Are differences in the expression of carbohydrate-binding sites (endogenous lectins) responsible for recurrences of benign tumours of the parotid gland?

The expression of endogenous lectins in pleomorphic adenomas and papillary cystadenoma lymphomatosum (Warthin tumour) as well as in the tissue of the normal parotid gland was investigated with the aim to determine the capacity of the different cells to specifically bind carbohydrate ligand structures. The loss of sugar-binding sites of pleomorphic adenomas - lactose (diazonium derivative; diaz.), beta-N-acetylgalactosamine (diaz.), sialic acid [(2,3-epoxypropane)-4-oxybutyric acid linked; epichl.], heparin, mannose-6-phosphate (diaz.), maltose (diaz.), xylose (diaz.), melibiose (diaz.), N-acetylgalactosamine (epichl.) - was detected in the investigated tumours, leading to the hypothesis that altered carbohydrate-protein interactions have been involved in the adhesion of lost pleomorphic adenoma cells after damaging the tumour capsule. The papillary cystadenoma lymphomatosum in its cytoplasmic areas expressed significantly fewer sugar-binding sites for alpha-N-acetylgalactosamine (diaz.) and melibiose (diaz.).