Triglyceride-Glucose Index in Parotid Gland Tumours: A Novel Biomarker for Differentiating Warthin Tumour and Pleomorphic Adenoma

Pleomorphic adenoma and Warthin tumour are the two most common benign parotid gland tumours with distinct histological and clinical profiles. Recent studies suggest a potential link between metabolic disturbances-particularly insulin resistance-and the development of Warthin tumours. The triglyceride-glucose (TyG) index has emerged as a simple, cost-effective biomarker of insulin resistance. This study aimed to investigate the potential role of the TyG index in differentiating between pleomorphic adenoma and Warthin tumour.

A retrospective cross-sectional study was conducted on patients histopathologically diagnosed with pleomorphic adenoma (n = 31) or Warthin tumour (n = 22), and compared with healthy controls (n = 58). Fasting glucose and triglyceride levels were used to calculate the TyG index. Statistical analyses included t-tests, ANOVA, and Bonferroni-corrected post hoc comparisons, with a significance threshold of p < 0.05.

No significant differences were observed in age, sex, BMI or TyG index between the tumour group and controls. However, the TyG index was significantly higher in the Warthin tumour group (4.91 ± 0.28) compared to the pleomorphic adenoma (4.68 ± 0.31, p = 0.006) and control groups (4.72 ± 0.23, p = 0.033). No difference was found between the pleomorphic adenoma and control groups.

The TyG index is significantly elevated in patients with Warthin tumours, supporting its potential role as a simple, non-invasive biomarker to aid in the differential diagnosis of benign parotid tumours.