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Major Categories of Leukemias

If the diagnostic term in the pathology report is not in the list below, be sure to consult your ICD-O manual.

The major categories of leukemias are grouped by cell type—malignancies of lymphocytes and granulocytes or monocytes (also called non-lymphocytic leukemias). Within each category, the behavior of the leukemia is subdivided into acute, subacute, and aleukemia, chronic, and not otherwise specified.

Virtually any blood component can become malignant:

Cell Leukemia Acute Subacute Chronic Aleukemic NOS*
Lymphocyte Lymphocytic leukemia 98353 98003 98233 98203 98203
Monocyte Monocytic leukemia 98913 98603 98603 98603 98603
Stem cell
(primitive white cell)
Stem cell leukemia 98013
Granulocyte
(neutrophil)
Myelocytic/ myelogenous leukemia 98613 98603 98633 98603 98603
Granulocyte
(eosinophil)
Eosinophilic leukemia 99643 99643
Granulocyte
(basophil)
Basophilic leukemia 98703 98703
Megakaryocyte Megakaryocytic leukemia 99103
Erythroblast Erythroleukemia 98403
Plasma cell Plasmacytic leukemia 97333
T-cell Adult T-cell leukemia, HTLV-positive 98273
Unspecified Leukemia, NOS 98013 98003 98003 98003 98003

*NOS—not otherwise specified

The following leukemia morphologies were added to ICD-O-2 effective with Jan. 1, 1998 diagnoses:

ICD-O-2 Code Term
9821/3 Acute lymphoblastic leukemia, L1 type, NOS (*)
  • Acute lymphocytic leukemia, L1 type (*)
  • Acute lymphoid leukemia, L1 type (*)
  • Acute lymphatic leukemia, L1 type (*)
  • Lymphablastic leukemia, L1 type (*)
FAB L1 (*)
9826/3 FAB L3 (*)
9828/3 Acute lymphoblastic leukemia, L2 type, NOS
  • Acute lymphocytic leukemia, L2 type
  • Acute lymphoid leukemia, L2 type
  • Acute lymphatic leukemia, L2 type
  • Lymphablastic leukemia, L2 type
FAB L2
9840/3 FAB M6 (*)
9861/3 Acute myeloid leukemia, NOS (*)
  • Acute myeloblastic leukemia, NOS (*)
  • Acute granulocytic leukemia, NOS (*)
  • Acute myelogenous leukemia, NOS (*)
Acute myelocytic leukemia, NOS (*)
9866/3 FAB M3 (*)
9867/3 Acute myelomonocytic leukemia, NOS (*)
FAB M4 (*)
9871/3 Acute melomonocytic leukemia with eosinophils
FAB M4E
9872/3 Acute myeloid leukemia, minimal differentiation
  • Acute myeloblastic leukemia, minimal differentiation
  • Acute granulocytic leukemia, minimal differentiation
  • Acute myelogenous leukemia, minimal differentiation
  • Acute myelocytic leukemia, minimal differentiation
FAB M0
9873/3 Acute myeloid leukemia, without maturation
  • Acute myeloblastic leukemia, without maturation
  • Acute granulocytic leukemia, without maturation
  • Acute myelogenous leukemia, without maturation
  • Acute myelocytic leukemia, without maturation
FAB M1
9874/3 Acute myeloid leukemia, with maturation
  • Acute myeloblastic leukemia, with maturation
  • Acute granulocytic leukemia, with maturation
  • Acute myelogenous leukemia, with maturation
  • Acute myelocytic leukemia, with maturation
FAB M2
9891/3 FAB M5 (*)
  • FAB M5A (*)
  • FAB M5B (*)
9910/3 Megakaryoblastic leukemia, NOS (C42.1)
  • FAB M7

(*) new term(s) for an existing number