Reporting of fine needle aspiration (FNA) specimens of salivary gland lesions: A comprehensive review

Currently, there is no uniform classification scheme available for reporting of salivary gland fine-needle aspiration (FNA) specimens. Recently, an International group of pathologists has recommended a tiered classification scheme for reporting of salivary gland FNA results known as the "Milan System for Reporting Salivary Gland Cytopathology (MSRSGC)." We performed a comprehensive review of the published literature on FNA of salivary gland lesions by employing the diagnostic categories of the MSRSGC to evaluate their reliability in the management of salivary gland lesions. A comprehensive review of the literature was carried out through PubMed from 1987 to 2015 to identify studies which categorized the cytologic diagnoses and included surgical follow-up. Only cases with histopathologic follow-up were included in the analysis. Twenty-nine studies comprising 4514 cases of salivary gland FNAs with surgical follow-up were included in this study. The cytologic diagnoses were categorized into the following categories proposed by MSRSGC. The number of cases in each diagnostic category and the risk of malignancy (ROM) were as follows: Non-Diagnostic-100 cases (ROM- 25.0% ± 16.7%), Non-Neoplastic-587 cases (ROM: 10.2% ± 5.5%), Benign Neoplasm -2673 cases (ROM: 3.4% ± 1.3%), Salivary Gland Neoplasm of Undetermined Malignant Potential (SUMP)-64 cases(ROM: 37.5% ± 24.7%), Suspicious for Malignant neoplasm-70 cases(ROM: 58.6% ± 19.5%), and Malignant-1012 cases(ROM: 91.9% ± 3.5%). A tiered classification scheme as proposed by MSRSGC may prove helpful in effectively guiding clinical management of patients with salivary gland lesions.