.2). She was treated with flumatinib, and MR5.0 (BCR-ABL1 IS≤0.001%, international scale) was achieved after three months of continuous treatment.

Conclusion

This was the 5th case of t(6;9;22), in particular, a new variant Ph translocation, and the first successful case treated with flumatinib in the world.

Atypical presentation of patients with chronic myeloid leukemia in chronic phase—Case report

The presence of the translocation t(9;22)(q34;q11), leading to the BCR::ABL1 fusion transcript, is the hallmark of chronic myeloid leukemia (CML). Nevertheless, atypical presentation at diagnosis can be challenging. However, although most patients with CML are diagnosed with the e13a2 or e14a2 BCR::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. To date, there is limited evidence on the efficacy of front-line second-generation tyrosine kinase inhibitors for this genotype. Here, we report two patients, in whom the diagnosis of CML was challenging. The use of primers recognizing more distant exons from the common BCR::ABL1 breakpoint region correctly identified the atypical BCR::ABL1 e6a2 fusion transcript. Treatment with the second-generation tyrosine kinase inhibitor nilotinib was effective in our patient expressing the atypical e6a2 BCR::ABL1 fusion transcript.

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).

Management of chronic myeloid leukemia presenting with isolated thrombocytosis and complex Philadelphia chromosome: A case report

RATIONALE

Chronic myelogenous leukemia (CML) with thrombocytosis and complex chromosomal translocation is extremely rare in clinical setting. Here, we reported the clinical and pathological characteristics of CML patients, which were characterized by thrombocytosis and complex Philadelphia chromosome translocation. Moreover, we also introduced our therapeutic schedule for this patient as well as review relative literature.

PATIENT CONCERNS

A 24-year-old female presented with night sweating, fatigue, and intermittent fever for 1 month.

DIAGNOSIS

Fluorescence in situ hybridization results revealed that breakpoint cluster region (BCR)-Abelson (ABL) gene fusion in 62% of the cells and karyotyping showed a complex 3-way 46, XY, t(9;22;11) (q34;q11;q13) [19/20] translocation. This patient was diagnosed with CML complicated with thrombocytosis and complex Philadelphia chromosome translocation.

INTERVENTIONS

The patients received continuously oral imatinib mesylate tablets (400 mg) once a day.

OUTCOMES

After treatment with imatinib for 3 months, the BCR/ABLIS was less than 0.1% and achieved major molecular response. Moreover, the BCR/ABLIS of this patient achieved major molecular response. The BCR/ABLIS values at 6 months and 12 months were less than 0.01% and 0.0032%, respectively. And no BCR/ABL fusion was detected in the next 2 years follow-up period.

LESSONS

Imatinib might represent a preferred therapeutic option for CML patients with rare thrombocytosis and complex chromosomal translocation. In addition, BCR/ABL fusion gene examination in patients with thrombocytosis might represent an effective strategy to avoid the misdiagnosis of this specific CML population.