Expression of CXCR3 in B-cell lymphomas with varying degrees of plasmacytic differentiation.

(A) Low-grade extranodal marginal zone lymphoma (MALT lymphoma) of stomach showing CXCR3 in clusters of plasma cells (white arrows) and not in the majority of infiltrating small lymphocytes. (B) Salivary gland MALT lymphoma with sheets of CXCR3-positive interfollicular “monocytoid” neoplastic B cells. Admixed non-neoplastic follicles and associated mantle zones are negative for CXCR3, as are salivary ducts and glands (black arrows). (C) Diffuse CXCR3 staining in a low-grade MALT lymphoma of the lung with extensive plasmacytic differentiation. Epithelial elements are negative.