Bone marrow neoplastic

Bone marrow - plasma cell and lymphoid neoplasms

NK and T cell precursor lymphoid neoplasms

T lymphoblastic lymphoma / leukemia

Last author update: 1 March 2013
Last staff update: 5 October 2023

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PubMed Search: T cell acute lymphoblastic leukemia / lymphoma

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Cite this page: Mihova D. T lymphoblastic lymphoma / leukemia. website. Accessed May 19th, 2024.
Definition / general
  • Neoplasm of T lineage lymphoblasts which may form lymphomatous masses, involve blood and bone marrow (Stanford School of Medicine: Precursor T Lymphoblastic Leukemia / Lymphoma [Accessed 13 April 2018])
  • Also called pre T cell acute lymphocytic leukemia / lymphoma (pre-T ALL), T lymphoblastic leukemia / lymphoma (T LBL)
  • Teens and young men (older than B ALL)
  • Most cases begin after birth (Blood 2007;110:3036)
  • T ALL versus T LBL: T ALL has more immature phenotype, CD47 expression, no 11q23 rearrangement, different gene expression profile and may derive from T cell progenitor of bone marrow; T LBL is derived from thymocytes (Pediatr Blood Cancer 2006;47:130, Leuk Lymphoma 2007;48:1745)
  • T ALL constitutes 15% of childhood and 20 - 25% of adult ALL cases
  • T LBL constitutes 85 - 95% of LBL, usually presents as mediastinal mass with no / minimal marrow involvement
  • CNS involvement if untreated
  • T LBL frequently presents with mass in anterior mediastinum, rapid growth, respiratory emergency, pleural effusion
  • Younger (age 16 - 60 years) patients compared to older (61+ years) patients have more hepatosplenomegaly, present with mediastinal mass and lymphadenopathy; myeloid antigens and lineage inappropriate gene rearrangements are less common (Am J Clin Pathol 2002;117:252)
Diagrams / tables

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Rearrangements involving T cell receptor genes

  • T ALL if lymphoblasts are 25% or more of marrow cells; T LBL otherwise
Prognostic factors
  • Chemotherapy cures 60%
  • Patients have earlier relapse, induction failure and isolated CNS relapse compared to pre-B ALL
Microscopic (histologic) description
  • Similar to B cell disease; scant cytoplasm, delicate chromatin, indistinct nucleoli, convoluted nuclear membrane and grooves
  • Frequent mitotic figures; starry sky pattern produced by interspersed benign macrophages
  • Usually features of FAB L1 or L2; pattern in marrow is usually interstitial
  • Lymph nodes: complete architectural effacement or partial involvement with paracortical infiltrate with germinal center sparing
  • Thymus: replacement of normal parenchyma
  • Occasionally eosinophilia and myeloid hyperplasia with variable t(8;13)(p11.2;q11-22) involving FGFR1 gene; some develop myeloid malignancy (MDS, AML or myeloid sarcoma)
Microscopic (histologic) images

AFIP images
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Bone marrow biopsy

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Focal paranuclear acid phosphatase staining

Peripheral smear images

AFIP images
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Markedly elevated leukocyte count

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L2 type (blood smears)

Positive stains
Negative stains
  • CD19, CD20; double negative CD4 / CD8 (40%)
  • Note: ALL with aberrant myeloid antigen expression is correct name, not biphenotypic leukemia
Molecular / cytogenetics description

  • MYC (8q24.1)
  • TAL1 (1p32)
  • RBTN1 (LMO1) (11p15)
  • RBTN2 (LMO2) (11p13)
  • HOX11 (TLX1) (10q24)
  • HOX11L2 (TLX3) (5q35)
  • LYL1 (19p13)
  • LCK (1p34.3-35)
Molecular / cytogenetics images

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FISH: t(5;14)(q35;q32)

Differential diagnosis
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