APPLICATION OF THE MILAN SYSTEM IN CYTOLOGICAL DIAGNOSIS AND MALIGNANCY PREDICTION OF PAROTID GLAND TUMORS

Objectives: In Vietnam, the Milan system for Reporting Salivary Gland Cytopathology has been widely adopted in the cytological diagnosis of parotid gland tumors, contributing to the risk assessment of malignancy and neoplasia in these tumors. This study was conducted to evaluate the utility of the Milan system in fine-needle aspiration cytology (FNAC) by comparing cytological results with histopathological findings of parotid gland tumor cases. Methods: A cross-sectional descriptive study was performed on patients diagnosed with parotid gland tumors at the Department of Otorhinolaryngology, University Medical Center Ho Chi Minh City. Results: From January 2021 to May 2024, 157 patients with parotid gland tumors were included in the study. Among them, 151 patients had unilateral parotid gland tumors, while 6 patients had bilateral parotid gland tumors. Regarding the diagnostic value for malignancy risk, the Milan system demonstrated high sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy. Specifically, the specificity, negative predictive value, and accuracy were above 90%. For neoplastic risk assessment, the Milan system showed high sensitivity, specificity, positive predictive value, and accuracy (over 90%); however, the negative predictive value was relatively low at 55.56%. Conclusion: The Milan system proved highly valuable in distinguishing between benign and malignant lesions and identifying cases requiring classification into uncertain diagnostic categories.