Leukemias 

Leukemias

 

 

Definition:
Leukemias are categorized into chronic and acute forms:

 

Chronic Leukemias:

Chronic lymphocytic leukemias (CLL) 

  • B cell lymphocytic leukemias
    • Small lymphocytic B cell chronic lymphocytic leukemia (CLL, B cell CLL)
    • Mantle cell leukemia
    • Hairy cell leukemia
    • Prolymphocytic B cell leukemia (B cell PLL)
    • Leukemic phase of splenic lymphoma with villous lymphocytes
    • Leukemic phase of marginal zone lymphoma
    • Leukemic phase of lymphoplasmic lymphoma
  • T and NK cell lymphocytic leukemias
    • Large granular lymphocyte (LGL) syndrome (leukemia)
    • Leukemic phase of mycosis fungoides
    • Prolymphocytic T cell leukemia (T cell PLL)
    • Small lymphocytic T cell lymphocytic leukemia (T cell CLL)

Chronic myelocytic leukemias (CML) 

  • Chronic myelocytic leukemia- classified under "myeloproliferative disorders"
  • Chronic myelomonocytic leukemia- classified under "myelodysplastic disorders"

Acute Leukemias:

Acute lymphocytic (lymphoblastic) leukemias (ALL) 

FAB Classification:

  • L1
  • L2
  • L3 (Burkitt's lymphoma/leukemia)

Other variants:

Acute myeloid (myelogenous, myelocytic, myeloblastic, granulocytic, nonlymphoid) leukemia (AML)

FAB Classification: (with modifications)

  • M0 (AML with minimal differentiation, often with a bilineage immunophenotype)
  • M1 (acute myeloblastic leukemia without differentiation)
  • M2 (acute myeloblastic leukemia with differentiation)
    • M2Eo (with eosinophilic differentiation)
  • M3 (acute promyelocytic leukemia, APML)
    • Hypergranular (M3)
    • Hypogranular (microgranular) variant (M3v)
  • M4 (acute myelomonocytic leukemia, Naegeli's acute leukemia, AMML)
    • M4Eo (with eosinophilic differentiation)
  • M5 (acute monocytic leukemia, Schilling's acute leukemia, AMoL)
    • M5a (undifferentiated)
    • M5b (AMoL with differentiation)
  • M6 (acute erythroid leukemia, erythroleukemia, erythemic myelosis, diGuglielmo's syndrome)
  • M7 (acute megakaryocytic leukemia)
    • micromegakaryoblastic variant
    • megakaryoblastic variant

WHO Classification:

In addition to the FAB designations and the other variants, the WHO classification has added subtypes that have emerged as distinct entities based on cytogenetic abnormalities and other clinical and laboratory features.

  • AML with recurrent cytogenetic abnormalities
    • AML with the t(8;21)- most are M2 AMLs
    • AML with the INV(16) or t(16;16)- most are M4 AMLs with abnormal eosinophils
    • AML with the t(15;17)- M3 AML
    • AML with 11q23 abnormalities- usually has monocytic features
  • AML with multilineage dysplasia
    • AML emerging from a myelodysplastic or myeloproliferative disorder
    • DeNovo AML with multilineage dysplasia
  • M6 AML (acute erythroid leukemia)
    • M6a (mixed erythroid and myeloid)
    • M6b (pure erythroid leukemia)
  • AML, therapy-related (secondary acute leukemias)
    • Includes those associated with exposure to alkylating agents, topoisomerase type II inhibitors, other drugs, and radiation.

 

General References:

  • Jaffe ES, Harris NL, Stein H, Vardiman JW (Eds). World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of Haematopoietic and Lymphoid Tissues. IRAC Press: Lyon 2001
  • Bennett JM, Catovsky D, Daniel MT, et al: Proposed revised criteria for the classification of acute myeloid leukemia: A report of the French-American-British Cooperative Group. Am Intern Med 103:620, 1985
  • Bennett JM, Catovsky D, Daniel MT, et al: French-American-British (FAB) Cooperative Group: The morphological classification of acute lymphoblastic leukemia- concordance among observers and clinical correlations. Br J Haematol 47:553, 1981
  • Bennett JM, Catovsky D, Daniel MT, et al: Proposals for the classification of chronic (mature) B and T lymphoid leukemias. J Clin Pathol. 42:567, 1989

 

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Charles  E.  Hess,  M.D.,FACP    [more information]
Professor of Internal Medicine
Department: Medicine
Division: Hematology/Oncology