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

ICD-O-2 Morphology
9715/3: Mucosal-associated lymphoid tissue lymphoma (MALT)
Effective 1995 - 2000
ICD-O-3 Morphology
9699/3: Marginal zone B-cell lymphoma, NOS
Effective 2001 and later
for cases diagnosed 1995 and later
Primary Site(s)
See Module 7
Note: Do not code primary site to spleen (C422). Most common sites of involvement: GI tract (stomach most common), salivary gland, lung, head and neck, ocular adnexa, skin, thyroid, and breast

Not Applicable
Module Rule
Alternate Names
Marginal zone lymphoma, NOS
Monocytoid B-cell lymphoma
Nodal marginal zone B-cell lymphoma
Nodal marginal zone lymphoma
Nodal MZL
Parafollicular B-cell lymphoma
Pediatric nodal marginal zone lymphoma
Skin-associated lymphoid tissue lymphoma
Extranodal involving MALT tissue, nodal without evidence of MALT or splenic disease. Lymphoma derived from B cells present in marginal zone, outer part of mantle zone of B-cell follicles. Mantle zone of follicles more developed in lymphoid organs facing high influx of antigens, representing mucosal immune system.
Abstractor Notes
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)

The majority of patients present with stage I or II disease. A minority have bone marrow (BM) involvement. The frequency of BM involvement is lower in gastric cases and higher in MALT lymphomas arising in the lung and ocular adnexa.

Multiple extranodal sites may be involved in up to 25% of extragastric cases at the time of presentation. MALT lymphomas may have involvement of multiple extranodal sites, particularly of paired organs (e.g. salivary glands) or organ systems (e.g. gastrointestinal tract, skin).

The differential diagnosis includes the history of reactive inflammatory process that typically precedes the lymphoma include:
1. Heliobacter pylori
2. Gastritis
3. Lymphoepithelial sialadenitis
4. Hashimoto thyroiditis
5. Other small B-cell lymphomas (follicular lymphoma, mantle cell lymphoma, small lymphocytic lymphoma).

The demonstration of immunoglobulin light chain restriction is important in the differential diagnosis.

There are two variants of MALT, both of which are coded to 9699/3:

1. Nodal marginal zone lymphoma (NMZL) usually presents with involvement of peripheral lymph nodes. Occasionally the bone marrow and peripheral blood are involved. NMZL is a primary B-cell neoplasm that morphologically resembles lymph nodes involved by marginal zone lymphoma of extranodal or splenic types, but without evidence of extranodal or splenic disease.

2. Pediatric nodal marginal zone lymphoma in the pediatric age group has distinct clinical and morphological characteristics. It presents predominantly in males and with localized (90% are Stage I) disease, mainly in the head and neck lymph nodes. Studies for clonal rearrangements of IGH@chain are necessary to help distinguish pediatric NMZL from reactive conditions. The prognosis for pediatric NMZL is excellent with very low relapse rates and long survival after conservative treatment.
Definitive Diagnostic Methods
Genetic testing
Histologic confirmation
Genetics Data
Immunoglobulin heavy and light chain genes rearranged
Mutated VH3
Mutated VH4
Production of a chimeric protein (AP12-MALTq,FOXP1) respectively
Translocations (q21; q21)
Translocations t(1;14)(p22;q32)
Translocations t(3;14)(p14.1;q32)
Translocations t(14;18)(q32;q21)
Trisomy 3, 18
CD43 coexpression
Cyclin D1-
IgM expression
Tumor cells may express IgA
Tumor cells may express IgG
Other RX (Antibiotics)
Transformations from
Corresponding ICD-9 Codes
200.3 Marginal zone lymphoma
Corresponding ICD-10 Codes
C83.0 Diffuse non-Hodgkin's lymphoma, small cell (diffuse)
Corresponding ICD-10-CM Codes (U.S. only)
C88.4 Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue [MALT lymphoma] (effective October 01, 2015)
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 rash or itchy skin
Weight loss (for no known reason)
Diagnostic Exams
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