CONTRIBUTION OF QUANTITATIVE LECTIN HISTOCHEMISTRY TO CHARACTERIZING WELL-DIFFERENTIATED, DEDIFFERENTIATED AND POORLY DIFFERENTIATED LIPOSARCOMAS

OBJECTIVE: To find new diagnostic markers in the group of lipomatous t umors. STUDY DESIGN: The histochemical lectin staining pattern was cha racterized in a series of 45 lipomatous lesions, including 10 typical lipomas, 6 atypical lipomas, 8 well-differentiated, 6 myxoid, 5 dediff erentiated and 10 pleomorphic liposarcomas. Three lectins were used - peanut (Arachis hypogaea) agglutinin, which binds to terminal Gal(beta 1,3)GalNAc residues; wheat germ (Triticum vulgare) agglutinin (s-WGA, the succinylated form of WGA), which binds to ((1-4)-D-GlcNAc)n and N eu5NAc residues; and jack bean (Concanavalia ensiformis) agglutinin wh ich binds to alpha-D-Man and alpha-D-Glc residues. Histochemical stain ing was quantitatively measured by means of a cell image processor. RE SULTS: In the case of certain carbohydrate residues, typical lipomas c losely resemble atypical lipomas, which in turn closely resemble well- differentiated liposarcomas; typical lipomas differ significantly from well-differentiated liposarcomas. This indicates that atypical lipoma s, or at least some of them, could represent a biologic link between t ypical lipomas and well differentiated liposarcomas. While well-differ entiated and pleomorphic liposarcomas differed significantly from each other, the poorly differentiated component of dedifferentiated liposa rcomas included histochemical lectin properties, which were common to both well-differentiated and pleomorphic liposarcomas. CONCLUSION: Som e atypical lipomas exhibit glycohistochemical characteristics that are common to those of well-differentiated liposarcoma. The poorly differ entiated component of dedifferentiated liposarcomas remains more diffe rentiated in terms of glycohistochemical markers than do poorly differ entiated pleomorphic liposarcomas.