Mucosa-associated lymphoid tissue lymphoma: Molecular pathogenesis and clinicopathological significance
Article first published online: 1 JUL 2007
Volume 57, Issue 8, pages 474–484, August 2007
How to Cite
Inagaki, H. (2007), Mucosa-associated lymphoid tissue lymphoma: Molecular pathogenesis and clinicopathological significance. Pathology International, 57: 474–484. doi: 10.1111/j.1440-1827.2007.02128.x
- Issue published online: 1 JUL 2007
- Article first published online: 1 JUL 2007
- Received 31 January 2007. Accepted for publication 10 April 2007.
- API2-MALT1 fusion;
- autoimmune disease;
- chronic inflammation;
- cytogenetic alterations;
- Helicobacter pylori;
- mucosa-associated lymphoid tissue (MALT) lymphoma;
Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade tumor closely associated with chronic inflammation such as that of Helicobacter pylori gastritis, Sjogren's syndrome, and Hashimoto's thyroiditis. Tumor regression by H. pylori eradication alone is well known in gastric MALT lymphoma, but some tumors occur in the absence of pre-existing chronic inflammation. The understanding of MALT lymphoma biology has significantly improved, and recurrent cytogenetic alterations have been detected. These include the trisomies 3 and 18, and the translocations t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). At least some of these alterations result in the constitutive activation of the nuclear factor (NF)-κB pathway, and may exert anti-apoptotic action. Apoptosis inhibitor 2–MALT lymphoma-associated translocation 1 (API12-MALT1) fusion, resulting from t(11;18)(q21;q21), is specific to, and is the most common in, MALT lymphomas, and its clinicopathological significance has been studied extensively. The focus of the present review is on the recent progress made in elucidating MALT lymphomagenesis and its clinicopathological impact, especially in terms of the effect of API2-MALT1 fusion on this unique tumor.