HAEM5:B-lymphoblastic leukaemia/lymphoma with BCR::ABL1-like features

Haematolymphoid Tumours (WHO Classification, 5th ed.)

editContent Update To WHO 5th Edition Classification Is In Process; Content Below is Based on WHO 4th Edition Classification

This page was converted to the new template on 2023-12-07. The original page can be found at HAEM4:B-Lymphoblastic Leukemia/Lymphoma, BCR-ABL1-Like.

(General Instructions – The focus of these pages is the clinically significant genetic alterations in each disease type. This is based on up-to-date knowledge from multiple resources such as PubMed and the WHO classification books. The CCGA is meant to be a supplemental resource to the WHO classification books; the CCGA captures in a continually updated wiki-stye manner the current genetics/genomics knowledge of each disease, which evolves more rapidly than books can be revised and published. If the same disease is described in multiple WHO classification books, the genetics-related information for that disease will be consolidated into a single main page that has this template (other pages would only contain a link to this main page). Use HUGO-approved gene names and symbols (italicized when appropriate), HGVS-based nomenclature for variants, as well as generic names of drugs and testing platforms or assays if applicable. Please complete tables whenever possible and do not delete them (add N/A if not applicable in the table and delete the examples); to add (or move) a row or column in a table, click nearby within the table and select the > symbol that appears. Please do not delete or alter the section headings. The use of bullet points alongside short blocks of text rather than only large paragraphs is encouraged. Additional instructions below in italicized blue text should not be included in the final page content. Please also see Author_Instructions and FAQs as well as contact your Associate Editor or Technical Support.)

Primary Author(s)*

Mark G. Evans, MD, University of California, Irvine

Fabiola Quintero-Rivera, MD, University of California, Irvine

WHO Classification of Disease

Structure	Disease
Book	Haematolymphoid Tumours (5th ed.)
Category	B-cell lymphoid proliferations and lymphomas
Family	Precursor B-cell neoplasms
Type	B-lymphoblastic leukaemias/lymphomas
Subtype(s)	B-lymphoblastic leukaemia/lymphoma with BCR::ABL1-like features

Definition / Description of Disease

In 2009, a high-risk subgroup of B-ALL was identified in children, adolescents, and young adults. The genetic expression is similar to that of BCR-ABL1-positive cases, but without t(9;22)(q34.1;q11.2). Instead, BCR-ABL-1-like B-ALL is a genetically heterogenous disease, often with alterations activating cytokine receptors and tyrosine kinases. Several genetic expression profiles were initially utilized to recognize cases, however, different profiles did not always identify the same patients. Although emerging data advocates the therapeutic use of tyrosine kinase or JAK inhibitors in this disease process, BCR-ABL-like B-ALL is often associated with very high rates of relapse and poor overall survival; thus proper diagnosis is essential.

Synonyms / Terminology

Ph-like B-lymphoblastic leukemia/lymphoma

Epidemiology / Prevalence

• Ph-like ALL comprises up to 15% of childhood B-ALL, and 20 to 25% in adolescents and young adults.
• The incidence in adult patients is controversial—from 13-17% to up to 33% in some reports.
• Higher rates of disease are observed in Hispanic and Native-American populations, and among children with Down syndrome.

Clinical Features

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Signs and Symptoms	EXAMPLE: Asymptomatic (incidental finding on complete blood counts) EXAMPLE: B-symptoms (weight loss, fever, night sweats) EXAMPLE: Fatigue EXAMPLE: Lymphadenopathy (uncommon)
Laboratory Findings	EXAMPLE: Cytopenias EXAMPLE: Lymphocytosis (low level)

editv4:Clinical Features

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The presenting symptoms are similar to those of other ALL patients, with the exception of potentially higher white blood cell counts.

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Sites of Involvement

Bone marrow

Morphologic Features

There are no morphological or cytochemical features that aid in the diagnosis. Blasts range from small to large and chromatin varying from immature to more mature, corresponding to French-American-British classification L1 or L2 subtype.

(Konoplev et al. Am J Clin Pathol. 2017.)

