Non-Hodgkin lymphoma, NOS

ICD-O-1 Morphology

9591/3: Malignant lymphoma, non-Hodgkin, NOS
9610/3: Lymphosarcoma, NOS
9630/3: Malignant lymphoma, lymphocytic, poorly differentiated, NOS
9631/3: Prolymphocytic lymphosarcoma
9640/3: Reticulosarcoma, NOS
9641/3: Reticulosarcoma, pleomorphic cell type
9642/3: Reticulosarcoma, nodular
Effective 1978 - 1991

ICD-O-2 Morphology

9591/3: Malignant lymphoma, non-Hodgkin, NOS
9592/3: Lymphosarcoma, NOS
9593/3: Reticulosarcoma, NOS
9595/3: Malignant lymphoma, diffuse, NOS
9686/3: Malignant lymphoma, small cell, noncleaved, diffuse
9694/3: Malignant lymphoma, lymphocytic, intermediate differentiation, nodular
Effective 1992 - 2000

ICD-O-3 Morphology

9591/3: Malignant lymphoma, non-Hodgkin, NOS
Effective 2001 and later


for cases diagnosed 1978 and later

Primary Site(s)

See Abstractor Notes and Module 7

Abstractor Notes

This code is defined as non-Hodgkin lymphoma, NOS in the ICD-O-3. If you are using the code for non-Hodgkin, NOS, the "NOS" histology is a generic disease description. DCO cases and path-report only cases may remain in this classification.

Most commonly, however, a 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 done to look for the tests listed as definitive diagnosis.

When a more specific diagnosis is identified, change the histology to the more definitive term and code. More specific diseases would be any of the specific non-Hodgkin lymphoma histologies.

Diagnostic Confirmation

This histology can be determined by positive histology (including peripheral blood) with or without genetics and/or immunophenotyping. Review the Definitive Diagnostic Methods, Immunophenotyping and Genetics Data sections below, and the instructions in the Hematopoietic Manual for further guidance on assigning Diagnostic confirmation.


Not Applicable

Module Rule


Alternate Names

B-cell lymphoma, NOS
Hairy cell leukemia-variant (thrombocytic) (HCL-v)
Lymphocytic lymphoma simulating hairy cell leukemia
Lymphomatosis cerebri
Lymphosarcoma, diffuse [OBS]
Lymphosarcoma, NOS [OBS]
Malignant lymphoma, diffuse, NOS
Malignant lymphoma, lymphocytic, intermediate differentiation, nodular [OBS]
Malignant lymphoma, lymphocytic, poorly differentiated, diffuse [OBS]
Malignant lymphoma, non-cleaved cell, NOS
Malignant lymphoma, non-Hodgkin, NOS
Malignant lymphoma, small cell, noncleaved, diffuse [OBS]
Malignant lymphoma, small cleaved cell, NOS [OBS]
Mature B-cell lymphoma/leukemia, NOS (see 9811/3 for immature)
Non-Hodgkin Lymphoma (NHL), NOS
Pleomorphic variant of hairy cell leukemia
Pleomorphic variant of HCL
Prolymphocytic variant of hairy cell leukemia
Reticulosarcoma, diffuse [OBS]
Reticulosarcoma, NOS [OBS]
Reticulum cell sarcoma, diffuse [OBS]
Reticulum cell sarcoma, NOS [OBS]
Splenic B-cell lymphoma/leukemia, unclassifiable
Splenic diffuse red pulp small B-cell lymphoma


Non-Hodgkin lymphoma not further classified. This is not a commonly used pathology term.

There are two main variants for NHL, NOS. Tese are assigned histology code 9591/3.

1) Splenic diffuse red pulp small B-cell lymphoma (SDRPL) is an uncommon lymphoma with a diffuse pattern of involvement of the splenic red pulp by small monomorphous B lymphocytes. The neoplasm also involves bone marrow sinusoids and peripheral blood.

2) Hairy cell leukemia variant (HCL-v) encompasses cases of B-cell chronic lymphoproliferative disorders that resemble classic HCL but exhibit variant cytological and hematological features such as leukocytosis, presence of monocytes, cells with prominent nucleoli, cells with blastic or convoluted nuclei, and/or absence of circumferential shaggy contours. It is also called prolymphocytic variant of hairy cell leukemia.

Definitive Diagnostic Methods

Bone marrow biopsy
Clinical diagnosis
Histologic confirmation

Genetics Data



Annexin A1- (no expression/negative)
CD5+ (expression/positive)
CD10- (no expression/negative)
CD11c (HCL-v)+ (expression/positive)
CD11c (splenic red pulp disease)- (no expression/negative)
CD20+ (expression/positive)
CD23- (no expression/negative)
CD25- (no expression/negative)
CD103 (HCL-v)+ (expression/positive)
CD103- (no expression/negative)
CD123 (splenic red pulp disease)- (no expression/negative)
DBA.44 (CD72)+ (expression/positive)
IgD- (no expression/negative)
IgG+ (expression/positive)


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
200.0 Reticulosarcoma

Corresponding ICD-10 Codes

C85.1 B-cell lymphoma, unspecified
C85.0 Lymphosarcoma

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

C85.1 Unspecified B-cell lymphoma (effective October 01, 2015)

Signs and Symptoms

Drenching night sweats
Fever (for no known reason)
Massive splenomegaly (hairy cell leukemia variant type)
Pain in the chest, abdomen, or bones (for no known reason)
Painless swelling in the lymph nodes
Skin rash or itchy skin
Weight loss (for no known reason)

Diagnostic Exams

Blood chemistry studies
CT (CAT) scan
Cytogenetic analysis
Flow cytometry
Laparoscopy (rarely performed)
Laparotomy (rarely performed)
Lymph node biopsy
Peripheral blood smear
PET (positron emission tomography) scan

Progression and Transformation


Epidemiology and Mortality



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: Mature B-cell neoplasms
Pages: 229-231

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: General Information About Adult Non-Hodgkin Lymphoma (NHL)