Malignant lymphoma, NOS

ICD-O-1 Morphology

9590/3: Malignant lymphoma, NOS
9601/3: Malignant lymphoma, stem cell type
9603/3: Stem cell lymphoma
Effective 1978 - 1991

ICD-O-2 Morphology

9590/3: Malignant lymphoma, NOS
9594/3: Microglioma
Effective 1992 - 2000

ICD-O-3 Morphology

9590/3: Malignant lymphoma, NOS
Effective 2001 and later


for cases diagnosed 1978 and later

Primary Site(s)

See Abstractor Notes and Module 7

Abstractor Notes

This NOS histology is a generic disease description. DCO cases or path report only cases may stay in this classification. In most cases, an NOS histology is only the working diagnosis; the physician will run further diagnostic procedures and look for various clinical presentations to identify a more specific disease.

Further review of the medical record should be performed to look for the tests listed as definitive diagnosis. When a more specific diagnosis is identified, the histology should be changed to the more specific neoplasm name and code.

For 9590/3 malignant lymphoma, NOS, non-Hodgkin lymphoma, classical Hodgkin lymphoma, and any specific Hodgkin and non-Hodgkin lymphomas would be a more specific histology.

See the histology tables (Appendix B of the Hematopoietic manual) for more information on NOS and more specific histologies.

Diagnostic Confirmation

This is a histology for which the Definitive Diagnostic Method does not include Genetics Data or Immunophenotyping, thus Diagnostic Confirmation should never be 3. If genetics and/or immunophenotyping are available, re-review to see if a more specific neoplasm can be coded.


Not Applicable

Module Rule


Alternate Names

Lymphoma, NOS
Microglioma ( C71_) [OBS]


General term for a group of cancers that originate in the lymphatic system. Unable to determine if Hodgkin or non-Hodgkin type. This is not a commonly used pathology term.

Definitive Diagnostic Methods

Clinical diagnosis
Histologic confirmation

Genetics Data





Hematologic Transplant and/or Endocrine Procedures
Hormone therapy
Radiation therapy

Transformations to

There are no known transformations

Transformations from

There are no known transformations

Same Primaries

Corresponding ICD-9 Codes

202.8 Other lymphoma

Corresponding ICD-10 Codes

C85.9 Non-Hodgkin lymphoma, unspecified type

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

C85.9 Non-Hodgkin lymphoma, unspecified (effective October 01, 2015)
C85.8 Other specified types of non-Hodgkin lymphoma (effective October 01, 2015)

Signs and Symptoms


Diagnostic Exams


Progression and Transformation


Epidemiology and Mortality



International Classification of Diseases for Oncology, Third Edition, Second Revision. Geneva: World Health Organization, 2020
Section: ICD-O-3.2 (2020) Morphological Codes

National Cancer Institute
Section: Lymphoma