Study of the Cytomorphology of Salivary Gland Lesions Using the Milan System of Reporting in a Tertiary Care Hospital

Abstract

BACKGROUND Salivary gland neoplasms account for 2-6.5% of all the neoplasms of the head and neck. Any unexplained salivary gland mass is an indication for Fine Needle Aspiration (FNA). Owing to the wide diversity of tumors arising in the salivary glands, diagnostic challenges occur and there is a lack of a uniform reporting system. The MILAN System for reporting salivary gland cytopathology provides a stage for a standardized international reporting system. This paper aims to study the various cytomorphological lesions of salivary gland and their cytological categorisation based on the MILAN system of reporting. METHODS A 4-year cross-sectional study (January 2015 to December 2018) on FNAC of salivary gland lesions was conducted in the Department of Pathology, RIMS, Imphal. All smears were studied based on the classical system and recategorized according to the MILAN Classification into six categories. Histological correlation was carried out for 47 cases and descriptive statistical analysis was done subsequently. RESULTS A total of 291 FNA cases were studied and the original diagnoses included 20 different categories. On categorization of the cases based on the MILAN system, maximum cases were non-neoplastic (52.7%) followed by benign neoplasms (28.8%), atypia of undetermined significance (8.6%), malignant (7.5%), nondiagnostic (1.4%), neoplasms of uncertain malignant potential and suspicious for malignancy (0.3% each). Out of 47 histopathology correlated cases, 39 cases (82.97%) were found to be concordant. CONCLUSIONS Categorization of the FNA findings according to the MILAN System provided a uniform, tiered system for reporting of salivary gland cytomorphology and a platform for a unified staging and risk stratification resulting in better and effective communication between the cytologist and the physician for appropriate management and overall improved patient care.