Name

Acute monoblastic and monocytic leukemia

ICD-O-1 Morphology

9891/3: Acute monocytic leukemia
Effective 1978 - 1991

ICD-O-2 Morphology

9891/3: Acute monocytic leukemia
Effective 1992 - 2000

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)

Grade

Not Applicable

Module Rule

None

Alternate Names

Acute monoblastic leukemia
Acute monoblastic leukemia and acute monocytic leukemia
Acute monoblastic leukemia, M5a
Acute monocytic leukemia
Acute monocytic leukemia, M5b
FAB M5 (includes all variants)
Monoblastic leukemia, NOS

Definition

Acute monoblastic and monocytic leukemia are myeloid leukemias in which the peripheral blood or bone marrow has greater than or equal to 20% blasts (including promonocytes) and in which greater than or equal to 80% of the leukemic cells are of monocytic lineage, including monoblasts, promonocytes, and monocytes; a minor neutrophil component (< 20%) may be present. Acute monoblastic leukemia and acute monocytic leukemia are distinguished by the relative proportions of monoblasts and promonocytes.

In acute monoblastic leukemia, most (greater than or equal to 80%) of the monocytic cells are monoblasts. In acute monocytic leukemia, most of the monocytic cells are promonocytes or monocytes.

Abstractor Notes

If the leukemia occurs before or simultaneously with Myeloid Sarcoma (9930/3), see M3 and Module 5: PH10.

Definitive Diagnostic Methods

Bone marrow biopsy
Flow cytometry
Genetic testing
Histologic confirmation
Immunophenotyping

Genetics Data

t(8;16)(p11.2;p13.3)

Immunophenotyping

CD4 expression
CD11b expression
CD11c expression
CD13 expression
CD14 expression
CD15 expression
CD33 bright expression
CD34 positive
CD36 bright expression
CD64 bright expression
CD65 expression
CD68 expression
HLA-DR positive
Lysozyme expression
KIT (CD117) expression
MPO expression

Treatments

Chemotherapy
Hematologic Transplant and/or Endocrine Procedures

Transformations to

None

Corresponding ICD-9 Codes

206.0 Acute monocytic leukemia

Corresponding ICD-10 Codes

C93.0 Acute monocytic leukemia

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

C93.0 Acute monoblastic/monocytic leukemia (effective October 01, 2015)

Signs and Symptoms

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

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

Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J (Eds):
WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (Revised 4th edition)
IARC: Lyon 2017
Section: Acute myeloid leukemia and related precursor neoplasms
Pages: 160-161

International Classification of Diseases for Oncology, Third Edition, First Revision. Geneva: World Health Organization, 2013.
Section: ICD-O-3.1 (2011) Morphological Codes
Pages: http://codes.iarc.fr/codegroup/2

National Cancer Institute
Section: General Information About Acute Myeloid Leukemia
Pages: https://www.cancer.gov/types/leukemia/hp/adult-aml-treatment-pdq
Glossary