Primary Malignant Neoplasms of Parotid Gland in Iranian Population

Background: Salivary gland carcinomas are uncommon tumors and the parotid gland is the most frequent site for them. The incidence of salivary gland cancers vary from different geographic areas and ethnic groups. In this report, we evaluated the pattern of parotid cancer in the Iranian population. Methods: In this multicenter retrospective cross sectional study, the documents of parotid malignant tumors in Shahid Beheshti University of Medical Sciences cancer research center were extracted. The patient records and their microscopic reports were retrieved from the archives and age, gender, and microscopic type were evaluated. Results: Parotid cancers accounted for 0.97% of head and neck malignancies during a 6-year period. The male to female ratio was 1.28 and the majority of the patients were in the 6th decade of their life. Epithelial tumors were the most prevalent malignancies (83.41%), of which mucoepidermoid carcinoma made up 35.57% of all lesions, followed by acinic cell carcinoma (13.94%), and carcinoma ex pleomorphic adenoma (12.5%). In non-epithelial groups, lymphomas accounted for 13.7% of the total lesions and sarcomas constituted 2.88% of the lesions. Of cases, 5.52% were detected within age ranges below 20. Conclusions: In Iranian population, mucoepidermoid carcinoma is the most prevalent malignancy of parotid gland in adults and children. Lymphoma was the most prevalent non-epithelial malignancies in this location. These epidemiologic finding about parotid cancers may improve the knowledge about rare malignancies in adult and younger age range group.