Salivary gland neoplasms in oral and maxillofacial regions: a 23-year retrospective study of 6982 cases in an eastern Chinese population☆

There is little information in the English-language literature about the epidemiology of salivary gland neoplasms in the eastern Chinese population. A large retrospective study (6982 primary salivary tumors during 23 years) was carried out to investigate the clinicopathological features (tumor location, patient sex and age) of these tumors in this population. 3593 tumors were in males and 3389 in females. Pleomorphic adenoma (69%) was the most common tumor and 20% were located in minor glands. 92% of Warthin's tumors occurred in males. Malignant tumors were predominantly adenoid cystic carcinoma (30%) and mucoepidermoid carcinoma (30%). Incidences of lymphoepithelial carcinomas (5%) and polymorphous low-grade adenocarcinoma (1%) of malignant tumors were identified. 28% of tumors originated from minor glands. Most findings were similar to those in the literature, with some variations. The salivary tumors slightly predominated in males. Relatively higher incidences of minor gland tumors and specifically of pleomorphic adenoma in minor glands were noted. Adenoid cystic carcinoma and mucoepidermoid carcinoma constituted the most common malignancies. There was a high incidence of lymphoepithelial carcinomas but a low incidence of polymorphous low-grade adenocarcinoma. The historical significant male predominance of Warthin's tumor was confirmed.