LMO2 (SP51)

LMO2 is expressed in normal germinal center B-cells and in a subset of lymphomas derived from those cells in addition to bone marrow hematopoietic precursors and endothelial cells. LMO2 protein expression has also been shown to play an important role in the diagnosis of diffuse large B-cell lymphomas, regardless of rituximab treatment. It also plays a role in angiogenesis and hematopoiesis. It is weakly expressed in mantle zone B-cells but not in mantle cell or marginal zone lymphomas. SF Younes et al. Have demonstrated LMO2 expression in 70% of follicular lymphomas. These data suggest that anti-LMO2 is a useful adjunct in the diagnosis of follicular lymphoma (FL). As LMO2 appears not to be down regulated in higher grade FL or the interfollicular and diffuse components of FL, its utility in variant immunoarchitectural patterns of FL and in cases that lack CD10 and bcl2, is similar to that of HGAL. One advantage of LMO2 is its crisp nuclear localization that allows for easier interpretation than diffuse cytoplasmic staining pattern.1