Introduction of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC)

Abstract

Fine needle aspiration (FNA) has come to be widely accepted as an efficient first-line diagnostic test for salivary gland lesions. However, the inherent complexity of salivary gland FNAC poses unique challenges. Therefore, a new reporting system for salivary gland cytology specimens has been developed as an international standard, and is designated as The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC). The MSRSGC consists of the following six diagnostic categories : “Non-diagnostic”, “Non-neoplastic”, “Atypia of undetermined significance (Aus)”, “Neoplasm”, which is subcategorized into “Benign” and “Salivary gland neoplasm of uncertain malignant potential (SUMP)”, “Suspicious for malignancy,” and a “Malignant”. It is an evidence-based system derived from the literature, and the diagnostic categories have been shown to be correlated with the risk of malignancy (ROM) and to reliably guide clinical management strategies. Neoplastic salivary gland lesions are usually managed surgically. Thus, the MSRSGC differentiates between neoplastic and non-neoplastic salivary gland lesions as separate categories. In addition, ancillary studies and clinical and radiological correlations are also recommended. The MSRSGC is a practical and useful reporting system that meets clinical needs and is expected to become widely accepted in Japan.