Genomic changes in salivary gland pleomorphic adenomas detected by comparative genomic hybridization

The aim of this study was to investigate whether so far unknown chromosomal alterations in pleomorphic adenoma (PA) exist. To this end, tissue samples from 18 patients with parotid gland PA were studied by comparative genomic hybridization (CGH) using Phi-29-DNA-polymerase for DNA amplification. The most common aberrations were losses of chromosomal material of 19p (6/18), 9q, 16p, and 19q (in 3 out of 18 patients each). Additional losses were observed on 4p, 5q, and 17q (2 / 18 each). Gains involved chromosomes 2p, 4p, 6p, 17q, and 21q (2 / 18 each). Losses of 19p have been associated with inactivation of tumor-suppressor genes in carcinomas previously. As a result, pleomorphic adenomas show a considerable diversity of chromosomal gains and losses detected by CGH. The 19p arm, and particularly its 19p13 region, need be further studied to elucidate the potential impact of associated lost tumor suppressor genes on PA development.