Identification of MNDA as a new marker for nodal marginal zone lymphoma.

Clinical and biological studies on nodal marginal zone lymphoma (NMZL) are hampered by the lack of specific diagnostic markers and the low reproducibility of this diagnosis. A comparative expression-profiling study has shown a set of markers to be differentially expressed in NMZL compared with follicular lymphoma (FL), including myeloid cell nuclear differentiation antigen (MNDA), a nuclear protein expressed by myeloid cells and a subset of B-cells. The aim of this study was to characterize the expression of MNDA in normal and reactive human tissue, and in a large series of non-Hodgkin's B-cell lymphomas, with particular emphasis on NMZL and FL. Our results showed that MNDA is expressed in normal tissue by a subset of the marginal zone B cells. They also showed MNDA expression in subgroups of chronic lymphocytic leukemia, mantle-cell lymphoma, and diffuse large B-cell lymphoma, but MNDA was especially expressed by lymphomas derived from the marginal zone, such as mucosa-associated lymphoid-tissue lymphoma, splenic marginal-zone lymphoma and NMZL. MNDA expression was rarely observed in FL, a characteristic that is of potential value in distinguishing between NMZL and FL. MNDA expression is thus a useful tool for the recognition of NMZL.