Genotypic characterization of a primary mucoepidermoid carcinoma of the parotid gland by cytogenetic, fluorescence in situ hybridization, and DNA ploidy analysis

We present a case of mucoepidermoid carcinoma with t(3;12)(q24;p13) and polysomy X by cytogenetic and fluorescence in situ hybridization (FISH) techniques. Flow cytometric DNA analysis of the primary tumor showed DNA aneuploidy and analysis of cultured tumor cells showed DNA diploidy indicating restricted growth of the diploid tumor cells in short-term tissue culture. Interphase cytogenetic analysis of chromosomes 1, 3, 6–12, 16–18, and X in the primary tumor showed polysomy 1, 9, 18, and X, monosomy 8 and 17, and disomy 3, 6, 7, 10–12, and 16. Except for chromosome X, other numerical chromosomal abnormalities were not detected by conventional cytogenetic analysis. Our combined approach allowed for better characterization of the genotypic features of this neoplasm.