Milan System For Reporting Salivary Gland Cytopathology Research Articles

The indeterminate categories of the Milan system for reporting salivary gland cytopathology (MRSGC): A minireview

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC), first published in 2018, attempted to develop a standardized and objective system of reporting salivary gland fine needle aspiration smears. It was widely accepted by the cytopathologists who started using it in their day-to-day practice. With the publication of new literature, the Milan system was updated and the 2 edition was released in 2023. The 5 WHO classification of salivary neoplasms, ancillary tests, and imaging characteristics of various salivary neoplasms have also been highlighted in the new edition. The 3 indeterminate categories of the Milan system of reporting are the atypia of undetermined significance (AUS), salivary gland tumor of undetermined malignant potential (SUMP), and suspicious for malignancy (SM) that create major dilemmas for the reporting cytopathologists. The present minireview highlights the criteria of diagnosis and further workup of the various lesions in these categories.

How the Milan System for Reporting Salivary Gland Cytopathology works in cytopathology practice: Meta-analysis of prospective studies and comparison with retrospective studies.

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is widely accepted and endorsed by professional societies. Although several studies focusing on the MSRSGC have been published, few have been prospective studies. The objective of this study was to evaluate the effectiveness of the MSRSGC in cytopathology practice. A comprehensive literature search was conducted to identify all prospective studies on the MSRSGC. The risk of malignancy (ROM), risk of neoplasm, and diagnostic accuracy for each diagnostic category were calculated. Data were tabulated in Microsoft Excel, and analyses were performed with the Open Meta-Analyst program. Seven prospective and seven retrospective studies were identified. The total number of fine-needle aspirations (FNAs) was 1587 in the prospective studies and 1764 in the retrospective studies. The ROM values for the nondiagnostic, nonneoplastic, atypia of undetermined significance, benign neoplasm, salivary gland neoplasm of uncertain malignant potential, suspicious for malignancy, and malignant categories in prospective versus retrospective studies were 21.0% versus 26.6%, 9.4% versus 8.1%, 34.9% versus 39.6%, 2.4% versus 2.1%, 36.6% versus 31.2%, 86.0% versus 66.0%, and 97.0% versus 96.7%, respectively. Sensitivities, specificities, and diagnostic odds ratios were 83.1% (95% confidence interval [CI], 71.1%-90.8%) versus 89.1% (95% CI, 83.6%-92.9%), 98.4% (95% CI, 96.6%-99.3%) versus 94.9% (95% CI, 91.9%-96.9%), and 310.7 (95% CI, 121.2-796.6) versus 218.8 (95% CI, 107.3-438.1). This meta-analysis indicated that the MSRSGC works well in FNA cytopathology practice and improves diagnostic accuracy in all diagnostic categories. The ROMs of prospective studies were in concordance with the MSRSGC reference values.

Interobserver Reliability of Milan and Modified Milan System for Reporting Salivary Gland Cytopathology: An Institutional Experience

Background: In 2018, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was published, defining a diagnostic categorization scheme. However, this system of classification was criticized due to its suboptimal diagnostic accuracy and low interobserver reliability. For these reasons, the modified Milan system was recently proposed by a few authors claiming it to be more clinically reliable. The present study aimed to analyze the interobserver reliability of MSRSGC and modified MSRSGC. Methods: A total of 100 salivary gland fine-needle aspirations were reviewed over a 1-year period and classified by two independent observers according to MSRSGC and modified MSRSGC. Interobserver reproducibility was estimated using observed agreement and chance-corrected agreement (Cohen’s kappa). Results: An overall chance corrected agreement of 0.37 (fair) was obtained for the original Milan system and 0.41 (moderate) for the modified one. In addition, subcategories of modified MSRSGC performed better than the MSRSGC in terms of interobserver reliability. Conclusion: The present study suggests that modified MSRSGC should be accepted worldwide as the clinical relevance of any categorization scheme requires diagnostic accuracy along with excellent interobserver reproducibility.

Rapid on-site evaluation improves diagnostic performance of fine-needle aspiration cytology for salivary lesions: Comparison of data from two cancer centers in southern China.

