A FLUORESCENCE IN-SITU HYBRIDIZATION (FISH) ANALYSIS WITH CENTROMERE-SPECIFIC DNA PROBES OF CHROMOSOME-3 AND CHROMOSOME-17 IN PLEOMORPHIC ADENOMAS AND ADENOID CYSTIC CARCINOMAS

Aberrations of chromosomes 3 and 17 were studied by FISH using centrom ere-specific DNA probes in 11 salivary adenoid cystic carcinomas (ACC) and 8 salivary pleomorphic adenomas (PA), with 3 lymph nodes as contr ols. Two hybridized signals were detected in 92.8+/-2.7% of controls, 73.2+/-7.0% of PA and 66.8+/-7.9% of ACC cells for chromosome 3, and i n 90.4+/-2.3% of controls, 59.5+/-25.0% of PA and 44.8+/-20.2% of ACC for chromosome 17. More than 3 hybridized signals, which indicate poly somy, were observed in 3.1% of controls, 15.5% of PA and 22.9% of ACC cells for chromosome 3? and in 1.2% of controls, 10.3% of PA and 23.1% of ACC cells for chromosome 17. A single hybridized signal was much m ore frequent for chromosome 17 than for chromosome 3. These findings s uggest that polysomy of both chromosomes occurs during the development of salivary gland tumors, and its frequency is increased in adenoid c ystic carcinoma as compared to pleomorphic adenoma. In addition, monos omy of chromosome 17 could possibly be significant in salivary gland t umors.