Non-Hodgkin lymphoma, NOS

ICD-O-1 Morphology
9591/3: Malignant lymphoma, non-Hodgkin, NOS
Effective 1978 - 1991
ICD-O-2 Morphology
9591/3: Malignant lymphoma, non-Hodgkin, NOS
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

Not Applicable
Module Rule
Alternate Names
Hairy cell leukemia-variant/prolymphocytic variant of hairy cell leukemia
Lymphomatosis cerebri
Lymphosarcoma, diffuse [OBS]
Lymphosarcoma, NOS [OBS]
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]
Pleomorphic variant of HCL
Reticulosarcoma, diffuse [OBS]
Reticulosarcoma, NOS [OBS]
Reticulum cell sarcoma, diffuse [OBS]
Reticulum cell sarcoma, NOS [OBS]
SMZL diffuse variant
Splenic B-cell lymphoma/leukemia, unclassifiable
Splenic diffuse red pulp small B-cell lymphoma
Splenic marginal zone diffuse variant
Thrombocytic variant of hairy-cell leukemia
Thrombocytic variant of HCL
Non-Hodgkin lymphoma not further classified. This is not a commonly used pathology term.

See abstractor notes for definitions of splenic B-cell lymphoma/leukemia, unclassifiable and the two most common types.
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.

WHO assigns the non-Hodgkin lymphoma, NOS code to a number of neoplasms. All of these assigned histology code 9591/3:
1. Splenic B-cell lymphoma/leukemia, unclassifiable, a term that describes a number of variably well-defined entities involving the spleen that do not fall into any of the other types of B-cell lymphoid neoplasms. When using this code to describe splenic B-cell lymphoma/leukemia do the necessary text documentation to differentiate this disease from the non-Hodgkin, NOS.

2. Splenic diffuse red pulp small B-cell lymphoma (rare disorder). Diagnosed at clinical stage IV with spleen, BM and PB involvement. Diffuse involvement of the red pulp of the spleen.

3. Hairy cell leukemia-variant. Also has BM and PB involvement.

4. Thrombocytic variant of hairy cell leukemia/hairy cell leukemia variant (Do not confuse with hairy cell leukemia. This neoplasm must be described as a VARIANT.) HCL-v accounts for about 10% of hairy cell leukemia cases. Spleen, BM and PB are involved. Hepatomegaly and lymphadenopathy is uncommon. Involvement of other solid tissue is rare. For hairy cell leukemia variant, code primary site to C421 with histology code 9591/3.

5. Lymphomatosis cerebri is a rare primary central nervous system lymphoma (PCNSL). This disease presents as a diffuse, infiltrating process without the formation of a mass. Radiographs show diffuse white matter involvement without enhancement.
Definitive Diagnostic Methods
Bone marrow biopsy
Clinical diagnosis
Histologic confirmation
Genetics Data
Annexin A1-
CD11c+ (HCL-v)
CD11c- (splenic red pulp disease)
CD103+ (HCL-v)
CD123- (splenic red pulp disease)
DBA.44 (CD72)+
Bone marrow transplant
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's lymphoma, unspecified type
Corresponding ICD-10-CM Codes (U.S. only)
C85.9 Non-Hodgkin's lymphoma, unspecified (effective October 01, 2015)
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)
Progression and Transformation
Epidemiology and Mortality