Diagnostic Accuracy and Risk Stratification of Salivary Gland Lesions Using the Milan System: A Retrospective Study from Western India

Background: Salivary gland lesions form a small but significant proportion of head and neck pathologies. Fine needle aspiration cytology (FNAC) is a crucial diagnostic tool due to its minimally invasive nature and high diagnostic yield. However, due to the heterogeneity of salivary gland lesions, diagnostic challenges remain. To streamline reporting and enhance diagnostic accuracy, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was introduced. This study aims to analyze the applicability and accuracy of MSRSGC in a tertiary care hospital setting in Western India. Materials and Methods: This is a retrospective study conducted from January 2017 to December 2022 in the Department of Pathology, SBKS MI & RC, Vadodara, Gujarat. A total of 120 FNACs of salivary gland lesions were included. Cytological smears were stained using Hematoxylin and Eosin (H&E), Papanicolaou, and May-Grunwald Giemsa (MGG) stains. Histopathological correlation was available in 50 cases. Risk of malignancy (ROM) was calculated for each MSRSGC category. Results: Most lesions were classified under Category IVa (Benign neoplasms), with pleomorphic adenoma being the most common diagnosis. The sensitivity, specificity, PPV (Positive predictive Value), NPV (Negative predictive Value), and diagnostic accuracy for malignant lesions were calculated. The ROM for each MSRSGC category was compared with existing literature. Conclusion: MSRSGC is an effective classification system that provides consistency and clarity in reporting salivary gland cytopathology. It enables better clinical correlation and management of patients.