Chromosomal imbalances, 11q21 rearrangement and MECT1-MAML2 fusion transcript in mucoepidermoid carcinomas of the salivary gland.

The aim of this study was to determine genetic alterations in mucoepidermoid carcinomas of the salivary gland in association with clinical and histopathological parameters. Nineteen formalin-fixed, paraffin-embedded tumors were analysed by using comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH) on interphase nuclei and reverse transcriptase-polymerase chain reaction (RT-PCR) for detection of MECT1-MAML2 fusion transcript. The CGH analysis showed an overrepresentation of chromosome X and losses of entire chromosomes or regions on chromosome 1, 2, and 15 as the most frequent copy number changes. In 37% of the analysed tumors a MAML2-rearrangement by interphase FISH was detected, whereas 58% of the samples showed expression of MECT1-MAML2 fusion transcript. We conclude that the presence of MAML2-rearrangement as well as of MECT1-MAML2 fusion transcript may reflect a more favourable prognosis and may be a useful marker for clinical prediction of the biological behavior of these tumors as previously reported.