To evaluate the diagnostic performance of Milan system for reporting salivary gland cytopathology (MSRSGC) in two southern China tertiary cancer centers and investigate the impact of rapid on-site evaluation (ROSE) on FNAC performance. Five hundred and forty-nine patients who underwent FNAC for salivary lesions with surgical follow-up from two centers were enrolled in this retrospective cohort study. All slides were recategorized using MSRSGC after consensus on diagnostic criteria for each category. The diagnostic performance of FNAC for salivary lesions was evaluated and compared and the impact of ROSE on FNAC performance was analyzed. The distribution of cases per category based on the MSRSGC criteria in the whole series was as followed: ND 49 (8.9%), NN 76 (14.4%), BN 262 (47.7%), AUS 20 (3.6%), SUMP 43 (7.8%), SM 21 (3.8%), M 78 (14.2%). The SUMC series had significantly more ND distributions than JXCH did (16.2% vs. 0, p = .000). Risk of malignancy for each category in the total series was as followed: 42.9% for ND, 9.2% for NN, 3.8% for BN, 30.0% for AUS, 23.3% for SUMP, 81.0% for SM, and 94.9% for M. When ND and AUS/SUMP were excluded, the sensitivity, specificity, PPV, NPV, and accuracy were 84.0%, 97.1%, 89.9%, 95.1%, and 94.0%, respectively; sensitivity, specificity, PPV, NPV, and accuracy were comparable between the two centers. FNAC using MSRSGC provides a good tool in preoperative evaluation for salivary lesions in southern China. ROSE improves its diagnostic performance by reducing the ratio of the ND category.

Importance of radio-histo-cytopathological correlation, A retrospective study of cyto-histological and radiological correlation of salivary gland lesions using Milan System for Reporting Salivary Gland Cytopathology

ABSTRACT Background: Fine-needle aspiration cytology (FNAC) for salivary gland tumors can be challenging to due to the diversity of lesions and cytomorphological convergence between the tumors. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was hence developed and introduced to provide enhanced communication in salivary gland cytopathology. To evaluate the diagnostic utility and validity of MSRSGC in combination with ancillary radiological investigations, we aim to find correlation between Milan system and the radiological impression comparing with final histopathological diagnosis. Aims and Objective: Correlate the Milan category with the radiological and final histopathological diagnosis of salivary gland lesions. Review the FNAC diagnosis of salivary gland lesions and identify cytomorphological predictors of malignancy. Correlate the FNAC and the radiological diagnosis with final diagnosis in histopathology. Material and Methods: A five year retrospective study, comprising fifty four cases of salivary gland FNAC were included in the study. Results: Majority of the cases belong to Milan VI—Malignant followed by Milan IVa—Benign and rest of cases were among other categories. The sensitivity, specificity, positive predictive value, and negative predictive value of adjuvant radiological diagnosis in differentiating benign and malignant salivary gland lesions was found to be 80%, 62.5%, 72.7%, and 71.4%, respectively. We could observe that the concurrent radiological assessment along with Milan system of reporting in salivary gland FNAC especially under suspicious categories (Milan Category IVb as well as Milan Category V) is a useful and sensitive predictor of malignancy. Conclusion: A correlation with any form of ancillary radiological assessment is a helpful adjuvant with Milan system to derive a relatable diagnosis in salivary gland neoplasm especially those in categories describing the suspicious entities.

Utility of the Milan System for Reporting Salivary Gland Cytopathology in Parotid Gland Masses: The Experience of Two Tertiary Centers.

Background The application of fine needle aspiration (FNA) in parotid masses via the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) enhances the diagnosis of these lesions alongside radiological investigations. Objectives Our objective was to assess the risk of malignancy, sensitivity, specificity, and false positive and negative results for each category of the MSRSGC. Additionally, we assessed the level of agreement between the FNA results using MSRSGC and post-resection histopathological diagnosis. Methods We conducted a retrospective chart review of parotid gland masses that received FNA and postoperative pathological diagnosis at King Saud University Medical City and King Fahad Medical City between 2018 and 2022. We summarized the categorical variables using frequencies and percentages. Results A total of 172 cases met the inclusion criteria. Males encompassed 102 patients (59.3%) of the study sample, and 89 (51.7%) of parotid masses were on the left side. The risk of malignancy for the MSRSGC categories was 37.5% (Category I), 9.0% (II), 50.0% (III), 4.7% (IVa), 50.0% (IVb), 100.0% (V), and 71.0% (VI). FNA had an overall success rate of 81%. The sensitivity was 64% and specificity was 94% for non-neoplastic masses. For benign masses, the sensitivity was 91% and specificity was 66%; however, the sensitivity was 40% and specificity was 97% for malignant lesions. We found that the percentage of agreement between the FNA and final pathology was 80%. Conclusion FNA using MSRSGC is a valuable preoperative clinical tool. However, the low sensitivity rates based on the diagnosis of malignant lesions should alert clinicians not to be overly reliant on biopsy results and instead defer to definitive surgical management.

