LEF-1 is a nuclear transcription factor of the Wnt pathway that regulates multipotent skin stem cell differentiation. β-Catenin is considered a transcriptional coactivator that interacts with LEF-1.This study evaluates LEF-1 in a variety of odontogenic and salivary tumors and determines the prevalence of β-catenin coexpression. Ninety-eight salivary gland tumors and 51 odontogenic tumors were evaluated for LEF-1 and β-catenin immunohistochemical staining. Positivity was defined as at least 2+ intensity in more than 50% of tumor cells, which required a composite score of 6 or more. LEF-1 was positive in 64% (7/11) of calcifying cystic odontogenic tumors (CCOT). Nuclear β-catenin was present in 82% (9/11) of CCOT. Coexpression of LEF-1 and nuclear β-catenin was noted in all LEF-1-positive CCOT. Strong and diffuse LEF-1 expression was seen in 69% (11/16) of basal cell adenocarcinomas (BCAC) and 63% (5/8) of basal cell adenomas (BA). Nuclear β-catenin was present in 50% (4/8) of BA and 43% (6/14) of BCAC. For BA, 4 of 5 LEF-1-positive tumors showed coexpression of β-catenin, and for BCAC, 5 of 9 LEF-1-positive tumors showed coexpression. In conclusion, this study documents for the first time the presence of LEF-1 expression and nuclear β-catenin coexpression in select basaloid salivary gland tumors and various odontogenic tumors. We demonstrate LEF-1 expression in both BA and BCAC preferentially over other salivary gland tumors suggesting some utility as a diagnostic marker.
Keywords: Basal cell adenocarcinoma; Immunohistochemistry; LEF-1; Lymphoid enhancer binding factor-1; Odontogenic tumors; Salivary gland tumors; β-Catenin.
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