The Contributory Role of Cell Blocks in Salivary Gland Neoplasms Fine Needle Aspirations Classified by the Milan System for Reporting Salivary Gland Cytology

Abstract

(1) Background: The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was introduced in 2018, bringing an organ-specific classification system for salivary gland cytopathology. The aim of present study is to evaluate the MSRSGC prospectively, based on a two-year experience in the tertiary care center pathology department, and evaluate the role of routine cell block (CB) preparation in salivary gland cytopathological diagnostics. (2) Methods: In our institution, the Department of Pathology, Fimlab Laboratories, Tampere, Finland, the MSRSGC has been implemented in salivary gland cytopathology since January 2018 and, over a two-year period (January 2018–December 2019), there were 365 fine-needle aspirations, of which 164 had a surgical follow-up. The CB methods used were Plasma-thrombin, the collection of visible fragments, and the Shandon and in-house methods. (3) Results: The MSRSGC diagnostic figures were as follows: accuracy 87.5%, sensitivity 45.8% and specificity 98.9%. For diagnostic categories of MSRSGC (non-neoplastic, benign neoplasm and malignant neoplasm) (n = 63) diagnostic accuracy was 98.4%, and for undetermined categories (atypia of undetermined significance, salivary gland neoplasm of uncertain malignant potential and suspicious for malignancy) (n = 49) diagnostic accuracy was 73.5%. Non-contributory cell blocks resulted more often in a false negative diagnosis (25%, 3/12) than a true negative diagnosis (10%, 7/73, p < 0.001), and is, most likely, an insufficient cytological diagnosis (86%, 18/21, p < 0.001). (4) Conclusion: The application of MSRSGC and CBs are beneficial in salivary gland cytological diagnosis, increasing diagnostic accuracy and, thus, patients’ management and treatment.

Application of the Milan System for Reporting Salivary Gland Cytopathology: A systematic review and meta‐analysis

“…After reviewing the titles and abstracts, 54 articles were excluded. The full texts of the remaining 80 articles were reviewed, and 35 articles 5–39 were finally included in the systematic review and meta‐analysis.…”

“…After reviewing the titles and abstracts, 54 articles were excluded. The full texts of the remaining 80 articles were reviewed, and 35 articles 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 were finally included in the systematic review and meta‐analysis.…”

“… 9 , 15 , 25 , 39 In 7168 FNAs, the diagnoses had histological follow‐up. Twenty‐one studies 8 , 9 , 10 , 12 , 13 , 14 , 15 , 16 , 17 , 19 , 20 , 23 , 24 , 25 , 26 , 29 , 31 , 33 , 34 , 38 , 39 comprised 6366 consecutive FNA samples, including 2828 cases with histologic follow‐up. As reported in the demographic data, the mean patient age was 54.4 years, and the female‐to‐male ratio was 0.91:1.…”

“…Two studies were performed prospectively, 11 , 31 whereas the rest were retrospective except for one multicenter study that assigned cases prospectively or retrospectively. 36 According to the research origin (sorted by the International Monetary Fund 40 ), 19 studies were from developed countries, and 16 were from developing countries.…”

Cyto-Histopathological Correlations in Pathology Diagnostics

“…The contributory role of cell blocks (CBs) in salivary gland cytology classified according to The Milan System for reporting Salivary Gland Cytology (MSRSGC) was demonstrated by Tommola et al [ 11 ]. The application of MSRSGC and CBs was found beneficial in a series of 365 fine needle aspiration specimens from a 2-year-period with an increase in diagnostic accuracy, and thus improving the patients´ treatment and management [ 11 ].…”