Second edition of the Milan System for Reporting Salivary Gland Cytopathology: Refining the role of salivary gland FNA.

The use of standardized reporting systems for non-gynecologic cytopathology has made enormous gains in popularity during the past decade, including for thyroid fine-needle aspiration, urine cytology, serous effusions, pancreas, lymph nodes, lung, and more. In February 2018, the first edition Atlas of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was published. The MSRSGC defines six diagnostic fine-needle aspiration categories encompassing the spectrum of non-neoplastic, benign, and malignant lesions of the salivary glands. The goal of the MSRSGC is to combine each diagnostic category with a defined risk of malignancy and a specific clinical and/or surgical management algorithm. Since its initial publication in 2018, more than 200 studies and commentaries have been published confirming the role of the MSRSGC. The second edition of the MSRSGC, published in July 2023, includes refined risks of malignancy based on systematic reviews and meta-analyses, a new chapter summarizing the use of salivary gland imaging, new advances in ancillary testing, and updates in nomenclature.

Second edition of the Milan System for Reporting Salivary Gland Cytopathology: Refining the role of salivary gland FNA.

The use of standardised reporting systems for non-gynaecologic cytopathology has made enormous gains in popularity during the past decade, including for thyroid fine-needle aspiration, urine cytology, serous effusions, pancreas, lymph nodes, lung and more. In February 2018, the first edition of the Atlas of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was published. The MSRSGC defines six diagnostic fine-needle aspiration categories encompassing the spectrum of non-neoplastic, benign and malignant lesions of the salivary glands. The goal of the MSRSGC is to combine each diagnostic category with a defined risk of malignancy and a specific clinical and/or surgical management algorithm. Since its initial publication in 2018, more than 200 studies and commentaries have been published, confirming the role of the MSRSGC. The second edition of the MSRSGC, published in July 2023, includes refined risks of malignancy based on systematic reviews and meta-analyses, a new chapter summarising the use of salivary gland imaging, new advances in ancillary testing and updates in nomenclature.

The Milan System for Reporting Salivary Gland Cytopathology: the experience of a tertiary cancer center with emphasis on non-mucinous cysts and improving diagnostic results

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was introduced in 2018 to standardize cytology reporting and guide patient treatment. We aimed to evaluate the utility of this system applied to patients at our cancer center. We retrospectively reviewed cases of salivary gland fine-needle aspirations (FNAs) performed in our institution (2019-2022). All were performed by radiologists and immediately assessed for specimen adequacy. The cytologic findings were classified into the MSRSGC except for non-mucinous cystic contents (NMCC) where the lesion was radiologically consistent with a cyst and totally collapsed after FNA. Such lesions were categorized as non-neoplastic (NN) instead of non-diagnostic (ND). The cytologic findings were compared to corresponding histologic findings (212 available cases), and the risk of malignancy was calculated. Five hundred five FNAs were categorized as: 25 (4.95%) ND; 86 (17.03%) NN, of which 39 were NMCC; 9 (1.78%) atypia of undetermined significance; 138 (27.33%) benign neoplasms; 57 (11.29%) salivary gland neoplasm of undetermined malignant potential; 16 (3.17%) suspicious for malignancy; and 174 (34.46%) malignant. The risk of malignancy rates for the following categories were: ND, 40%; NN, 25%; atypia of undetermined significance, 0%; benign neoplasms, 1%; salivary gland neoplasm of undetermined malignant potential, 54.54%; suspicious for malignancy, 90.9%; and malignant, 100%. Thirty-one NMCC with available follow-up resolved/remained stable. Our results validate the reproducibility of the MSRSGC applied in our cancer center. Based on the benign course of cysts with NMCC, we propose that such cases be categorized as NN, provided the cyst is totally resolved after FNA.

