Characteristics of Cutaneous Marginal Zone Lymphomas With Marked Plasmacytic Differentiation and a T Cell-Rich Background

Departmentsof Pathology, Massachusetts General Hospital, Boston, MA 02114, USA.
American Journal of Clinical Pathology (Impact Factor: 3.01). 01/2010; 133(1):59-69. DOI: 10.1309/AJCPW64FFBTTPKFN
Source: PubMed

ABSTRACT Primary cutaneous marginal zone lymphoma (MZL) is a common B-cell lymphoma of skin and is characterized by an infiltrate of neoplastic marginal zone B cells typically within the marginal zones of reactive lymphoid follicles and the interfollicular region. However, in our experience, many cases have underemphasized features such as marked plasmacytic differentiation and/or a prominent T-cell component, which may obscure the neoplastic B cells and lead to misdiagnosis. We wanted to draw attention to these features and have studied 15 cases of MZL with marked plasmacytic differentiation, 10 of which had numerous T cells, some with cytologic atypia, and few B cells in the interfollicular region. Plasma cells were monotypic in all cases by in situ hybridization. By polymerase chain reaction, 6 of 8 T cell-rich cases had an IGH gene rearrangement, and none were clonal for T-cell receptor gene. We discuss the terminology, morphologic features, molecular profile, behavior, and differential diagnosis of cutaneous MZL.

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