Image Description
Parotid MALT Lymphoma - Immunophenotype: Like MALT lymphomas at other locations, these tumors are CD20+, CD79a+, CD5- (occasional cases may be CD5+), CD10- (rare cases are CD10+ but BCL6-), CD23-, and CD11c+/- (weak).
Aberrant expression of CD43 in CD20+ B-cells indicative of neoplastic phenotype is seen in 50% of cases (see next image). There are expanded follicular dendritic cell meshworks that can be visualized with CD21, CD23, and CD35 immunostains. The tumor cells show immunoglobulin light chain restriction.
In this image, note the presence of CD20+ cells within the distorted, CD20-negative ductal epithelial structures (lymphoepithelial lesions).
Aberrant expression of CD43 in CD20+ B-cells indicative of neoplastic phenotype is seen in 50% of cases (see next image). There are expanded follicular dendritic cell meshworks that can be visualized with CD21, CD23, and CD35 immunostains. The tumor cells show immunoglobulin light chain restriction.
In this image, note the presence of CD20+ cells within the distorted, CD20-negative ductal epithelial structures (lymphoepithelial lesions).