Application and Reliability of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC): An Institutional Study

Introduction: Milan System for Reporting Salivary Gland Cytopathology (MSRGC) was introduced in the year 2015 to facilitate a standardised reporting format and to improve the overall effectiveness of fine-needle aspiration cytology (FNAC) in the preoperative evaluation of salivary gland lesions. Risk of malignancy (ROM) provided in each category guides the physician for appropriate clinical management. This study was performed prospectively for one year to evaluate the diagnostic utility and validate MSRSGC. Materials and Methods: The study included lesions in the salivary gland area, including intraparotid lymph node. Cytology material from both direct FNAC, which had rapid onsite evaluation (ROSE) for adequacy and ultrasonography-guided procedures, was included for analysis. Relevant clinical information and imaging findings were obtained. Slides were reviewed, and one of the six categories was applied using the Milan system. ROM and risk of neoplasm (RON) were calculated for each category. Results: The study included 62 cases of salivary gland FNAC of which 35.5% of the cases had surgical resection specimens. Category IVA formed the major group, and only 1.6% was given category III. The ROM and RON were calculated for each category and were statistically significant and compared with other studies. Conclusion: MSRSGC is the recent classification system, and it suggests less than 10% of cases under category III to avoid it’s over utilisation. MSRSGC is a reliable classification in our population, and it was best with category IVA lesions in our study.