title: The Stem Cell Marker Bmi-1 Is Sensitive in Identifying Early Lesions of Carcinoma ex Pleomorphic Adenoma.
abstract: In the present study, we evaluated and described the sensitivity of the stem cell marker B cell-specific moloney murine leukemia virus integration site 1 (Bmi-1) in identifying early lesions of carcinoma ex pleomorphic adenoma (CXPA). While invasive CXPAs are tumors with a prominent and easily recognizable malignant component, the identification of early carcinomatous changes in PA remains a diagnostic challenge due to the lack of objective morphological criteria. The immunohistochemical expression of Bmi-1 was assessed in both adenomatous and carcinomatous components of 9 CXPA cases at an early phase of histological progression (6 intracapsular and 3 minimally invasive) grouped according to the cellular differentiation as luminal (7 cases) or myoepithelial (2 cases). A selective nuclear expression of Bmi-1 was found exclusively in the malignant component of 8 cases (6 luminal type and 2 myoepithelial type), including intraductal carcinoma areas, except for 1 case in which scarce cells of the remnant PA were positive. Thus, Bmi-1 is expressed from the earliest morphologically detectable stages of PA malignant transformation. When faced with atypical features in PA, evaluation of Bmi-1 expression can provide more objective criteria for identification and diagnosis of early lesions of CXPA. This is applied to carcinomas with luminal or myoepithelial differentiation.
authors.affiliation: From the Department of Oral and Maxillofacial Pathology, School of Dentistry, University of São Paulo, São Paulo, Brazil (BTS, MFSDR, FDN, SS); and Department of Anatomic Pathology, School of Medicine, State University of Campinas, São Paulo, Brazil (FVM, AA).
authors.forename: Bruno Tavares
authors.initials: BT
authors.lastname: Sedassari
authors.forename: Maria Fernanda Setúbal Destro
authors.initials: MFSD
authors.lastname: Rodrigues
authors.forename: Fernanda Viviane
authors.initials: FV
authors.lastname: Mariano
authors.forename: Albina
authors.initials: A
authors.lastname: Altemani
authors.forename: Fábio Daumas
authors.initials: FD
authors.lastname: Nunes
authors.forename: Suzana
authors.initials: S
authors.lastname: Sousa
mesh_terms: D008949:Adenoma, Pleomorphic / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D063150:Polycomb Repressive Complex 1 / Q000096:biosynthesis*; D012680:Sensitivity and Specificity
chemical_list: C069077:BMI1 protein, human; D014408:Biomarkers, Tumor; D063150:Polycomb Repressive Complex 1