Immunophenotype

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Finding	Marker
Positive (universal)	EXAMPLE: CD1
Positive (subset)	EXAMPLE: CD2
Negative (universal)	EXAMPLE: CD3
Negative (subset)	EXAMPLE: CD4

editv4:Immunophenotype

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Blasts are typically CD19, TdT, and CD10-positive. By flow cytometry, a subset of cases with CRLF2 translocations show very high levels of surface protein expression.

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WHO Essential and Desirable Genetic Diagnostic Criteria

(Instructions: The table will have the diagnostic criteria from the WHO book autocompleted; remove any non-genetics related criteria. If applicable, add text about other classification systems that define this entity and specify how the genetics-related criteria differ.)

WHO Essential Criteria (Genetics)*
WHO Desirable Criteria (Genetics)*
Other Classification

*Note: These are only the genetic/genomic criteria. Additional diagnostic criteria can be found in the WHO Classification of Tumours.

Related Terminology

(Instructions: The table will have the related terminology from the WHO autocompleted.)

Acceptable
Not Recommended

Gene Rearrangements

Put your text here and fill in the table (Instructions: Details on clinical significance such as prognosis and other important information can be provided in the notes section. Please include references throughout the table. Do not delete the table.)

Driver Gene	Fusion(s) and Common Partner Genes	Molecular Pathogenesis	Typical Chromosomal Alteration(s)	Prevalence -Common >20%, Recurrent 5-20% or Rare <5% (Disease)	Diagnostic, Prognostic, and Therapeutic Significance - D, P, T	Established Clinical Significance Per Guidelines - Yes or No (Source)	Clinical Relevance Details/Other Notes
EXAMPLE: ABL1	EXAMPLE: BCR::ABL1	EXAMPLE: The pathogenic derivative is the der(22) resulting in fusion of 5’ BCR and 3’ABL1.	EXAMPLE: t(9;22)(q34;q11.2)	EXAMPLE: Common (CML)	EXAMPLE: D, P, T	EXAMPLE: Yes (WHO, NCCN)	EXAMPLE: The t(9;22) is diagnostic of CML in the appropriate morphology and clinical context (add reference). This fusion is responsive to targeted therapy such as Imatinib (Gleevec) (add reference). BCR::ABL1 is generally favorable in CML (add reference).
EXAMPLE: CIC	EXAMPLE: CIC::DUX4	EXAMPLE: Typically, the last exon of CIC is fused to DUX4. The fusion breakpoint in CIC is usually intra-exonic and removes an inhibitory sequence, upregulating PEA3 genes downstream of CIC including ETV1, ETV4, and ETV5.	EXAMPLE: t(4;19)(q25;q13)	EXAMPLE: Common (CIC-rearranged sarcoma)	EXAMPLE: D		EXAMPLE: DUX4 has many homologous genes; an alternate translocation in a minority of cases is t(10;19), but this is usually indistinguishable from t(4;19) by short-read sequencing (add references).
EXAMPLE: ALK	EXAMPLE: ELM4::ALK Other fusion partners include KIF5B, NPM1, STRN, TFG, TPM3, CLTC, KLC1	EXAMPLE: Fusions result in constitutive activation of the ALK tyrosine kinase. The most common ALK fusion is EML4::ALK, with breakpoints in intron 19 of ALK. At the transcript level, a variable (5’) partner gene is fused to 3’ ALK at exon 20. Rarely, ALK fusions contain exon 19 due to breakpoints in intron 18.	EXAMPLE: N/A	EXAMPLE: Rare (Lung adenocarcinoma)	EXAMPLE: T		EXAMPLE: Both balanced and unbalanced forms are observed by FISH (add references).
EXAMPLE: ABL1	EXAMPLE: N/A	EXAMPLE: Intragenic deletion of exons 2–7 in EGFR removes the ligand-binding domain, resulting in a constitutively active tyrosine kinase with downstream activation of multiple oncogenic pathways.	EXAMPLE: N/A	EXAMPLE: Recurrent (IDH-wildtype Glioblastoma)	EXAMPLE: D, P, T

editv4:Chromosomal Rearrangements (Gene Fusions)

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Tyrosine kinase-type translocations are common and involve ABL1 and other kinases (such as ABL2, EPOR, JAK2, PDGFRB, and CSF1R); more than 30 gene partners have been described. Frequently reported examples include IGH–EPOR of the t(14;19)(q32;p13)/ins(14;19)(q32;p13), EBF1–PDGFRB of the del(5)(q32q33.3), NUP214–ABL1 of the t(9;9)(q34;q34)/del(9)(q34q34), and ETV6–ABL1 of the t(9;12)(q34;p13). Other notable fusions are BCR–JAK2, PAX5–JAK2, STRN3–JAK2, RANBP2–ABL1, RCSD1–ABL1, and MEF2D–CSF1R.

