According to pairwise comparisons (Mann-Whitney), a significantly lower expression of syndecan-1 percentage was observed in the stroma of pleomorphic adenoma compared to adenoid cystic carcinoma (p = 0.04) and syndecan-1 intensity+percentage in mucoepidermoid carcinoma (both, p < 0.001). This evidence concerns the gene SDC1 and adenoid cystic carcinoma.