Histopathological Spectrum and Reported Carcinogen Exposure Profile of Parotid Tumours in Bali, Indonesia: A Retrospective Cross-Sectional Study

Abstract

Background: Parotid tumours account for most salivary gland neoplasms, yet their histopathological distribution has never been characterised in Bali, and exposures common in Balinese households are undescribed in salivary gland series.

Objective: To characterise the histopathological spectrum of parotid tumours and the reported carcinogen exposure profile at a tertiary referral centre in Bali.

Methods: This retrospective cross-sectional study included all 20 patients with a parotid mass and a reportable histopathological diagnosis from January 2020 to December 2024. Proportions were reported with 95% Wilson score confidence intervals and compared with published reference values using exact binomial tests.

Result: Patients were predominantly male (14/20, 70.0%), and 18/20 (90.0%) were aged 41–70 years. Eighteen patients carried two or more exposure classes. Benign lesions predominated (12/20, 60.0%), with pleomorphic adenoma the commonest diagnosis (10/20, 50.0%). High-grade mucoepidermoid carcinoma comprised 6/7 malignancies (85.7%) against an expected 30% (p=0.004), while no Warthin tumour was identified among 18 neoplasms against an expected 30% (p=0.003). Exhaustive bounds analysis showed that no association between patient characteristics and malignancy was identifiable from the available marginal data.

Conclusion: When malignancy occurred in this series it was almost always high-grade, so diagnostic delay carries greater consequence than the malignancy rate alone suggests.