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editv4:Clinical Significance (Diagnosis, Prognosis and Therapeutic Implications).

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• Chromosomal Rearrangements (Gene Fusions)
• Individual Region Genomic Gain/Loss/LOH
• Characteristic Chromosomal Patterns
• Gene Mutations (SNV/INDEL)

• Diagnosis: Definitive diagnosis is based on two major gene expression signatures (DCOG/Erasmus MC and COG/St. Jude).
  • DCOG/Erasmus MC incorporates hierarchal clustering of microarrays using a 110-gene probe set; this genetic signature frequently detected deletions in IKZF1, dic(9;20), and iAMP21 in BCR-ABL1-like B-ALL.
  • COG/St. Jude employs predictive analysis of microarrays using a 257-gene probe set; this genetic signature demonstrated primarily activating kinase or cytokine receptor signaling alterations, in addition to IKZF1 deletions.
• Prognosis: In both pediatric and adult populations, BCR-ABL1-like B-ALL is associated with high rates of relapse and poor prognosis.
  • The median 5-year overall survival rates for children with BCR-ABL1-like B-ALL, adolescents, and young adults was 72.8%, 65.8%, and 25.8%, respectively.
  • Median 5-year-overall survival in adults was 22%, versus 64% in comparable patients with non-BCR-ABL1, non-BCR-ABL1-like, and non-MLL translocation B-ALL.
• Therapeutic Implications: Due to the aggressive nature of the disease, patients are often treated with high-intensity chemotherapy regimens, such as hyper-CVAD or an augmented Berlin-Frankfurt-Münster regimen.
  • However, given the high incidence of fusions involving JAK2, ABL1, ABL2, and other tyrosine kinases, tyrosine kinase inhibitors and JAK inhibitors are now being trialed clinically.

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Individual Region Genomic Gain/Loss/LOH

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Chr #	Gain, Loss, Amp, LOH	Minimal Region Cytoband and/or Genomic Coordinates [Genome Build; Size]	Relevant Gene(s)	Diagnostic, Prognostic, and Therapeutic Significance - D, P, T	Established Clinical Significance Per Guidelines - Yes or No (Source)	Clinical Relevance Details/Other Notes
EXAMPLE: 7	EXAMPLE: Loss	EXAMPLE: chr7	EXAMPLE: Unknown	EXAMPLE: D, P	EXAMPLE: No	EXAMPLE: Presence of monosomy 7 (or 7q deletion) is sufficient for a diagnosis of AML with MDS-related changes when there is ≥20% blasts and no prior therapy (add reference).  Monosomy 7/7q deletion is associated with a poor prognosis in AML (add references).
EXAMPLE: 8	EXAMPLE: Gain	EXAMPLE: chr8	EXAMPLE: Unknown	EXAMPLE: D, P		EXAMPLE: Common recurrent secondary finding for t(8;21) (add references).
EXAMPLE: 17	EXAMPLE: Amp	EXAMPLE: 17q12; chr17:39,700,064-39,728,658 [hg38; 28.6 kb]	EXAMPLE: ERBB2	EXAMPLE: D, P, T		EXAMPLE: Amplification of ERBB2 is associated with HER2 overexpression in HER2 positive breast cancer (add references). Add criteria for how amplification is defined.

editv4:Genomic Gain/Loss/LOH

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Monoallelic (often partial) deletion of the IKAROS transcription factor, encoded by IKZF1, is one of the most frequently observed genetic abnormalities in BCR-ABL1-like B-ALL, although this finding is not specific and not included in the definition.

