Search Database ICD-O-3 Code Lists

Name

Acute monocytic leukemia (ICD-O-4: 98910/3)

ICD-O-3 Morphology

9891/3: Acute monocytic leukemia
Effective 2001 and later

Reportable

for cases diagnosed 1978 and later

Primary Site(s)

C421
Primary site must be bone marrow (C421)

Coding Manual: Hematopoietic Coding Manual (PDF)

Abstractor Notes

Acute monocytic leukemia is part of the Acute myeloid leukemia (AML) lineage table in the WHO 5th edition of Hematolymphoid Tumors. (See Appendix B in the Hematopoietic Manual, Table B6)

These leukemias predominantly involve the blood and bone marrow. Extramedullary disease is common, particularly involving the gingiva, skin, and CNS.

If this leukemia and myeloid sarcoma (9930/3) occur during the same clinical workup, this is one primary, the leukemia.

If the myeloid sarcoma occurs after the diagnosis of the leukemia, that is a manifestation of the leukemia and is the same primary.

See Multiple Primary Rule M3

Diagnostic Confirmation

Assign code 1 for histological confirmation WITH or WITHOUT positive immunophenotyping

Module Rule

None

Alternate Names

Acute monoblastic leukemia (ICD-O-4: 98910/3)
Acute monoblastic and monocytic leukemia (ICD-O-4: 98910/3)
FAB M5 (ICD-O-4: 98910/3)
Monoblastic leukemia, NOS (ICD-O-4: 98910/3)

Definition

Acute monocytic leukemia is an acute myeloid leukemia (AML) with monocytic differentiation that lacks defining genetic abnormalities. (WHO 5th edition)

Definitive Diagnostic Methods

Histologic confirmation
Immunohistochemistry
Immunophenotyping

Genetics Data

Immunophenotyping

CD4, CD11c, CD14, CD64, CD68, CD117, CD163, IRF8, lysozyme, NSE

Treatments

Chemotherapy
Hematologic Transplant and/or Endocrine Procedures

Transformations to

None

Transformations from

Same Primaries

Corresponding ICD-10 Codes (Cause of Death codes only)

C93.0 Acute monocytic leukemia

Corresponding ICD-10-CM Codes (U.S. only)

C93.0 Acute monoblastic/monocytic leukemia (effective October 01, 2015 - September 30, 2024)
C93.00 Acute monoblastic/monocytic leukemia not having achieved remission (effective October 01, 2024)
C93.01 Acute monoblastic/monocytic leukemia, in remission (effective October 01, 2024)
C93.02 Acute monoblastic/monocytic leukemia, in relapse (effective October 01, 2024)

Signs and Symptoms

Bleeding disorders
Central nervous involvement common
Cutaneous and gingival infiltration
Easy bruising and bleeding
Extramedullary masses
Fatigue
Fever
Petechiae
Shortness of breath
Weakness
Weight loss or loss of appetite

Diagnostic Exams

Bone marrow aspiration and biopsy
CT (CAT) scan
Cytogenetic analysis
Flow cytometry
Immunophenotyping
Lumbar puncture
Peripheral blood smear
Physical exam and history
Molecular analysis

Progression and Transformation

None

Epidemiology and Mortality

Age (acute monoblastic leukemia): most common in young
Age (acute monocytic leukemia): 49 years median age
Incidence: <5% of all cases of AML
Sex: female predominance

Sources

WHO Classification of Tumours Editorial Board. Haematolymphoid tumours. Lyon (France): International Agency for Research on Cancer; 2024. (WHO classification of tumours series, 5th ed.; vol. 11). https://publications.iarc.who.int/637.
Section: Acute myeloid leukemia
Pages: Part A: 157-159

International Classification of Diseases for Oncology, 3rd edition (including revisions). Geneva: World Health Organization, 2001, 2011, 2020.
Section: ICD-O-3.2 (2020) Morphological Codes
Pages: http://www.iacr.com.fr/index.php?option=com_content&view=category&layout=blog&id=100&Itemid=577

PDQ® Adult Treatment Editorial Board. PDQ Acute Myeloid Leukemia Treatment. Bethesda, MD: National Cancer Institute. Updated <03/06/2024>. Available at: https://www.cancer.gov/types/leukemia/hp/adult-aml-treatment-pdq. Accessed <02/06/2025>. [PMID: 26389432]
Section: Acute Myeloid Leukemia Treatment (PDQ®)–Health Professional Version
Pages: https://www.cancer.gov/types/leukemia/hp/adult-aml-treatment-pdq
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