Prioritizing parotid gland surgery: A call for the implementation of the MSRSGC classification.

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is developed to aid diagnosis and management of salivary gland tumors. This study evaluates the time-to-treatment initiation (TTI) for parotid gland tumors in the Netherlands and relates these to the MSRSGC classification. Subsequently, the use of the MSRSGC in the Netherlands is evaluated. Data regarding fine-needle aspiration cytology (FNAC) and histopathological resections of the parotid were gathered from the Dutch nationwide pathology data bank (PALGA). The TTI was calculated for each MSRSGC category and type of treating center. FNACs performed from 2018 to 2021 were gathered from PALGA to estimate how frequently the MSRSGC classification was applied. Median TTI in days were 86 for nondiagnostic (MSRSGC I), 75 for nonneoplastic (MSRSGC II), 65 for atypia of unknown significance (AUS) (MSRSGC III), 89 for benign (MSRSGC IVa), 52 for salivary gland neoplasm of unknown malignant potential (SUMP) (MSRSGC IVb), 31 for suspected malignant (MSRSGC V), and 30 for malignant (MSRSGC VI) categories. Significant variation in the TTI between the types of treating centers was found for the nondiagnostic, nonneoplastic, AUS, SUMP, and suspected malignant categories. In the first 3 years after the introduction of the MSRSGC, the pathologist stated the MSRSGC classification in 6.4% of all reports. The median TTI for most categories is long, and there is significant interhospital variation in TTI. Preoperative risk stratification and treatment prioritization in parotid gland surgery in the Netherlands should be improved. The MSRSGC could contribute to this. Until 2021, the MSRSGS classification was implemented on a limited scale in the Netherlands.

Evaluation of Fine Needle Aspiration Cytopathology in Salivary Gland Tumors under Milan System: Challenges, Misdiagnosis Rates, and Clinical Recommendations.

(1) Background: Salivary gland tumors are rare in the head and neck. To determine the need and extent of surgical intervention, fine needle aspiration (FNA) is a widely accepted tool to approach salivary gland lesions. However, the FNA cytology varies between entities, while the lack of uniform terminology makes diagnosis more challenging. Since establishing the Milan system for reporting salivary gland cytopathology (MSRSGC) has become an increasingly accepted reporting standard, further examination and detailed recommendations were needed. (2) Methods: Between April 2013 and October 2021, 375 cases with FNA and salivary gland resection were retrospectively collected. All FNA specimens were reclassified according to the criteria of MSRSGC. After surgical excision, the FNA data were compared with the histological diagnosis to estimate the risk of malignancy (ROM), the risk of neoplasm (RON), and the diagnostic accuracy for each diagnostic category. (3) Results: Our cohort's distribution of ROM and RON was similar to the MSRSGC's recommendation. Carcinoma ex pleomorphic adenoma (CXPA) has the highest rate (66.7%) of misdiagnosed as a nonneoplastic lesion or benign salivary gland tumor. Pleomorphic adenoma (PA) and Warthin's tumor were the most common benign salivary gland tumors, while the cytology diagnosis of Warthin's tumor seems more challenging than PAs. (4) Conclusions: Despite the convenience and effectiveness of MSRSGC, we suggest close follow-up, re-biopsy, or surgical removal for salivary lesions even in Milan IVA-Benign for possibly missing FNA of malignancy, mixed lesions, or prevention of malignant transformation.

