An Investigation of the Clinico-histopathologic Trend of Salivary Gland Tumors in Amir Alam Hospital During 2010- 2019: A Retrospective Study

Background: The incidence and mortality rates of salivary gland tumors have increased according to previous evidence. No study has so far focused on the trend of clinical and histopathologic patterns of salivary gland tumors in Iran. Therefore, the aim was to investigate the incidence and clinico-histopathologic trend of salivary gland tumors in a retrospective, cross-sectional, institutional study from 2010-2019 in Amir Alam hospital. Methods: The archived medical records were collected from patients with the histopathologic diagnosis of benign and malignant salivary gland tumors from Amir Alam hospital, Tehran during (April-April) 2010- 2019. Demographic data and histopathologic features, including tumor size, lymph node involvement, vascular invasion, perineural involvement, and histopathologic differentiation were retrieved, and the samples were categorized and reviewed based on the new classification of head and neck tumors. Finally, the frequencies of characteristics were determined and expressed as numbers (percentage values). Results: Of 1203 salivary gland tumors, 77.6% and 22.4% were benign and malignant, respectively. The incidence of benign tumors was increased from 37 (22.2%) in 2010 to 178 (364.9%) in 2019. In the collection of the total samples, the incidence of malignant tumors was relatively steady from 23 (13.8%) samples in 2010 to 27 (55.35%) in 2019. However, an increase in the incidence of tumors with low-grade differentiation was found from 12.5% in 2010 to 80% in 2019. Conclusions: The incidence of benign and malignant salivary tumors with a higher degree of malignancy had an increasing trend in Amir Alam hospital during 2010-2019.