OBJECTIVE: Salivary gland neoplasms pathogenesis has not been well established. 
DNA methylation occurs when methyl groups are added to cytosine nucleotides in 
specific areas of the gene by the enzyme DNA methyltransferase (DNMT). This 
chemical modification can alter gene expression without altering DNA sequence. 
While DNMT3a is mostly involved in de novo methylation, DNMT1 acts as a 
maintenance methyltransferase. We aimed to investigate the immunoexpression of 
DNMT3a and DNMT1 in minor salivary gland neoplasms, comparing it with normal 
tissue.
MATERIAL: Forty-four formalin-fixed and paraffin-embedded samples of pleomorphic 
adenoma, adenoid cystic carcinoma, mucoepidermoid carcinoma and polymorphous 
low-grade adenocarcinoma were included in the study. The DNMT1 and DNMT3a 
proteins were identified by using a highly sensitive polymer-based system.
RESULTS: Positive nuclear and cytoplasmic labeling for DNMT1 was observed in all 
samples, including the controls. Positive nuclear labeling for DNMT3a was found 
only in few neoplasms: 1 pleomorphic adenoma (9.0%), 2 adenoid cystic carcinoma 
(16.6%) and 1 mucoepidermoid (9.0%) cases.
CONCLUSION: Our results were not able to demonstrate a clear correlation between 
DNMT1 and DNMT3a immunoexpression and salivary gland neoplasms development.