Categorisation of Salivary Lesions According to the Novel Milan’s System of Reporting Salivary Gland Cytopathology: A Retro-prospective Study

Introduction: Fine Needle Aspiration Cytology (FNAC) is an important diagnostic tool for salivary lesions, which has decreased the number of unnecessary invasive surgeries for benign conditions. But, cytopathology of salivary lesions is complex presenting with similarity in cytological features albeit with histological heterogeneity. The novel Milan’s System for Reporting Salivary Gland Cytopathology (MSRSGC) is a six tiered classification, providing standard reporting terminology for salivary gland lesions in fine needle aspirates. Aim: To categorise the salivary lesions cytologically based on MSRSGC and to assess its utility in simplification of routine diagnosis of salivary gland lesions. Materials and Methods: A retroprospective study was conducted in a tertiary care centre over a period of five years from 2017 to 2021. All patients suspected to have salivary gland lesions were subjected to FNAC in the Department of Cytology. The cases were reported according to the MSRSGC criteria and assigned one of the categories. The statistical analysis was performed using Microsoft excel software, for calculation of descriptive statistical parameters such as measures of central tendency viz., mean, median, mode, percentage, range and ratio. Results: A sample size of 82 patients with salivary gland lesions was studied. Parotid gland was most commonly involved, among others. Most of the lesions were classified as category 4a (Neoplasm benign) (39%) and category 2 (Non neoplastic) (36.6%). Non Diagnostic (ND) constituted only 2.43% while malignancies constituted 4.9%. Ambiguous categories like Salivary gland neoplasm of Uncertain Malignant Potential (SUMP) and suspicious of malignancy constituted 13.4% and 3.6%, respectively. Conclusion: The introduction of MSRSGC has to a large extent standardised the reporting patterns, thereby assisting the clinicians to render improved patient care. The present study in comparison with other studies conducted worldwide, recommends the usage of MSRSGC for routine reporting.