MRI features of mucosa-associated lymphoid tissue lymphoma in the breast.

4Department of Pathology, Stanford University, Stanford, CA. xtranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue, or MALT lymphoma, is a non-Hodgkin’s lymphoma associated with chronic inflammation. It typically occurs in the gastric mucosa or the thyroid parenchyma, and is rarely reported in the breast [1]. Histologically, MALT lymphoma is characterized by heterogeneous small B-cells infiltrating the marginal zone of reactive lymphoid follicles and extending into epithelial tissues. Although usually indolent, this tumor can be locally aggressive and is treated with local radiation therapy and/or systemic chemotherapy [2]. Breast lymphomas may present as a palpable breast lump or as an irregular solitary mass discovered during a screening mammogram [3]. A few case reports have described the MRI appearance of primary breast non-Hodgkin’s lymphoma, but none to our knowledge have described MALT lymphoma [4, 5]. In this report, we present the MRI findings of MALT lymphoma arising in the breast.