Análise imuno-histoquímica da SCD1 em adenomas pleomórficos, carcinomas mucoepidermoides, carcinomas adenoides císticos e adenocarcinomas polimorfos de glândulas salivares

Abstract

Introduction: Salivary gland neoplasms exhibit a large morphological spectrum, complex cell composition and varied biological behavior. Tumor microenvironment of these lesions can be influenced by several reprogrammed metabolic pathways of neoplastic cells, including the pathways of lipid metabolism. Neoplastic cells use fatty acids (AGs), especially the balance between saturated and monounsaturated AGs (MUFAs), to maintain essential processes in cells such as plasma membrane construction, energy production and energy reservarótio. Stearoyl CoA desaturase-1 (SCD1) is a key enzyme in lipid metabolism, responsible for the regulation between saturated AGs and MUFAs. Role of SCD1 in salivary gland neoplasms is not still elucidated in the literature. Objectives: The present study evaluated the immunoexpression of SCD1 in pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), cystic adenoid carcinoma (CAC) and polymorphic adenocarcinoma (PAC) relating it to clinical and morphological parameters. Methodology: Sample consisted of 20 cases of PA, 20 cases of MEC, 13 cases of CAC and 20 cases of PCA of salivary glands. Clinical parameters evaluated were sex, age and location of lesions, which were collected from medical records. As for the morphological parameters, the PA were classified as poor in cells and rich in cells, the MEC low, intermediate and high degree of malignancy and the CAC in cribriform, tubular and solid growth pattern. For the immunohistochemical study, the primary anti-SCD1 antibody was used and the cytoplasmic positivity index was established in the 8 fields with higher immunoreactivity. Data obtained were statistically analyzed by means of the Kruskal-Wallis tests, post test of Dwass-Steel-Critchlow-Fligner and Mann-Whitney (P< 0.05). Results: A higher frequency of female patients was observed, with an average age between the fourth and sixth decades of life. In relation to the anatomical location of the PA, MEC and PAC minor salivary glands were the most affected, the cases of CAC were more frequent in the major salivary glands. In the evaluation of morphological findings, it was found a higher frequency of PA rich in cells (n = 13; 65%) and CAC of the subtype cribriform (n = 6; 46.1%). In relation to the histopathological degree of malignancy of MEC, there was a predominance of cases with grade I (n=11; 55%). Cytoplasmic expression of SCD1 was higher in the CAC with statistically significant difference when compared to AP (P=0.001), MEC (P<0.001) and PAC (P<0.001). When compared the cytoplasmic immunoexpression of SCD1 with the histological subtype of PA and CAC and the histopathological degree of malignancy of MEC, no statistically significant difference was observed (P>0.050). Conclusion: The results of this study suggest a potential involvement of SCD1 in the pathogenesis of PA, MEC, PAC and CAC of salivary glands. In addition, it can be inferred that there is a positive regulation of SCD1 associated with a less aggressive biological behavior in malignant neoplasms of salivary glands.