Primary Epithelial Minor Salivary Gland Tumors in South Africa: A 20-Year Review

Minor salivary gland tumours represent 9-25% of all salivary gland tumours. South African epidemiological reports on minor salivary gland tumours are lacking. This study aims to evaluate the frequency, epidemiology and histology of minor salivary gland tumours in a defined South African population from 1997 to 2016. This cross sectional retrospective review of epithelial minor salivary gland neoplasms recorded patient demographic data: prevalence, age, gender, site, histology. There were 553 benign (57%) and malignant (43%) minor salivary gland tumours, in patients between the ages of 9 and 93 years. There was no significant age (p = 0.64) or gender (p = 0.18) difference between males and females. Common histologic types of salivary gland tumours in the continually evolving spectrum were pleomorphic adenoma (52%), adenoid cystic carcinoma (12%) and mucoepidermoid carcinoma (10%). Common sites were the palate (56%), cheek (11%), lip (9%) and paranasal sinuses (7%). Minor salivary gland tumours represent 2.3% of head and neck pathology. Although this prevalence is higher than reported, there is no overall increase in number diagnosed per year. Minor salivary gland tumours were more prevalent in females. Benign tumours occurred at a younger age than malignant tumours. This study serves as a baseline for future studies, especially in South Africa.