Mucosa-associated lymphoid tissue (MALT) lymphoma, also called extranodal marginal zone B-cell lymphoma, is a type of low-grade extranodal lymphoma.
MALT lymphoma represents ~7.5% of non-Hodgkin lymphomas. The average age of presentation is 60 years with a slight female predominance 1. Prevalence is estimated at 2 per 100,000 7.
Clinical presentation depends on the affected organ. B-type symptoms are rare 1,3.
MALT lymphomas arise in epithelial tissues where lymphoid cells are not usually found. Chronic infection/inflammation has been implicated in the pathogenesis, for example, Helicobacter pylori infection with gastric MALT lymphoma, and Sjogren syndrome with salivary gland MALT lymphoma 1,3. Less than 10% transform from low-grade to high-grade disease 4.
MALT lymphoma can localise throughout the entire body 1,4:
- stomach: most common; 33-50% (see: gastric lymphoma)
- associated with H. pylori infection in 90% of cases 7
- intestine: ~5%
- possible association with Coeliac disease 6
- salivary glands
- associated with Sjogren syndrome
- associated with Hashimoto thyroiditis 5
- orbit (see: orbital lymphoma)
- lung and upper airways (see: BALT lymphoma)
Metastases to other sites including lymph nodes and bone marrow are not uncommon.
Imaging features of MALT lymphoma depend on which organ is affected.
Treatment and prognosis
MALT lymphoma is considered an indolent disease with a good prognosis. Treatment should be tailored to the affected organ and may consist of surgery, chemotherapy and/or radiation therapy 2. Antibiotics are used to treat gastric MALT lymphoma; there is a lack of evidence for its use in treating non-gastric MALT lymphoma 7.
- 1. Lymphoma: Pathology, Diagnosis, and Treatment (Cambridge Medicine). Cambridge University Press. ISBN:1107010594. Read it at Google Books - Find it at Amazon
- 2. Grossbard ML. Malignant lymphomas. pmph usa. ISBN:1550091522. Read it at Google Books - Find it at Amazon
- 3. Modern Hematology: Biology and Clinical Management. Humana Press. ISBN:1588295575. Read it at Google Books - Find it at Amazon
- 4. Radiological Imaging in Hematological Malignancies. Springer. ISBN:3540439994. Read it at Google Books - Find it at Amazon
- 5. Troch M, Woehrer S, Streubel B et-al. Chronic autoimmune thyroiditis (Hashimoto's thyroiditis) in patients with MALT lymphoma. Ann. Oncol. 2008;19 (7): 1336-9. doi:10.1093/annonc/mdn049 - Pubmed citation
- 6. Smedby KE, Akerman M, Hildebrand H et-al. Malignant lymphomas in coeliac disease: evidence of increased risks for lymphoma types other than enteropathy-type T cell lymphoma. Gut. 2005;54 (1): 54-9. doi:10.1136/gut.2003.032094 - Free text at pubmed - Pubmed citation
- 7. Kiesewetter B, Raderer M. Antibiotic therapy in nongastrointestinal MALT lymphoma: a review of the literature. Blood. 2013;122 (8): 1350-7. doi:10.1182/blood-2013-02-486522 - Pubmed citation
- overview of lymphoma
WHO classification of tumours of haematopoietic and lymphoid tissues
- Hodgkin lymphoma
- mature B-cell lymphoma
- mature T-cell and NK-cell lymphoma
- post-transplant lymphoproliferative/lymphoproliferation disorders
- location-specific lymphomas
- central nervous system
- head and neck lymphoma
- thoracic lymphoma
- gastrointestinal lymphoma
- hepatobiliary lymphoma
- genitourinary lymphoma
- musculoskeletal lymphoma
- cutaneous lymphoma
- lymphoma staging