The impact of FNAC in the management of salivary gland lesions: Institutional experiences leading to a risk-based classification scheme

Oncologic outcomes of the most prevalent major salivary gland cancers: retrospective cohort study from single center

BACKGROUND

The preoperative diagnosis of salivary gland cancer (SGC) is crucial for the application of appropriate treatment, particularly involving the extension of the resection.

METHODS

Retrospective search of medical database identified 116 patients treated surgically with malignant tumors of salivary gland between 2010 and 2020. Analysis included the demographical data, clinical course, type of surgical and adjuvant treatment, histology type and margin status, perivascular invasion (LVI), perineural invasion (PNI), metastatic lymph nodes (LN). Facial nerve function, recurrence-free and overall survival were evaluated. Adequate statistics were used for data analysis.

RESULTS

The final cohort included 63 SGC patients, with adenoid cystic carcinoma the most common pathological type (27%, n = 17), followed by adenocarcinoma (17.4% n = 11). T1 and T2 patients accounted for majority cases (n = 46). The lymph node metastases were confirmed with the histopathology in 31.7% (n = 20). Distant metastases were observed in 4.8% of cases (n = 3). 38% (n = 24) of SGC were treated selectively with surgery, 49.2% (n = 31) had postoperative radiotherapy and 15.9% (n = 10)-radio-chemotherapy. The final facial nerve function was impaired in 38% of patients. Mean overall survival (OS) for all patients was 108.7 (± 132.1) months, and was the most favorable for acinar cell carcinoma (118.9 ± 45.4) and the poorest for squamous cell carcinoma (44 ± 32). Cox regression analysis of disease-free survival and OS identified significant association only with patients' age over 65 years, the hazard ratio of 7.955 and 6.486, respectively.

CONCLUSIONS

The efficacy of treatment modalities for SGC should be verified with regard to the histopathological type, but also the patients' age should be taken into account.

Implementation of the Milan System for Reporting Salivary Gland Cytology: A Two-Year Outcome Cytopathology Data of a Tertiary Care Center

OBJECTIVE

In 2015, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was implemented to eliminate overlapping and disparate morphologies in salivary gland lesions. This approach helps track diagnostic findings, describe the risk of malignancy for each group, and advance therapy based on the results. The research aimed to classify fine-needle aspiration (FNA) smears, analyze malignancy risk, correlate cytology with histological diagnosis, and reduce unnecessary surgeries.

METHODOLOGY

We evaluated 217 individuals using FNA, classified their conditions using the Milan System, and followed up on 149 cases through histopathology. Both the risk of malignancy in each cluster and the total risk of malignancy were noted.

RESULTS

The most recent studies, as reported by the MSRSGC, found almost universal agreement about this grouping. The FNA cytopathology test demonstrated a sensitivity of 75% for identifying salivary gland abnormalities and a specificity of 93.16%. The findings indicated that the test had an accuracy of 89.66%, with a positive predictive value of 72.41% and a negative predictive value of 93.97%.

CONCLUSION

The MSRSGC offers a standardized technique for examining the results and assists the physician in determining the treatment plan that will be most beneficial.

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.

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 nongynecologic 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. CONCISE SENTENCE: The second edition of the Milan System for Reporting Salivary Gland Cytopathology, 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, updates in nomenclature, and a guide to the practical application of the latest ancillary markers for the diagnosis of selected salivary gland fine-needle aspiration cases.

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.

Don't SUMP it! Utility of PLAG1 immunocytochemistry in basaloid SUMP subcategory

BACKGROUND

Basaloid salivary gland neoplasm of uncertain malignant potential (B-SUMP) is an indeterminate diagnostic subcategory, with pleomorphic adenoma (PA) representing the most common benign neoplasm. Pleomorphic adenoma gene 1 (PLAG1) staining is frequently seen in PAs and could aid in distinguishing them from other basaloid neoplasms. The authors evaluated the utility of PLAG1 immunocytochemistry (ICC) in differentiating PAs from other basaloid neoplasms in smears and liquid-based cytology (LBC) specimens.

METHODS

In total, 45 B-SUMP cytology aspirates and corresponding surgical excision specimens were identified. PLAG1 immunostaining was performed in all aspirates and surgical excision specimens and was scored as positive (strong/diffuse), equivocal (focal/weak), or negative.

