Abstract
PURPOSE: The t(11;18)(q21;q21) chromosome translocation is frequent in gastric MALT lymphoma, but the t(11;18)(q21;q21) chromosome translocation is very rare in other sites of MALT lymphomas. We investigated the possibility that MALT lymphoma occurred in the right buccal mucosa of a 66-year-old Japanese woman who had the t(11;18)(q21;q21) chromosome translocation. METHODS: Tumor specimens were examined by light microscopy and immunohistochemistry. To investigate where the present case has API-MALT1 fusion, we used the nested PCR and FISH analysis. RESULTS: Some colonized lymphoid follicles with mantle zone were observed on low-power field, and centrocyte-like cells and monocytoid B cells were observed on high-power field. Immunohistochemical staining of the tumor was positive for bcl-2, CD20, CD79a, CD43, Lambda, Kappa and was negative for CD10, IgG, IgG4, IgM, cyclin D1, bcl-6, CK (AE1/3), Helicobacter pylori. Using the nested PCR and FISH analysis, present case had the t(11;18)(q21;q21) chromosome translocation (A1446-M1150). CONCLUSION: We report that MALT lymphoma in buccal mucosa has the t(11;18)(q21;q21) chromosome translocation (A1446-M1150) by using the nested PCR and FISH analysis. This is the first report of the t(11;18)(q21;q21) chromosome translocation (A1446-M1150) of MALT lymphoma in the oral cavity.