Frequency and distribution pattern of minor salivary gland tumors in a northeastern Chinese population: a retrospective study of 485 patients.

PURPOSE: The relative frequency of individual minor salivary gland tumors (MSGTs) is not well documented in the literature. The aim of this study was to determine the range and demographics of all histologically diagnosed MSGTs in a northeastern Chinese population.

MATERIALS AND METHODS: A total of 485 cases of MSGT were retrospectively studied. The files of the Department of Oral and Maxillofacial Pathology, School of Stomatology, China Medical University served as a source of material for this study. All epithelial tumors from minor salivary glands accessioned from August 2004 to April 2014 were analyzed for demographic features, anatomic location of tumors, and pathologic classification. Tumors were classified according to the 2005 World Health Organization classification of salivary gland tumors. Statistical analysis was performed using analysis of variance.

RESULTS: MSGTs were identified in 485 (2.60%) of 18,670 accessed cases. There were 268 (55.26%) benign and 217 (44.74%) malignant tumors. Female outnumbered male patients (male-to-female ratio, 1:1.43). The mean ages of patients with benign and malignant MSGTs were 47.58 and 51.51 years, respectively. Pleomorphic adenoma and adenoid cystic carcinoma were the most frequent types of benign and malignant tumors, respectively. The palate was the most commonly affected site (64.74%), followed by the buccal mucosa (7.63%) and the tongue (5.98%).

CONCLUSIONS: From the results of this study and a review of the literature, it is suggested that MSGTs in the northeastern Chinese population may be characterized by a higher incidence of MSGTs than in the populations of other reviewed regions, a higher incidence of myoepithelioma, a rarer occurrence of polymorphous low-grade adenocarcinoma, and an absence of canalicular adenoma occurrence.