Splenic marginal zone lymphoma

ICD-O-3 Morphology

9689/3: Splenic marginal zone B-cell lymphoma
Effective 2001 and later


for cases diagnosed 2001 and later

Primary Site(s)

Primary site must be spleen (C422)

Abstractor Notes

Splenomegaly is seen in almost all patients, commonly without lymphadenopathy. The bone marrow is frequently positive. Nodal and extranodal involvement are rare.

The lack of CD5 expression is helpful in the discrimination between SMZL and chronic lymphocytic leukemia/small lymphocytic lymphoma, and the lack of CD10 expression argues against follicular lymphoma. Mantle cell lymphoma is excluded due to the lack of CD5 and cyclin-D1 expression.

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

Splenic B-cell marginal zone lymphoma
Splenic lymphoma with circulating villous lymphocytes (SLVL)
Splenic lymphoma with villous lymphocytes
Splenic marginal zone lymphoma diffuse variant
Splenic marginal zone B-cell lymphoma (SMZL)
Splenic marginal zone lymphoma (MZL), NOS


Splenic marginal zone lymphoma (SMZL) is a B-cell neoplasm composed of small lymphocytes that surround and replace the splenic white pulp germinal centers, efface the follicle mantle, and merge with a peripheral (marginal) zone of larger cells, including scattered transformed blasts; both small and larger cells infiltrate the red pulp. Splenic hilar lymph nodes and bone marrow are often involved, lymphoma cells are frequently found in the peripheral blood as villous lymphocytes.

Definitive Diagnostic Methods

Genetic testing
Histologic confirmation

Genetics Data

Allelic loss of chromosome 7q31-32
Dysregulation of CDK6 gene at 7q21
Immunoglobulin heavy and light chain rearrangement


Annexin A1- (no expression/negative)
CD5- (no expression/negative)
CD10- (no expression/negative)
CD20+ (expression/positive)
CD23- (no expression/negative)
CD43- (no expression/negative)
CD79a+ (expression/positive)
CD103- (no expression/negative)
Cyclin D1- (no expression/negative)
Ki-67 staining shows distinctive targetoid pattern
LEF1- (no expression/negative)
Surface IgD
Surface IgM



Transformations from


Corresponding ICD-9 Codes

200.3 Marginal zone lymphoma

Corresponding ICD-10 Codes

C83.0 Non-Hodgkin lymphoma small cell (diffuse)

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

C83.0 Small cell B-cell lymphoma (effective October 01, 2015)

Signs and Symptoms

Drenching night sweats
Fever (for no known reason)
Pain in the chest, abdomen, or bones (for no known reason)
Painless swelling in the lymph nodes
Skin rashes or itchy skin
Thrombocytopenia (autoimmune)
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
PET (positron emission tomography) scan

Progression and Transformation

Transformation to large B-cell lymphoma may occur

Epidemiology and Mortality

Age: mostly 50 years and older
Incidence: 2% of lymphoid neoplasms
Sex: no male or female predominance
Survival: long term survival for patients who have splenectomy


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: 223-225

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)