title: Lectin histochemistry of malignant tumors. II. Concanavalin A: a new histochemical marker for macrophage-histiocytes in follicular lymphoma.
abstract: Concanavalin agglutinin (Con A) binding sites were studied in paraffin embedded lymph node specimens of reactive follicular hyperplasia (12 cases) and follicular lymphoma (37) using the avidin-biotin-peroxidase complex method, and the results were compared with those of Peanut agglutinin (PNA) and lysozyme stains. Very similar to the PNA stain, two categories of Con A receptor sites were observed: cytoplasmic and cell surface. In the reactive lymph nodes, the cells showing cytoplasmic receptor sites (CR+ cells) corresponded to macrophage-histiocytes and possibly dendritic reticulum cells in the H & E stained sections, while those showing cell surface receptor sites (SR+) corresponded to lymphoid cells. Unlike the PNA binding, however, the staining reaction of SR+ lymphoid cells was weak, and another staining pattern, a dot-like stain, was observed in some lymphocytes, both SR+ and SR-. In follicular lymphomas, CR+ histiocytes were distinctly displayed within the follicular centers in 25 of 37 cases, including 12 cases in which PNA stains on adjacent or nearby sections were negative for intrafollicular macrophage-histiocytes. Similarly, Con A stains were positive for the intrafollicular CR+ cells in four of the five cases in which lysozyme stains were negative. Many of these intrafollicular CR+ cells contained inclusion-like cytoplasmic globules and/or vacuoles, a hallmark of the large CR+ cells of germinal centers. These observations suggest that macrophage-histiocytes of presumably germinal center origin are retained in neoplastic follicular centers in varying degrees, and Con A might be a useful marker for macrophage-histiocytes in paraffin-embedded routine pathological specimens, in addition to the currently accepted markers, PNA and lysozyme.
mesh_terms: D002462:Cell Membrane / Q000032:analysis; D003208:Concanavalin A / Q000378:metabolism*; D003593:Cytoplasm / Q000032:analysis; D005260:Female; D006644:Histiocytes / Q000378:metabolism*; D006651:Histocytochemistry / Q000379:methods*; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism; D008198:Lymph Nodes / Q000473:pathology; D008223:Lymphoma / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011952:Receptors, Concanavalin A / Q000032:analysis* / Q000378:metabolism; D013194:Staining and Labeling
chemical_list: D011952:Receptors, Concanavalin A; D003208:Concanavalin A