Search Database ICD-O-3 Code Lists

Name

Leukemia, NOS (ICD-O-4: 98000/3)

ICD-O-3 Morphology

9800/3: Leukemia, NOS
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

Leukemia, NOS is not included in the WHO 5th edition of Hematolymphoid Tumors. (See Appendix B in the Hematopoietic Manual, Table B23)

Leukemia, NOS is a generic neoplasm description. DCO cases or path report only cases may stay in this classification.

In most cases, NOS histology is only the provisional diagnosis; the physician will run further diagnostic procedures and look for various clinical presentations to identify a more specific leukemia. Further review of the medical record should be done to look for immunophenotyping or genetic testing that would lead to a more specific diagnosis. If the information is not available in the medical record, follow-back with the treating physician.

A more specific diagnosis would include acute leukemia, NOS as well as any specific acute or chronic leukemia. When a more specific diagnosis is identified, the histology should be changed to the more specific neoplasm name and code. See the histology tables for more information on NOS and more specific histologies.

Diagnostic Confirmation

This neoplasm can be diagnosed clinically (diagnostic confirmation codes 5, 6, 8) or histologically WITHOUT positive immunophenotyping or genetics (diagnostic confirmation codes 1, 2, 4)

Module Rule

None

Alternate Names

Aleukemic leukemia, NOS [OBS] (ICD-O-4: 98000/3)
Chronic leukemia, NOS [OBS] (ICD-O-4: 98000/3)
Subacute leukemia, NOS [OBS] (ICD-O-4: 98000/3)

Definition

Leukemia is a cancer of the blood or bone marrow and is characterized by an abnormal proliferation (production by multiplication) of blood cells, usually white blood cells (leukocytes). This is a general term for leukemia (unknown cell type, unknown if acute or chronic).

Definitive Diagnostic Methods

Clinical diagnosis
Histologic confirmation

Genetics Data

None

Immunophenotyping

None

Treatments

None

Transformations to

There are no known transformations

Transformations from

There are no known transformations

Same Primaries

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

C95.9 Leukemia, unspecified
C95.1 Chronic leukemia of unspecified cell type
C95.2 Subacute leukemia of unspecified cell type
C95.7 Other leukemia of unspecified cell type

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

C95.9 Leukemia, unspecified (effective October 01, 2015 - September 30, 2024)
C95.90 Leukemia, unspecified not having achieved remission (effective October 01, 2024)
C95.91 Leukemia, unspecified, in remission (effective October 01, 2024)
C95.92 Leukemia, unspecified, in relapse (effective October 01, 2024)
C95.1 Chronic leukemia of unspecified cell type (effective October 01, 2015 - September 30, 2024)
C95.10 Chronic leukemia of unspecified cell type not having achieved remission (effective October 01, 2024)
C95.10 Chronic leukemia of unspecified cell type, in remission (effective October 01, 2024)
C95.12 Chronic leukemia of unspecified cell type, in relapse (effective October 01, 2024)

Signs and Symptoms

Bone or joint pain
Easy bruising or bleeding
Eczema-like skin rash
Fatigue
Fever
Night sweats
Pain or feeling of fullness below the ribs
Painless lumps
Petechiae
Shortness of breath
Weakness

Diagnostic Exams

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

Progression and Transformation

None

Epidemiology and Mortality

None

Sources

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
Glossary