Oral and maxillofacial pathologyCarcinoma ex-pleomorphic adenoma of upper lip showing copy number loss of tumor suppressor genes

BackgroundCarcinoma ex-pleomorphic adenoma (CXPA) is a malignant salivary gland tumor that arises rarely in the minor salivary glands. Although the etiology of CXPA remains unclear, the role of some tumor suppressor genes and oncogenes in CXPA is documented; however, other genes still need to be studied.Study design and objectiveAn uncommon case of CXPA involving the upper lip is presented, which was analyzed by a panel of tumor suppressor genes by multiplex ligation-dependent probe amplification.ResultsThe genes investigated in this study, a loss of copy number was detected for CASP8, CD44, CDH1, DAPK1, ESR1, RASSF1, and TP73. Immunohistochemical reactions for the validation of some of these results showed negativity for CD44, RASSF1, and p73.ConclusionA loss of copy number of the genes CD44, RASSF1, and TP73 may contribute to the carcinogenesis of CXPAs.