Immunoarchitectural patterns of germinal center antigens including LMO2 assist in the differential diagnosis of marginal zone lymphoma vs follicular lymphoma

Abstract

Objectives: To examine the immunoarchitectural patterns of the germinal center (GC)-associated markers CD10, BCL6, and LMO2 and their utility in the differential diagnosis of marginal zone lymphoma (MZL) vs follicular lymphoma (FL). Methods: Forty-two cases of MZL involving lymph nodes and 88 cases of FL were examined. Results: Interfollicular staining for GC markers was uncommon in MZL but common in FL, including BCL2- positive and BCL2-negative cases. Two atypical patterns of intrafollicular GC staining were identified that were more common in MZL than in FL. Conclusions: Staining for LMO2 in addition to CD10 and BCL6 facilitates the detection of a GC phenotype in FL. Lymph nodes involved by MZL frequently show characteristic alterations of GC immunoarchitecture. Recognizing these altered patterns assists in the distinction between MZL and FL. © American Society for Clinical Pathology.