Expression of β-catenin in Minor Salivary Glands Adjacent to Oral Squamous Cell Carcinoma

Objective: This study aims to evaluate the expression pattern, localization, and stain intensity of β-catenin in minor salivary glands adjacent to surgically excised oral squamous cell carcinoma (OSCC). Methods: A retrospective study was held with 16 samples of formalin-fixed paraffin-embedded blocks with minor salivary glands adjacent to OSCC. Sections were stained and evaluated immunohistochemically with β-catenin. The staining expression was assessed according to cellular localization, stain intensity, and, lastly, the pattern of stain distribution throughout acini. Statistical analysis was performed using SPSS version 24.0 software for Windows, and data analyzed by Fisher's exact test. P-value <0.05 was considered as statistically significant. Results: All minor salivary glands in the studied sample showed β-catenin staining with different expression in their functional units, as all had ductal and myoepithelial cells staining with a predominant cytoplasmic localization. While the mucous acini showed β- catenin expression in 10 cases (62.5%), this marker was significantly less frequently detected in serous acini of two cases of poorly differentiated OSCC (p= .008). A highly significant relation was found between the β-catenin cellular localization and stain distribution pattern in mucous and serous acini. Conclusions: β-catenin had altered cytoplasmic expression in all of the minor salivary glands adjacent to OSCC. Furthermore, the diffuse pattern of distribution throughout the acini could identify the multi-patches pathological alteration of this area. The current study clarifies that the adjacent clinically normal-appearing salivary glands could harbor genetic aberrations of their subsequent malignant transformation.