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Characteristic Chromosomal or Other Global Mutational Patterns

Put your text here and fill in the table (Instructions: Included in this category are alterations such as hyperdiploid; gain of odd number chromosomes including typically chromosome 1, 3, 5, 7, 11, and 17; co-deletion of 1p and 19q; complex karyotypes without characteristic genetic findings; chromothripsis; microsatellite instability; homologous recombination deficiency; mutational signature pattern; etc. Details on clinical significance such as prognosis and other important information can be provided in the notes section. Please include references throughout the table. Do not delete the table.)

Chromosomal Pattern	Molecular Pathogenesis	Prevalence - Common >20%, Recurrent 5-20% or Rare <5% (Disease)	Diagnostic, Prognostic, and Therapeutic Significance - D, P, T	Established Clinical Significance Per Guidelines - Yes or No (Source)	Clinical Relevance Details/Other Notes
EXAMPLE: Co-deletion of 1p and 18q	EXAMPLE: See chromosomal rearrangements table as this pattern is due to an unbalanced derivative translocation associated with oligodendroglioma (add reference).	EXAMPLE: Common (Oligodendroglioma)	EXAMPLE: D, P
EXAMPLE: Microsatellite instability - hypermutated		EXAMPLE: Common (Endometrial carcinoma)	EXAMPLE: P, T

editv4:Characteristic Chromosomal Aberrations / Patterns

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Approximately half of cases demonstrate rearrangements resulting in overexpression of CRLF2. These rearrangements are the result of either translocation of immunoglobin heavy chain enhance locus into CRLF2 (IGH-CRLF2—more commonly seen in adults) or through a cryptic deletion on chromosome X/Y involving the PAR1 psuedoautosomal region, resulting in fusion of CRLF2 to P2RY8 (more commonly seen in children). Very rare alternative translocations involving CRLF2 have also been observed.

[Abnormal FISH results in interphase nuclei from a bone marrow sample using the CRLF2 dual-color, break-apart (Cytocell) and IGH dual-color, break-apart probes, reflective of IGH-CRLF2 fusion]

[Concurrent abnormal karyotype with trisomy 21 and a translocation involving chromosomes X, 14, and 2 in 9 of 13 cells available for analysis. Metaphase FISH with the IGH break-apart probe (Vysis) confirms the presence of 5’ IGH (green signal) on the abnormal chromosome Xp33.1 (CRLF2 locus), highly suggestive on an IGH-CRLF2 fusion rearrangement.

47,XX,+21c[4]/47,idem,der(X)t(X;14)(p33.1;q32),der(2)t(2;14)(p11.2;q11.2)t(X;14),der(14)t(2;14)[5]/46,XX[4].ish der(X)(5’IGH+),der(2)(3’IGH+)]

(Images courtesy of Fabiola Quintero-Rivera, MD)

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Gene Mutations (SNV/INDEL)

Put your text here and fill in the table (Instructions: This table is not meant to be an exhaustive list; please include only genes/alterations that are recurrent or common as well either disease defining and/or clinically significant. If a gene has multiple mechanisms depending on the type or site of the alteration, add multiple entries in the table. For clinical significance, denote associations with FDA-approved therapy (not an extensive list of applicable drugs) and NCCN or other national guidelines if applicable; Can also refer to CGC workgroup tables as linked on the homepage if applicable as well as any high impact papers or reviews of gene mutations in this entity. Details on clinical significance such as prognosis and other important information such as concomitant and mutually exclusive mutations can be provided in the notes section. Please include references throughout the table. Do not delete the table.)

Gene	Genetic Alteration	Tumor Suppressor Gene, Oncogene, Other	Prevalence - Common >20%, Recurrent 5-20% or Rare <5% (Disease)	Diagnostic, Prognostic, and Therapeutic Significance - D, P, T	Established Clinical Significance Per Guidelines - Yes or No (Source)	Clinical Relevance Details/Other Notes
EXAMPLE:EGFR	EXAMPLE: Exon 18-21 activating mutations	EXAMPLE: Oncogene	EXAMPLE: Common (lung cancer)	EXAMPLE: T	EXAMPLE: Yes (NCCN)	EXAMPLE: Exons 18, 19, and 21 mutations are targetable for therapy. Exon 20 T790M variants cause resistance to first generation TKI therapy and are targetable by second and third generation TKIs (add references).
EXAMPLE: TP53; Variable LOF mutations	EXAMPLE: Variable LOF mutations	EXAMPLE: Tumor Supressor Gene	EXAMPLE: Common (breast cancer)	EXAMPLE: P		EXAMPLE: >90% are somatic; rare germline alterations associated with Li-Fraumeni syndrome (add reference). Denotes a poor prognosis in breast cancer.
EXAMPLE: BRAF; Activating mutations	EXAMPLE: Activating mutations	EXAMPLE: Oncogene	EXAMPLE: Common (melanoma)	EXAMPLE: T