Cytopathological Spectrum of Salivary Gland Lesions According to Milan Reporting System: A Retrospective Study

Background: The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was developed in 2015 to standardize reporting of salivary gland cytology, promote better communication between clinicians and institutions, and ultimately improve patient outcomes care. The current study aims to determine the cytopathological spectrum of salivary gland lesions using the Milan System for reporting in a tertiary care hospital of northeast India. Methods: Clinical data and cytology smears of salivary gland lesions diagnosed from January 2016 to May 2021 were retrieved. All the cytology smears were reviewed again and reclassified to one of the six categories after applying strict criteria given by MSRSGC. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of FNAC to detect malignant lesions were calculated considering HPE as the gold standard. Results: A total of 57 salivary gland lesions were examined, 31 (54.38%) were males, and 26 (45.6%) were females with a median age of 34 years (range 6-70 years). Statistical analysis showed the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy as 75%, 100%, 100%, 95%, and 95.65%, respectively. MSRSGC Category IVa was the commonest with 29 cases of pleomorphic adenoma. Conclusion: The overall diagnostic accuracy of cytologic reporting of salivary gland lesions based on Milan nomenclature in our institution was 95.65%. Our findings reflect the positive contribution of the MSRSGC towards accurately identifying the malignant lesions and thus further helping the clinicians regarding the specific management decisions.

Comparison Study of FNAC Using the Milan System Cytopathology versus Definitive Histology for the Diagnosis of Salivary Gland Tumors

Introduction: Salivary gland tumors (SGT) represent 6 to 8 percent of head and neck tumors. The cytologic diagnosis of SGT is performed by fine-needle aspiration cytology (FNAC) with variable sensitivity and specificity. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) categorizes the cytological results and provides the risk of malignancy (ROM). The aim of our study was to evaluate the cytological findings with the definitive pathological findings to assess the sensitivity, specificity, and diagnostic accuracy of FNAC in SGT according to MSRSGC classification. Method: An observational, retrospective, single-center study was carried out at a tertiary referral hospital over a period of 10 years. Patients that underwent FNAC for major SGT and that have undergone surgery to remove the tumor were included. A histopathological follow-up was performed on the surgically excised lesions. Results from the FNAC were categorized into one of the six MSRSGC categories. The sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy of FNAC for determining benign and malignant cases were calculated. Results: A total of 417 cases were analyzed. The cytological prediction of ROM was 10% in nondiagnostic, 12.12% in non-neoplastic, 3.58% in neoplasm benign group, 60% in AUS and SUMP groups, and 100% in suspicious and malignant group. The statistical analysis of sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for determining benign cases was 99%, 55%, 94%, 93%, and 94%, respectively, and for determining malignant neoplasm was 54%, 99%, 93%, 94%, and 94%, respectively. Conclusion: In our hands, MSRSGC is highly sensitive for benign tumors and highly specific for malignant tumors. The low sensitivity to differentiate malignant from benign cases makes it necessary to apply an adequate anamnesis, physical examination, and imaging tests to consider surgical treatment in most cases.

Update on Salivary Gland Fine-Needle Aspiration and the Milan System for Reporting Salivary Gland Cytopathology.

Fine-needle aspiration (FNA) is a well-established procedure for the diagnosis and management of salivary gland lesions, despite challenges imposed by salivary gland tumor diversity, complexity, and cytomorphologic overlap. Until recently, the reporting of salivary gland FNA specimens was inconsistent among different institutions throughout the world, leading to diagnostic confusion among pathologists and clinicians. In 2015, an international group of pathologists initiated the development of an evidence-based tiered classification system for reporting salivary gland FNA specimens, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC). The MSRSGC consists of 6 diagnostic categories, which incorporate the morphologic heterogeneity and overlap among various nonneoplastic, benign, and malignant lesions of the salivary glands. In addition, each MSRSGC diagnostic category is associated with a risk of malignancy and management recommendations. To review the current status of salivary gland FNA, core needle biopsies, ancillary studies, and the beneficial role of the MSRSGC in providing a framework for reporting salivary gland lesions and guiding clinical management. Literature review and personal institutional experience. The main goal of the MSRSGC is to improve communication between cytopathologists and treating clinicians, while also facilitating cytologic-histologic correlation, quality improvement, and research. Since its implementation, the MSRSGC has gained international acceptance as a tool to improve reporting standards and consistency in this complex diagnostic area, and it has been endorsed by the 2021 American Society of Clinical Oncology management guidelines for salivary gland cancer. The large amount of data from published studies using MSRSGC served as a basis for the recent update of the MSRSGC.

Salivary gland fine-needle aspiration biopsy: quality assurance results from a tertiary cancer center.

