Epithelial-myoepithelial carcinoma harboring p53 mutation

A case of epithelial-myoepithelial carcinoma of the parotid gland harboring p53 mutation is reported. The tumor removed from a 67-year-old Japanese female was composed of an organoid biphasic population of cells: inner dark epithelial cells were surrounded by clear myoepithelial cells. The cells were immunopositive for EMA and smooth muscle actin, respectively. Some of the epithelial cells formed solid nests. Immunostaining for proliferating cell nuclear antigen (PCNA) resulted in a higher percentage of labeled cells in the solid epithelial region than in the region with the more general biphasic pattern. Genetic analysis, including polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and nucleotide sequencing, revealed a mutation in codon 207 (aspartic acid to glycine) of the p53 tumor-suppressor gene. To our knowledge, this is the first report of a mutation in the p53 gene in an epithelial-myoepithelial carcinoma of the salivary gland.