Exploring salivary gland lesions: Unveiling malignancy risks using the Milan classification

Salivary gland tumours (SGTs) are characterized by exceptional heterogeneity, diversity, and frequent morphological overlap among different entities. Fine needle aspiration cytology (FNAC) plays a pivotal role in evaluating salivary gland lesions (SGLs), facilitating prompt and accurate diagnosis and treatment. The Milan System of Reporting Salivary Gland Cytology (MSRSGC) is a six-tiered reporting system that aims to standardize SG reporting, fostering consistency in clinical management.

To assess the cytomorphological patterns of various SGLs and categorize them according to MSRSGC. To study the frequency of SGLs by demographics, evaluate the efficacy of FNAC, and determine the risk of malignancy (ROM) through cyto-histo correlation.

This descriptive cross-sectional study involved 80 FNAC cases of SGLs sent to the pathology department from January 2018 to September 2022 (five years). Cytological findings were meticulously evaluated, categorized according to the MSRSGC, and correlated with histology wherever available.

Out of a total of 80 cases, 34 were available for histopathological examination. The predominant age group affected was 51-60 years (23.75%) and the male-to-female ratio was 1.9:1. The parotid gland was most commonly involved (69%), followed by the submandibular gland (26%) and the minor salivary gland (5%). The frequency of case distribution according to MSRSGC in Categories I, II, III, IVA, IVB, V, and VI was 8%, 11%, 5%, 53%, 16%, 3%, and 5%, respectively. The ROM reported for each category was 0%, 0%, --, 6.25%, 40%, 100%, and 100%, respectively. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were of 80%, 100%, 100%, 94.44%, and 95.45%, respectively, underscoring its clinical utility. Among the available histological follow-up cases, maximum cases were available in Category IVB (77%), followed by Category VI (75%).

FNAC proves to be a reliable diagnostic tool for SGLs, despite the inherent challenges of heterogeneity. Employing the MSRSGC enhances diagnostic precision, mitigating the risk of false positives and false negatives, thereby improving clinical outcome.