Adenoid dysplasia of the oral mucosa.

OBJECTIVE To describe an unusual variant of oral epithelial dysplasia and to provide an appraisal of its immunohistochemical profile. STUDY DESIGN An unusual form of epithelial dysplasia, which we have termed adenoid dysplasia, was evaluated for staining of cytokeratins AE1/AE3, vimentin, E-cadherin, and β-catenin. The immunohistochemical results were compared with those observed in moderate epithelial dysplasia, moderately differentiated squamous cell carcinoma, and acantholytic squamous cell carcinoma. RESULTS The immunoprofile of adenoid dysplasia was similar to that of acantholytic squamous cell carcinoma. Cytokeratin positivity within the acantholytic dysplastic cells confirmed their epithelial nature, and upregulation of vimentin was suggestive of epithelial-mesenchymal transition. The most distinctive finding was a loss of E-cadherin expression within the discohesive cells, accompanied by increased cytosolic expression of β-catenin. CONCLUSIONS This report presents the histomorphologic features of a unique form of oral epithelial dysplasia, termed adenoid dysplasia.