Mucosa-associated lymphoid tissue (MALT) lymphoma (also known as extranodal marginal zone lymphoma of MALT) accounts for approximately 5% to 8% of all non-Hodgkin's lymphoma.[9]Cohen SM, Petryk M, Varma M, et al. Non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue. Oncologist. 2006;11:1100-17.
http://www.ncbi.nlm.nih.gov/pubmed/17110630?tool=bestpractice.com
[10]The Non-Hodgkin's Lymphoma Classification Project. A clinical evaluation of the International Lymphoma Study Group classification of non-Hodgkin's lymphoma. Blood. 1997;89:3909-3918.
http://bloodjournal.hematologylibrary.org/cgi/content/full/89/11/3909
http://www.ncbi.nlm.nih.gov/pubmed/9166827?tool=bestpractice.com
[11]Zucca E, Bertoni F. The spectrum of MALT lymphoma at different sites: biological and therapeutic relevance. Blood. 2016 Apr 28;127(17):2082-92.
https://www.sciencedirect.com/science/article/pii/S0006497120302172?via%3Dihub
http://www.ncbi.nlm.nih.gov/pubmed/26989205?tool=bestpractice.com
It is the most common type of marginal zone lymphoma (MZL), accounting for approximately 60% of all MZLs.[12]Olszewski AJ, Castillo JJ. Survival of patients with marginal zone lymphoma: analysis of the Surveillance, Epidemiology, and End Results database. Cancer. 2013 Feb 1;119(3):629-38.
https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.27773
http://www.ncbi.nlm.nih.gov/pubmed/22893605?tool=bestpractice.com
The stomach is the most commonly affected extranodal site (gastric MALT lymphoma), accounting for approximately 30% to 40% of cases.[6]Kiesewetter B, Lamm W, Dolak W, et al. Transformed mucosa-associated lymphoid tissue lymphomas: a single institution retrospective study including polymerase chain reaction-based clonality analysis. Br J Haematol. 2019 Aug;186(3):448-59.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6771836
http://www.ncbi.nlm.nih.gov/pubmed/31124124?tool=bestpractice.com
[13]Raderer M, Kiesewetter B, Ferreri AJ. Clinicopathologic characteristics and treatment of marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). CA Cancer J Clin. 2016 Mar-Apr;66(2):153-71.
https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/caac.21330
http://www.ncbi.nlm.nih.gov/pubmed/26773441?tool=bestpractice.com
Other commonly affected sites include the ocular adnexa (24%), lung (12%), and salivary/parotid glands (10%).[6]Kiesewetter B, Lamm W, Dolak W, et al. Transformed mucosa-associated lymphoid tissue lymphomas: a single institution retrospective study including polymerase chain reaction-based clonality analysis. Br J Haematol. 2019 Aug;186(3):448-59.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6771836
http://www.ncbi.nlm.nih.gov/pubmed/31124124?tool=bestpractice.com
The skin, intestinal tract, thyroid, breasts, dura, and genitourinary tract are less commonly affected.[7]Kuo SH, Yeh KH, Lin CW, et al. Current status of the spectrum and therapeutics of Helicobacter pylori-negative mucosa-associated lymphoid tissue lymphoma. Cancers (Basel). 2022 Feb 16;14(4):1005.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8869919
http://www.ncbi.nlm.nih.gov/pubmed/35205754?tool=bestpractice.com
In the US, median age at diagnosis of MALT lymphoma is approximately 67 years.[12]Olszewski AJ, Castillo JJ. Survival of patients with marginal zone lymphoma: analysis of the Surveillance, Epidemiology, and End Results database. Cancer. 2013 Feb 1;119(3):629-38.
https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.27773
http://www.ncbi.nlm.nih.gov/pubmed/22893605?tool=bestpractice.com