Management of chronic myeloid leukemia presenting with isolated thrombocytosis and complex Philadelphia chromosome

Abstract

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/ABL IS was less than 0.1% and achieved major molecular response. Moreover, the BCR/ABL IS of this patient achieved major molecular response. The BCR/ABL IS 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.

A Case of JAK2V617F-Negative Myeloproliferative Neoplasm in a Young Female Presenting With Extreme Thrombocytosis

“…Unlike regular ABL1, this protein features an enzymatic domain with heightened and constant tyrosine kinase activity due to its fusion with BCR. This uncontrolled tyrosine kinase activity has been associated with the underlying mechanisms of CML [ 1 ].…”

“…Consequently, there is an excessive presence of granulocytes and their immature precursors, occasionally accompanied by blast cells. The defining genetic abnormality is the translocation of t(9;22)(q34;q11.2), leading to the formation of the BCR/ABL1 fusion gene, commonly referred to as the Philadelphia chromosome [ 1 ]. CML constitutes 20% of all adult leukemia cases.…”

Epidemiology of Chronic Myeloid Leukemia in Tunisia

“…Only 12.5% of patients had WBC < 50 000 elts/mm 3 , 33.3% had WBC > 200 000 elts/mm 3 15 patients presented with pronounced thrombocytosis and moderate leucocytosis and who were referred with a suspected diagnosis of essential thrombocythemia [14].…”

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

“… 3 Although more than 90% of CML patients are associated with typical t(9; 22)(q34; q11), but about 5–8% of newly diagnosed CML patients are associated with complex variant Ph (vPh) chromosome, involving one or more chromosomes in addition to 9 and 22. 4 The mechanism of vPh chromosome translocations generation and its effect on prognosis is unclear, but may further classify CML in specific subsets requiring different therapeutic approaches. However, some previous studies have suggested that CML patients with vPh chromosome may have a worse prognosis than patients with typical translocations, including 3 cases with CML with three-way complex vPh t(6;9;22) chromosome translocations.…”