BACKGROUND: Salivary gland neoplasms are heterogeneous, with wide cytomorphological overlap. Neoplasms categorized in the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) as salivary gland neoplasms of uncertain malignant potential (SUMP) reflect this diagnostic challenge. METHODS: All salivary gland fine-needle aspirations (SG-FNA) diagnosed at Fimlab Laboratories over a 5-year period (January 1, 2018-December 31, 2022) that were classified as SUMP were included. Follow-ups were reviewed until May 31, 2024. The SUMP cases were classified into cytomorphological subtypes. The risk of malignancy (ROM), risk of neoplasm, and median timelines of the pathology laboratory workflow and patient management were calculated. In addition, separate analyses of the impact of age and sex were performed. RESULTS: A total of 1157 SG-FNAs were diagnosed over a 5-year period. Of these, 100 SG-FNAs from 52 females and 33 males were classified as SUMP. A total of 69 (69.0%) SUMP cases underwent histological verification. The ROM was 23.2% for all surgical follow-ups, 35.0% for the oncocytic/oncocytoid subtype, and 18.4% for the basaloid subtype. For the male and female groups, the ROMs were 26.9% and 16.2% for all surgical follow-ups, 40.0% and 14.3% for the oncocytic/oncocytoid subtype, and 18.8% and 16.7% for the basaloid subtype, respectively. CONCLUSIONS: The 5-year analysis of SUMP category performance showed a lower ROM in our practice than the MSRSGC reference value. The oncocytic/oncocytoid subtype presented a higher ROM than the basaloid subtype. The ROMs were highest in the male population and in the age group of 30-69 years.

• Klíčová slova
• Milan system for reporting salivary cytopathology, SUMP, fine‐needle aspiration, salivary gland, salivary gland neoplasm of uncertain malignant potential,
• MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• nádory slinných žláz * patologie   diagnóza   klasifikace   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• slinné žlázy patologie   MeSH
• tenkojehlová biopsie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

INTRODUCTION: Warthin's tumour (WT) is the second most common salivary gland neoplasm. With classic cytomorphological features of WT, the diagnostic accuracy is over 95%. WT is usually categorized as benign neoplasm according to the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC). METHODS: Database search at the Department of Pathology, Fimlab Laboratories, Tampere, Finland, revealed 146 WTs during a 10-year period (January 1, 2013-December 31, 2022). Diagnostic accuracy was calculated for the entire study period, and the study period divided in half to pre-MSRSGC years (2013-2017) and MSRSGC years (2018-2022). In addition, a separate cytomorphology analysis of false-negative cases that were classified according to the MSRSGC was performed. RESULTS: Diagnostic accuracy was 96.4%, sensitivity was 68.5%, and specificity was 99.8%. Sensitivities and specificities were almost equal during the pre-MSRSGC years and the MSRSGC years. The number of true-positive cases was 113. Fifty-five cases (52 false-negative and 3 false-positive cases) were not accurately diagnosed. Risk of malignancy and risk of neoplasm were 0.0% and 98.3% of cases that were cytologically diagnosed as WT. Cytomorphological analysis showed that lack of papillae, the presence of small groups, and cystic degeneration led to false diagnoses. In addition, necrosis and diffuse hypercellularity increased the suspicion of malignancy and led to classification of fine-needle aspirations as salivary gland neoplasm of uncertain malignant potential. CONCLUSION: The MSRSGC is useful in WT diagnostics, and it improves communication between cytopathologists and clinicians. In this study, the most useful cytomorphological feature that led to accurate WT diagnoses was papillary architecture in cell block specimens and the most significant pitfall was necrosis followed by diffuse hypercellularity.

• Klíčová slova
• Cell block, Cytomorphology, Milan System for Reporting Salivary Gland Cytopathology, Salivary glands, Warthin’s tumour,
• MeSH
• adenolymfom * patologie   diagnóza   MeSH
• dospělí MeSH
• falešně negativní reakce MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nádory slinných žláz * patologie   diagnóza   MeSH
• prediktivní hodnota testů MeSH
• reprodukovatelnost výsledků MeSH
• retrospektivní studie MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• tenkojehlová biopsie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH