Search Database ICD-O-3 Code Lists

Name

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)

ICD-O-3 Morphology

9699/3: Marginal zone B-cell lymphoma, NOS
Effective 2001 and later

Reportable

for cases diagnosed 1978 and later

Primary Site(s)

See Module 7
Note: Do not code primary site to spleen (C422).

Common sites are the stomach, ocular adnexa, salivary gland, skin, lung, breast, thyroid, and thymus. Others include the upper aerodigestive tract, small and large intestines, hepatobiliary system, pancreas, dura and brain, urogenital tract, female genital tract, and soft tissues.
Common metastatic sites: bone marrow

See abstractor notes

Coding Manual: Hematopoietic Coding Manual (PDF)

Abstractor Notes

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is part of the Mature B-cell neoplasms lineage table in the WHO 5th edition of Hematolymphoid Tumors. (See Appendix B in the Hematopoietic Manual, Table B15)

Do not code the primary site to spleen for this histology. If the primary site is spleen, code the histology to 9689/3 (splenic marginal zone lymphoma).

Extranodal marginal zone B-cell lymphoma can occur in almost any anatomical site. The disease is usually diagnosed when it is localized. Gastric EMZL is linked to chronic Helicobacter pylori infection.

Primary cutaneous marginal zone lymphoma is most commonly seen in the trunk and arms.
* Subtypes include Heavy chain class-switched form (IgG+, IgA+, or IgE+), non–class-switched form (IgM+)

Nodal marginal zone lymphoma involves single or multiple lymph nodes, most frequently in the head and neck, often disseminates to the bone marrow.

Pediatric marginal zone lymphoma (PNMZL) involves the lymph nodes of the head and neck region (cervical, submandibular, supraclavicular).
* Treatment includes complete resection, followed by watchful waiting. Systemic therapy reserved for patients with advanced disease.

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.

Module Rule

None

Alternate Names

Bronchus-associated lymphoid tissue (BALT) lymphoma
Extranodal marginal zone lymphoma
Marginal zone B-cell lymphoma, NOS
Marginal zone lymphoma, NOS
Monocytoid B-cell lymphoma
Mucosal-associated lymphoid tissue (MALT) lymphoma
Pediatric nodal marginal zone lymphoma (PNMZL)
Primary choroidal lymphoma (C693)
Primary cutaneous marginal zone lymphoma
Primary cutaneous marginal zone lymphoma, heavy chain class switched form (IgG+, IgA+, or IgE+)
Primary cutaneous marginal zone lymphoma, heavy chain non-class switchede form (IgM+)
Skin-associated lymphoid tissue (SALT) lymphoma

Definition

Four major types of marginal zone lymphoma are now collected under code 9699/3

1. Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (EMZL) is an indolent primary extranodal B-cell lymphoma with cytological and architectural features reminiscent of Peyer patch lymphoid tissue, the prototypical mucosa-associated lymphoid tissue (MALT). EMZL typically arises from marginal zone B cells of acquired MALT and is often associated with an underlying chronic inflammatory disorder. (WHO 5th edition)

2. Primary cutaneous marginal zone lymphoma (PCMZL) is an indolent cutaneous B-cell lymphoma composed of neoplastic small B cells, plasma cells, and a variable number of reactive T cells. (WHO 5th edition)

3. Nodal marginal zone lymphoma (NMZL) is a primary nodal lymphoma of small, mature B cells derived from marginal zone B cells, without involvement of extranodal sites or the spleen. (WHO 5th edition)

4. Pediatric nodal marginal zone lymphoma (PNMZL) is a primary nodal mature B-cell neoplasm, mostly occurring in the head and neck region of adolescent boys. PNMZL shares the interfollicular expansion of clonal marginal zone B cells with usual nodal marginal zone lymphoma (NMZL). Nevertheless, the specific clinical and histomorphological features differ from those of the adult counterpart. (WHO 5th edition)

Definitive Diagnostic Methods

Cytogenetics
Clinical diagnosis
Genetic testing
Histologic confirmation
Immunohistochemistry
Immunophenotyping

Genetics Data

Absence of 7q31-32 and 13q14 deletions (NMZL)
Biased usage of IG genes, expressing autoreactive antigen B-cell receptor (EMZL)
FAS mutations affecting the death domain of the apoptosis-regulating FAS (CD95) protein (PCMZL)
Gains of chromosomes 2p, 6p, trisomy 3, 12, 18 (NMZL)
Somatic IGHV mutations (NMZL)

Immunophenotyping

BCL2+ (expression/positive) (PCMZL)
BCL6- (no expression/negative) (EMZL, PCMZL)
CD5- (no expression/negative) (EMZL, PCMZL)
CD10- (no expression/negative) (PCMZL)
CD19+ (expression/positive) (NMZL)
CD20+ (expression/positive) (EMZL, NMZL)
CD23- (no expression/negative) (EMZL)
CD79a+ (expression/positive) (NMZL)
Cyclin D1- (no expression/negative) (EMZL, PCMZL)
Monoclonal rearrangement of immunoglobulin heavy and/or light chain genes (IGH, IGK) (PNMZL)
PAX5+ (expression/positive) (NMZL)
t(11;18)(q21;q21)/BIRC3::MALT1 fusion (EMZL)

Treatments

Chemotherapy
Other therapy
Radiation therapy

Transformations to

Transformations from

None

Same Primaries

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

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

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

C83.0_ Small cell B-cell lymphoma (nodal marginal zone lymphoma) (effective October 01, 2015)
C83.0A Small cell B-cell lymphoma (nodal marginal zone lymphoma), in remission (effective October 01, 2024)
C88.4 Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue [MALT lymphoma] (effective October 01, 2015 - September 30, 2024)
C88.40 Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue [MALT lymphoma] not having achieved remission (effective October 01, 2024)
C88.41 Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue [MALT lymphoma], in remission (effective October 01, 2024)

Signs and Symptoms

Drenching night sweats
Fatigue
Fever (for no known reason)
Pain in the chest, abdomen, or bones (for no known reason)
Painless swelling in the lymph nodes
Peripheral lymphadenopathy
Skin rash or itchy skin
Weight loss (for no known reason)

Diagnostic Exams

Blood chemistry studies
Bone marrow aspiration and biopsy
CT (CAT) scan
Cytogenetic analysis
Flow cytometry
Immunohistochemistry
Immunophenotyping
Laparoscopy (rarely performed)
Laparotomy (rarely performed)
Lymph node biopsy
PET (positron emission tomography) scan

Progression and Transformation

Recurrences may occur after many years and may involve

Epidemiology and Mortality

Age: 61 years median age
Country: higher incidence in north-east Italy
Incidence: 7-8% of all B-cell lymphoma and up to 50% of primary gastric lymphomas
Sex: slight female predominance

Sources

WHO Classification of Tumours Editorial Board. Haematolymphoid tumours. Lyon (France): International Agency for Research on Cancer; 2024. (WHO classification of tumours series, 5th ed.; vol. 11). https://publications.iarc.who.int/637.
Section: Marginal Zone Lymphoma
Pages: Part B: 401-419

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

PDQ® Adult Treatment Editorial Board. PDQ Indolent B-Cell Non-Hodgkin Lymphoma Treatment. Bethesda, MD: National Cancer Institute. Updated <02/18/2025>. Available at: https://www.cancer.gov/types/lymphoma/hp/indolent-b-cell-lymphoma-treatment-pdq. Accessed <03/04/2025>. [PMID: 37437080]
Section: Indolent B-Cell Non-Hodgkin Lymphoma Treatment (PDQ®)–Health Professional Version
Pages: https://www.cancer.gov/types/lymphoma/hp/adult-nhl-treatment-pdq
Glossary