RESULTS

PLAG1 ICC was performed directly on 38 smears and seven LBC specimens. PLAG1 was positive in 29 of 45 cases (64%), whereas six of 45 (13%) were equivocal, and 10 of 45 (22%) were negative. PLAG1-positive aspirates included 26 (90%) PAs, two (7%) basal cell adenomas (BCAs), and one (3%) carcinoma ex-PA. PLAG1-equivocal aspirates included four (67%) PAs and two (33%) BCAs, whereas negative aspirates included five (50%) BCAs, four (40%) adenoid cystic carcinomas, and one (10%) metastatic adenosquamous carcinoma. The sensitivity, specificity, positive, and negative predictive values were 87%, 86%, 93%, and 75%, respectively. Diagnostic accuracy was 87%.

CONCLUSIONS

PLAG1 ICC is useful when positive (strong/diffuse) and can be reliably performed on smears and LBC specimens. PLAG1 was positive in most PAs and in a small subset of BCAs. Therefore, in the absence of atypical cytologic features, PLAG1-positive tumors could be diagnosed as benign, with a note favoring PA versus BCA. In contrast, PLAG1-negative/equivocal tumors should remain in the B-SUMP category.

Diagnostic performance of inflammatory biomarkers and cytological analysis in salivary gland tumors

BACKGROUND

This study aimed to evaluate the diagnostic performance of serum inflammatory biomarkers in salivary gland tumors with dubious results following cytological analysis.

METHODS

A retrospective analysis of 239 cases following surgery between January 2011 and June 2022 was performed. Receiver Operating Characteristic curves were drawn and areas under the curves were computed to evaluate the diagnostic performance of the inflammatory biomarkers (SII, SIRI, PLR, and NLR). Optimal cut-offs for each marker were determined by maximizing the Youden index.

RESULTS

Analysis showed that among the major biomarkers examined, SIRI performed an AUC of 0.77. The best SIRI cut-off was 0.94 with an accuracy of 79.9%. The accuracy, sensitivity, and specificity of cytological analysis were 77.8%, 59.6%, and 90.7% respectively. By combining SIRI with cytological analysis we demonstrated an increase in sensitivity to 82.8%.

CONCLUSIONS

Inflammatory biomarkers could be evaluated to support the diagnosis and treatment of salivary gland tumors in difficult cases.

Milan system for reporting salivary gland cytology in diagnosis and surgery of parotid gland lesions

INTRODUCTION

A cytology report is always a challenge for both head and neck surgeons and cytopathologists to diagnose and manage parotid gland (PG) diseases, because of the various similar features between the lesions.

OBJECTIVES

The present study was conducted to assess our practice using the Milan System for Reporting Salivary Cytopathology (MSRSGC) and to evaluate the risk of malignancy (ROM) in different categories.

PATIENTS AND METHODS

The patients with parotid gland lesions were diagnosed by clinical examination, ultrasound, and FNAC under ultrasound guidance at our hospital from 1 May 2019 to 30 April 2021. The FNAC results were divided into six categories according to the Milan system. We calculated the ROM for each category of the Milan system based on histopathological follow-up.

RESULTS

This study included 204 patients. There were 115 men (56 %) aged 46-60 years. Pathology results were 33 cases for malignant and 182 cases for benign. The rate of malignancy for each category according to the MSRSGC were 23.1 % (non-neoplastic), 20 % (atypical), 50 % (neoplastic), 1 % (benign), 10.3 % (salivary neoplasm of uncertain neoplastic potential), 84.6 % (suspicious for malignancy), and 100 % (malignant) categories. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of FNAC with application of Milan system were respectively 90.9 %, 98.2 %, 90.9 %, 98.9 % and 97 %.

CONCLUSION

When the Milan system was applied, FNAC had a high efficacy, suggesting that MSRSGC can improve the communication between the cytopathologist and the surgeon. This system can allow the surgeon to decide the extent of the surgery.

A Report of Two Cases of Malignant Tumor of the Maxillary Sinus Diagnosed Using Fine-Needle Aspiration Cytology

Primary and metastatic malignancies arising in the sinuses are rare and histologically diverse. The role of fine-needle aspiration cytology (FNAC) and the cytomorphologic characteristics of these tumors have not been specifically addressed. We described two cases of suspected malignant maxillary sinus tumors in 85- and 90-year-old patients with comorbid conditions, both of whom underwent tissue biopsies that failed to yield a definitive diagnosis. We performed FNAC after imaging confirmed that the malignant tumors were outside the maxillary sinus. The 85- and 90-year-old patients were diagnosed with squamous cell carcinoma (SCC) and adenocarcinoma, respectively. In the latter, the cell block method was used to prepare the specimen, rendering individual cells identifiable. Atypia of the histological structure was confirmed without the influence of cell duplication, a known weakness of FNAC. Thus, the diagnosis was made quickly. We believe that FNAC would be utilized more frequently for the definitive diagnosis of sinonasal tumors as the technique and diagnostic technology improve further.