Fine-needle aspiration biopsy (FNAB) plays a critical role in the management of patients with salivary gland lesions. A specific diagnosis can be difficult due to the wide range of lesions with overlapping morphologic features, potentially leading to interpretation errors. We analyzed the cytologic-histologic discrepancies identified in the quality assurance program of a major cancer center in cases of salivary gland FNAB and performed a root cause analysis. Salivary gland FNAB specimens performed during a 12-year period at a major tertiary cancer center were reviewed. The inclusion criteria for this study included FNAB cases of salivary glands with subsequent histologic or flow cytometry follow up. The cytologic diagnoses for these cases were recategorized according to the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) based on the original reports. The risk of neoplasm and malignancy based on the cases with subsequent resection or flow cytometry and the most common causes of discrepancy were analyzed. The risk of neoplasm ranged from 41% to 99% and the risk of malignancy ranged from 22% to 99% among the different MSRSGC categories. Lymphoid and myoepithelial rich lesions were the most common miscategorized lesions using the MSRSGC. Reactive changes due to inflammation were associated with overcalls. The most common malignancy in the atypical category was mucoepidermoid carcinomas. Myoepithelial and lymphoid rich lesions arising in the salivary gland are associated with a higher risk of misclassification. The use of category IVB in the MSRSGC is appropriate for lesions with abundant myoepithelial cells. Reactive atypia seen in sialadenitis was the most common feature associated with overcall.

The Milan system for reporting salivary gland cytopathology-A single-center study of 2156 cases.

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. 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. 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%. 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.

Assessment of Risk of Malignancy of Fine-needle Aspiration Cytology in Salivary Gland Lesions Using the Milan System for Reporting Salivary Gland Cytopathology Categorization: A Systematic Review and Meta-analysis.

Fine-needle aspiration cytology (FNAC) of the salivary gland is crucial in the identification of salivary gland lesions, but the variation in morphological pattern and the overlap of morphological traits can result in erroneous interpretation and affect treatment, making FNAC of the salivary gland problematic. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was created to address these problems. To ascertain whether the FNAC method using MSRSGC was reliable in predicting the risk of malignancy (ROM) in each category of salivary gland lesions. The databases PubMed-MEDLINE, Web of Science, Cochrane, Scopus, and Google Scholar were all searched using pertinent keywords, reference searches, and citation searches. A fixed effect model was used to determine the pooled proportion with a 95% confidence interval (CI). All statistical analyses were performed using Meta Disc and R version 4.0.2 (R Foundation for Statistical Computing). After reviewing the submissions' abstracts and titles, 58 documents that satisfied the necessary inclusion and exclusion criteria were ultimately selected. A total of 19,652 samples from 19,408 individuals was analyzed, out of which 9,958 samples were available for histopathological follow-up. The pooled ROM for category I was 10%, category II was 5%, category III was 28%, category IV A was 2%, Category IV B was 34%, category V was 91%, and category VI was 99%. Milan System for Reporting Salivary Gland Cytopathology is useful for risk stratification and quality control, confirming its validity and diagnostic utility. Widespread use of MSRSGC would improve the accuracy of salivary gland cytology and lead to better patient care and improved treatment strategies. The results of this study are in consonance with reported values as per MSRSGC except for category V. The MSRSGC which was first reported in 2018 is a very useful tool for proper stratification of ROM in salivary gland FNAC. This study allowed us to validate the ROM values in different categories as reported in MSRSGC.

Cytohistological correlation and risk stratification of salivary gland lesions using the Milan System for Reporting Salivary Gland Cytopathology: A tertiary care centre experience.

Salivary gland neoplasms account for approximately 5% of head and neck tumours. The cytomorphology of fine needle aspiration material helps determine the preoperative assessment and risk stratification. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was developed to improve communication between the laboratory and treatment provider. In the present study, we stratified all salivary gland lesions according to the MSRSGC and evaluated each category's concordance and risk of malignancy (ROM). This was a 5 year retrospective study. First, all cases were assigned to one of the six MSRSGC categories. Then, following cytohistological correlation, the concordance rates and ROM were calculated based on the final histopathology report. A total of 354 cases were identified, with ages ranging from 2 to 88 years and the commonest age group was the 3rd to 4th decades. Categories I, II, III, IVA, IVB, V, and VI comprised 5.37% (19/354), 26.84% (95/354), 1.13% (04/354), 51.41% (182/354), 1.98% (07/354), 1.13% (04/354), and 12.15% (43/354) of the cases, respectively. The overall concordance rate between the cytological and histopathological diagnoses was 81.25% (65 out of 80 cases), with the sensitivity, specificity, positive predictive value, and negative predictive value at 43.48%, 96.49%, 83.33%, and 80.88%, respectively. The MSRSGC provides a better objective and structured way to communicate with the health care provider. In our study, the overall concordance rate was observed in 62/80 cases, with maximum concordance seen in categories III, IVB, and V of the MSRSGC.

