Tumours of the salivary glands in northeastern China: a retrospective study of 2508 patients.

Little information has been published in English about the epidemiology of tumours of the salivary glands in northeastern China. From August 2004 to March 2014, 2508 cases of primary epithelial salivary gland tumours were diagnosed in the Department of Oral and Maxillofacial Surgery, the Affiliated Stomatology Hospital of China Medical University. Tumours were analysed according to their histological type and site, and the age and sex of the patients. Ages ranged from 5 to 98 years, with a slight propensity in favour of men. The peak incidence was in the sixth decade for both sexes. The mean (SD) ages were 48 (16) years when the tumour was benign and 51 (15) years when it was malignant. The parotid gland and palate were the sites most commonly affected. There were 1934 (77.1%) benign and 574 (22.9%) malignant tumours, with the most common histological types being pleomorphic adenomas and mucoepidermoid carcinomas. A lesion that arises from the floor of the mouth (92.8%) or the tongue (86.2%) is more likely to be malignant than those from other minor salivary glands.