Oncocytic Lesions of Salivary Glands with Morphological and Immunohistochemical Finding

Oncocytic Lesions of Salivary Glands with Morphological and Immunohistochemical FindingsS alivary gland tumors (SGTs) make up less than 5% of all head and neck tumors.[1] 4. According to the 4. Edition of the World Health Organization (WHO) Classification of Head and Neck Tumors, 31 different types of salivary gland epithelial neoplasms have been identified.[2] They may exhibit benign, low-, or high-grade malignant behavior.There may be evident morphological similarities between tumor types and remarkable morphological diversities within a single tumor.Hybrid lesions, dedifferentiation and malig-nant transformation bring on difficulties in the morphological evaluation.Although hematoxylin eosin sections are the basis for diagnosis in most lesions, immunohistochemical markers are important in defining cellular differentiation.Parotid, submandibular and sublingual glands are major salivary glands located in the upper respiratory system.They consist of serous, mucous and mixed acinies, and intercalar, striped and excretory ducts.Epithelial cells are surrounded by myoepithelial cells in acinies and inter-Objectives: Salivary gland neoplasms are less than 5% of all head and neck neoplasms (1).Although there are morphological similarities between different neoplasms, there may be catchy morphological differences in a single tumour.According to the World Health Organization (WHO), 4 th Head and Neck Tumours Classification oncocytic salivary gland lesions are classified as nodular oncocytic hyperplasia, oncocytoma and oncocytic carcinoma.Oncocytic cells may be a component of other salivary gland neoplasms and metastatic malignities.Methods: In this study, salivary gland oncocytic lesions diagnosed in 2016-2017 were evaluated with Haematoxylin and Eosin (H&E) sections and PAS, diastase resistance PAS, p63, DOG1, cytokeratin7 (CK7), androgen receptor (AR) and PAX8 stains.Results: Nineteen cases were benign, two cases were malignant.Eighteen of the benign lesions were Warthin tumour (WT), one case was oncocytoma with nodular oncocytic hyperplasia.Acinic cell carcinoma (AciCCA) with oncocytic cells predominant was one of the malignant cases.The other case was high-grade salivary duct carcinoma (SDCA).Conclusion: The rarity and heterogeneity of this group of lesions may cause difficulties in diagnosis.We present histochemical and immunohistochemical findings of these lesions in light of the literature.