Note: A more extensive list of mutations can be found in cBioportal, COSMIC, and/or other databases. When applicable, gene-specific pages within the CCGA site directly link to pertinent external content.

editv4:Gene Mutations (SNV/INDEL)

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In addition to gene translocations, gain-of-function mutations in CRLF2 itself or in its partner gene, IL7RA, have been seen. Alternative alterations activating kinase signaling occur, including activating mutations of FLT3, as well as focal deletions of SH2B3 (also known as LNK).

Herold et al. in 2017 reported a wide variety of molecular alterations in BCR-ABL1-like B-ALL, which was shown to have statistically significant associations with alterations of IKZF1, CRLF2, JAK2, BTG1, and high CRLF2 expression.

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Epigenomic Alterations

Not applicable

Genes and Main Pathways Involved

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Gene; Genetic Alteration	Pathway	Pathophysiologic Outcome
EXAMPLE: BRAF and MAP2K1; Activating mutations	EXAMPLE: MAPK signaling	EXAMPLE: Increased cell growth and proliferation
EXAMPLE: CDKN2A; Inactivating mutations	EXAMPLE: Cell cycle regulation	EXAMPLE: Unregulated cell division
EXAMPLE: KMT2C and ARID1A; Inactivating mutations	EXAMPLE: Histone modification, chromatin remodeling	EXAMPLE: Abnormal gene expression program

editv4:Genes and Main Pathways Involved

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• IKAROS transcription factor: Deletion of IKZF1 results in activation of EBF1, MSH2, and MCL1, leading to B-cell leukemogenesis.
• CRLF2 overexpression: CRFL2 and its cofactor IL7RA form a receptor for thymic stromal-derived lymphopoietin that activates the JAK2-signal transducer and upregulates the transcription 5 pathway.
• Dysregulation of several tyrosine kinase signaling pathways (involving ABL1, ABL2, PDGFRB, CSF1, etc.) results in B-cell progenitor proliferation.

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Genetic Diagnostic Testing Methods

• Flow cytometry for CRLF2 has been shown in some studies to be 100% concordant with FISH results.
• Next-generation sequencing is helpful for detecting copy number changes, single nucleotide variants, and gene fusions involving CRLF2, ABL1, ABL2, JAK2, etc.
• Gene expression profile algorithms, incorporating prediction analysis or hierarchical clustering of microarrays, provide the definitive diagnosis of BCR-ABL1-like B-ALL.

Familial Forms

Families with certain inherited variants of GATA3 (often seen in Native-American populations) are at increased risk of BCR-ABL1-like B-ALL.

Additional Information

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Links

CRLF2

ABL1

ABL2

JAK2

PDGFRB

IKZF1

Pre-B ALL B-lymphoblastic leukemia/lymphoma with BCR-ABL1-like/Ph-like in Pathology Outlines (http://www.pathologyoutlines.com/topic/leukemiaprebbcrabl1like.html)

References

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Notes

*Primary authors will typically be those that initially create and complete the content of a page.  If a subsequent user modifies the content and feels the effort put forth is of high enough significance to warrant listing in the authorship section, please contact the Associate Editor or other CCGA representative.  When pages have a major update, the new author will be acknowledged at the beginning of the page, and those who contributed previously will be acknowledged below as a prior author.

Prior Author(s):

*Citation of this Page: “B-lymphoblastic leukaemia/lymphoma with BCR::ABL1-like features”. Compendium of Cancer Genome Aberrations (CCGA), Cancer Genomics Consortium (CGC), updated 02/10/2025, https://ccga.io/index.php/HAEM5:B-lymphoblastic_leukaemia/lymphoma_with_BCR::ABL1-like_features.