(A232) Parotid Incidentalomas: A Clinicopathologic Review over 5 Decades

Introduction: Parotid incidentalomas are rare but have been shown to represent an increasing percentage of patients with parotid tumors in prior studies. In this study, we aim to explore the incidence, demographics, tumor histology, and tumor characteristics of patients who present with an incidentally noted parotid mass in a single county over five decades.

Methods: This is a retrospective cohort study of all patients with a diagnosis of a parotid mass from January 1, 1976, through December 31, 2022 in a single county identified using a record linkage system. Inclusion criteria included all parotid masses found via incidental imaging. Demographics, tumor size, smoking status, final pathology, and methods of intervention were collected. Incidence was calculated per 100,000 person-years. Trend analysis was performed using linear regression.

Results: 128 patients presented with an incidental imaging finding of a parotid mass from 1/1/1976 to 12/31/2022, with an average annual incidence of 1.79/100,000 person years. There was a significant increase in incidence from 0 in 1976-1979 to a high of 5.3/100,000 person years in 2020-2022 (p=0.02). 20 patients underwent no further diagnostic work up or underwent FNA that was non-diagnostic. 55% of patients underwent definitive surgical management. Out of the patients with pathologic diagnoses, 94% (n=102) were benign pathologies. The most common pathology was pleomorphic adenoma (n=45, 42%), followed by Warthin’s tumor (n=38, 35%). The most common imaging modality for detection was MRI (n=55, 43%), followed by CT (n=46, 36%). The median tumor size found was 1.6 cm, with the majority of tumors located in the superficial lobe (n=80, 68%). The median age at imaging presentation was 64.7 years and the average time from imaging to diagnosis was 166 days.

Conclusions: Most patients who presented with an incidental parotid mass on imaging over the last 5 decades had benign pathology. The most common tumors found were pleomorphic adenoma and Warthin’s tumor. These findings may improve patient counseling in the otolaryngologist’s office for this increasingly common chief complaint.