Expression of PLAG1, HMGA1 and HMGA2 in minor salivary glands tumours

Background: Diagnosis of minor salivary gland (MSG) tumours is often difficult, due to the scarce tissue obtained from bioptic excision and complex histopathological differential diagnosis. In our study we performed an immunohistochemical analysis of PLAG1, HMGA1 and HMGA2 on a series of MSG tumours, in order to develop a new helpful diagnostic panel. Methods: A retrospective series of 17 surgical specimens of MSG tumours were analysed for the expression of PLAG1, HMGA1 and HMGA2. Three control cases were enrolled and analysed. An intensity and percentage-based approach was performed, creating a combined score panel. Results: PLAG1 facilitate the diagnosis of benign tumours, discriminating it from malignant histotypes, with a defined cut-off value. Similarly, HMGA1 is significantly higher in benign histotypes than in malignant ones. HMGA2 in our series, did not reveal any association in identifying benign from malignant histotypes. Conclusions: In this study we assessed the diagnostic role of PLAG1, HMGA1 and HMGA2 immunohistochemical analysis. The score panel facilitate histopathological diagnosis of these rare tumours, helping to distinguish benign tumours from malignant ones and ameliorating the differential diagnosis of specific histotypes.