Applicability of the Milan system for reporting salivary gland cytopathology: A single Brazilian institution experience.

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) emerged in 2015 as an attempt to establish protocols for a most appropriate follow-up and treatment of patients with salivary gland lesions. Through fine needle aspiration (FNA), a safe and minimally invasive way to obtain cytological samples, the lesion is classified into one of the six categories, which have different risks of malignancy (ROM) and, therefore, different management. FNA cytology procedures performed between January 2016 and June 2020 (54months) at the Pathology Institute of Araçatuba, São Paulo, Brazil, were analyzed by two pathologists with more than 5 years of experience. The ROM for each of the diagnostic categories was determines and compared with the ROM expected by the MSRSGC. A total of 99 FNA of salivary gland lesions were reviewed and retrospectively categorized. Histopathological follow-up was available for 58 of 96 patients (60.42%). The patients age ranged from 23 to 98 years with the mean of 58.15 ± 15.29 years. The parotid gland was the most affected (81.82%). The average size of the lesions was 2.59 cm. The ROM for each category was 16.67%, 0%, 0%, 2.86%, 50%, 100%, 100%, respectively. This is the first Brazilian study describing the application of the MSRSGC in the routine of a private Laboratory out of a cancer center service. Therefore, it is an effective method in the classification of salivary gland lesions, when associated with the MSRSGC, to determine the ROM and its appropriate treatment.

The diagnostic accuracy of pleomorphic adenoma in fine needle aspiration: Features leading to false positive and false negative diagnoses and the utility of cell blocks.

Fine needle aspiration (FNA) is a well-established tool in preoperative diagnosis of salivary gland lesions with diagnostic accuracy of 90%. Pleomorphic adenoma (PA) is the most common salivary gland tumor comprising 45%-74% of all salivary gland tumors with FNA diagnostic accuracy of 89.5%-96.2%. The aim of the present study was to determine and analyze potential cytomorphological pitfalls and evaluate the diagnostic accuracy in FNA diagnosis of PA. Salivary gland specimens with both cytological and histological diagnoses were searched over a 10-year-period (2009-2018) from a laboratory information system of Pathology Department, Fimlab Laboratories, Tampere and matched to determine concordant and discordant PA cases. Sufficient material in histological and cytological sample was found in 401 cases. In 218 cases (54.4%) diagnosis was true-negative PA, in 169 cases (42.1%) diagnosis was true-positive PA and there were 14 discordant cases: 4 false-positive cases and 10 false-negative cases. False-negative cases were reclassified and subgrouped according to The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC). Cytomorphologically, cell type predominance was more often myoepithelial in true-positive cases (65%) and epithelial both in false-negative (70%, p= .007) and false-positive cases (75%, p= .027). Well-formed ducts were present in cytology in all true-positive cases (p< .001). Only 10% of true-positive cases did not show any matrix in cytology (p< .001). Nuclear changes were common in false-negative cases (80%, p= .002) and false-positive cases (75%, p= .003). Beneficial cell block (CB) was more common in true-positive cases (85%) than in false-negative cases (50%, p= .041) or in false-positive cases (50%, p= .116) and a lack of beneficial CB led more often to a false diagnosis (70% false diagnosis without beneficial CB versus 29% false diagnosis with beneficial CB). The present study showed diagnostic accuracy of 96.5% for FNA in PA diagnosis. Sensitivity, specificity, positive predictive value and negative predictive value were 94.4%, 98.2%, 97.7%, and 95.6%, respectively. The benefit of CBs was more evident in true-positive cases (85%).