The Milan system for reporting salivary gland cytopathology—A single‐center study of 2156 cases

Abstract

Background: Fine-needle aspiration cytology (FNAC) represents an important diagnostic tool for the workup of salivary gland (SG) lesions. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is a six-tiered system for standardizing diagnoses and improvement of communication between pathologists and clinicians, providing risk of malignancy (ROM) rates for every category.The aims of the present study were (i) to validate the use of MSRSGC in a large series of SG FNAC in a tertiary center in Switzerland, (ii) to determine ROM for each category and compare them with data from MSRSGC and similar studies, and (iii) to investigate whether there were relevant differences of non-diagnostic results between fine-needle aspirations (FNA) performed by cytopathologists compared to non-cytopathologists. Methods:The files of the department of Pathology in the University Hospital Zurich (UHZ) were searched for SG FNAC between 2010 and 2019. The MSRSGC guidelines were applied retrospectively. Furthermore, ROM, risk of neoplasia (RON), sensitivity, and specificity were calculated based on the cases with histopathological follow-up. Results: A total of 2156 SG FNAC including 753 cases with histopathological follow-up were evaluated. Generally, ROM was within the range of values provided by MSRSGC, with some minor deviations. Sensitivity was 94.6%, and specificity was 99.3%. Conclusions:Our study confirms the usefulness of MSRSGC. In addition, it provides a detailed insight into the wide spectrum of SG FNAC. Finally, we showed that the rate of non-diagnostic FNA was significantly lower in FNAs performed by cytopathologists compared to non-cytopathologists. K E Y W O R D Scytology, fine-needle aspiration (FNA), Milan system for reporting salivary gland cytopathology (MSRSGC), risk of malignancy (ROM), salivary gland tumors

Cytological features of a lymphoepithelial cyst of the salivary gland with application of the second edition of Milan System for Reporting Salivary Gland Cytopathology

“…Several studies have addressed the usefulness of the first edition of MSRSGC in cytodiagnosis of salivary gland lesions ( 6-12 ). Although it is well recognised that cytodiagnosis of cystic salivary gland lesions is challenging because of the absence or small number of epithelial cells, the utility of MSRSGC in cystic salivary gland lesions has also been reported ( 14 ).…”

“…The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was created as a standardised and reproducible reporting system for classifying salivary FNA cytology specimens in 2018( 5 ). Since then, several studies have addressed the usefulness of this system ( 6-12 ), and it has been used worldwide in daily diagnostic practice of salivary gland cytological examination. The second edition of MSRSGC was published in 2023( 13 ).…”

Molecular analysis using SalvGlandDx improves risk of malignancy estimation and diagnosis of salivary gland cytopathology: An exploratory multicenter study

“…Moreover, category V indicates suspicious for malignancy with some but not all criteria of a malignant diagnosis being fulfilled (ROM 83%-92%). 2,4,5 Although the MSRSGC enables a reproducible classification, interobserver variability in the indeterminate categories is evident 6 and therefore inherently influences the ROM of a category. This uncertainty is especially relevant in tumors of Milan category IVb (salivary gland neoplasm of uncertain malignant potential [SUMP]), which includes entities that later will prove to be either benign or malignant on resection.…”