Bone marrow neoplastic

Bone marrow - plasma cell and lymphoid neoplasms

B lymphoblastic leukemia/lymphoma with recurrent genetic abnormalities


Topic Completed: 1 February 2013

Minor changes: 19 June 2020

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PubMed Search: B lymphoblastic leukemia E2A-PBX1 TCF3-PBX1

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Cite this page: Mihova D. t(1;19)(q23;p13.3). website. Accessed September 22nd, 2021.
Definition / general
  • 5 - 6% of ALL; commonly detected by conventional cytogenetics in children
  • E2A-PBX1 (TCF3-PBX1) is chimeric gene formed by t(1;19)(q23;p13.3) (Mol Cell Biol 1994;14:3938)
  • High WBC counts, frequent CNS involvement
  • In children (Blood 1984;63:721) and adults (Haematologica 2010;95:241), is no longer a poor prognostic factor due to intensive therapy and bone marrow transplantation
Case reports
Microscopic (histologic) description
  • No distinct morphologic findings
Positive stains
  • Typical immunophenotype cytoplasmic µ (cµ), CD10, CD19
  • If cytoplasmic µ negative, can be suspected if strong CD9 and CD34-
Molecular / cytogenetics description
  • Produces fusion transcript of PBX1 and E2A; occurs in balanced and unbalanced forms; unbalanced form is der(19)t(1;19)
  • The reciprocal product of der(1)t(1;19) is lost and the normal chromosome 1 is duplicated (Leukemia 2001;15:95)

  • “Unbalanced translocations” means the exchange of chromosomal material is unequal resulting in extra or missing genes
  • “der” means derivative chromosome - term is used when only one chromosome from a translocation is present, or when one chromosome has two or more structural abnormalities
Molecular / cytogenetics images

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Missing Image

Karyotype (unbalanced)
with loss of der(1)t(1;19)

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