Application and Utility of the Milan System for Reporting Salivary Gland Cytopathology in our institution

Abstract

Objective : We adopted The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) and performed an analysis for evaluation of the risk of malignancy (ROM) with a cyto-histological correlation.

Study Design : Fine needle aspiration (FNA) cytology samples received between 2017 and 2019 from the salivary glands and the neck masses were assigned a diagnostic category from the MSRSGC as follows : Non-diagnostic, Non-neoplastic, Atypia of undetermined significance (AUS), Neoplasm-benign, Neoplasm of uncertain malignant potential (SUMP), Suspicious for malignancy, or Malignant. A correlation with the follow-up histopathology was performed, and the ROM was calculated for all diagnostic categories.

Results : A total of 106 aspirates were collected and classified under the MSRSGC. Follow up histopathology was available for 70 cases and the ROMs for the different categories were as follows : 0% Non-diagnostic ; 33% Non-neoplastic ; 56% AUS ; 0% Neoplasm-benign ; 63% SUMP ; 100% Suspicious for malignancy ; and 100% Malignant. The ROMs in AUS and SUMP were higher than the proposal by the MSRSGC due to low grade malignant lymphoma and low grade carcinoma cases corresponded with this group.

Conclusion : MSRGC is a beneficial diagnostic form to categorize FNA cytological samples and will contribute to patient clinical management. To reduce the ROMs on AUS and SUMP, however, an appropriate ancillary study and a clinicopathologic correlation are required.