Oncocytic Salivary Gland Tumours: Cytological Features and Diagnostic Pitfalls

Oncocytes are epithelial cells having abundant eosinophilic cytoplasm. The presence of oncocytes in salivary glands pose a diagnostic challenge since they can be present in lesions ranging from non-neoplastic, benign to malignant. FNAC is a simple procedure which can aid in the pre-operative diagnosis of these lesions. This study is an eight year retrospective study in which salivary gland aspiration cytology cases having oncocytic cells and with available corresponding histopathology were included. These slides were reviewed for features like cellularity, presence of oncocytic cells, glandular elements, squamoid cells, nuclear atypia, mitosis, lymphoid tissue, necrosis. Twenty cases were included in the study. The mean age of presentation was 60 years showing male preponderance with parotid gland being the most common site of involvement. Concordant diagnosis on cytology and histopathology was seen in 16 cases and discordance was seen in 4 cases. All the discordant cases were reported as benign on cytology but on histopathology they were labelled as acinic cell carcinoma, squamous cell carcinoma, mucoepidermoid carcinoma and an intraparotid lymph node respectively. Review of discordant cases showed subtle findings like ill-formed acini, cytoplasmic vacuolation, goblet cells and dysplastic foci raising suspicion of a different diagnosis. The potential areas of pitfall and cause of discrepancy have been discussed in this study. It is crucial to be aware of the spectrum of lesions in which oncocytes are seen, to enable an accurate diagnosis on cytology. Careful evaluation of smears for subtle clues can minimize errors.

Fine-Needle Aspiration Cytology for Parotid Tumors

Fine-needle aspiration (FNA) cytology is widely used in clinical practice as a simple and minimally invasive test for parotid tumors that allows for preoperative estimation of benignancy and malignancy, histological type, and malignancy grade and can be performed on an outpatient basis. In recent years, cell blocks prepared with core needle biopsy (CNB) and liquid-based cytology (LBC) have increased the reliability of immunostaining and molecular biological testing, leading to improved diagnostic accuracy. In 2018, the Milan System for Reporting Salivary Gland Cytology was introduced, but it does not include malignancy grade or histological type, so we proposed the Osaka Medical College classification as a more clinically based cell classification that includes both types of information, and we have reported on its usefulness. This review gives an overview of the history and use of FNA and describes CNB and LBC and the two classification systems.

Comparisons among the Ultrasonography Prediction Model, Real-Time and Shear Wave Elastography in the Evaluation of Major Salivary Gland Tumors

We aimed to validate the diagnostic accuracy of a novel sonographic scoring model and compare it with other methods in the evaluation of malignant major salivary gland tumors. We enrolled 138 patients who received neck ultrasound (US) with fine needle aspiration (FNA) and further operations or core needle biopsies for major salivary gland tumors from June 2015 to October 2021. The sonographic scoring model was presented as 2.08 × (vague boundary) + 1.75 × (regional lymphadenopathy) + 1.18 × (irregular or speculated shape) + 1.45 × (absence of posterior acoustic enhancement) + 2.4 × (calcification). We compared the diagnostic accuracy of the sonographic scoring model with shear wave elastography (SWE), real-time elastography (RTE), and US-FNA cytology for differentiating between benign and malignant lesions. The sensitivity, specificity, and accuracy were 58%, 89%, and 85% for the sonographic scoring model, 74%, 62%, and 64% for the SD of SWE with optimal cutoff value of 31.5 kPa, 69%, 70%, and 70% for the 4-point scoring system of RTE, and 74%, 93%, and 91% for US-FNA cytology, respectively. The sonographic scoring model is feasible as assistance in the evaluation of major salivary gland tumors. US-FNA cytology remains the tool of choice in diagnosing malignant salivary gland tumors.

Validation of the Milan system for reporting salivary gland cytopathology: a single institution's 10-year experience

INTRODUCTION

Fine needle aspiration cytology is often used for the initial diagnosis and management of patients with salivary gland tumors. Because of its global usage, a consensus classification schema was devised in 2018 to initiate universal reporting of salivary gland cytology specimens, termed the Milan system for reporting salivary gland cytopathology (MSRSGC) and composed of distinct diagnostic categories. Few retrospective studies have been undertaken to review the MSRSGC within institutions.

MATERIALS AND METHODS

We analyzed salivary gland fine needle aspirations during a 10-year span from 2011 to 2021, categorized each cytology case to fit the MSRSGC, and subsequently reviewed the corresponding surgical resections, if indicated, to determine the rate of malignancy (ROM) and rate of neoplasia.

RESULTS

Our ROM was higher (>10%) for the following MSRSGC categories: non-neoplastic, atypia of undetermined significance, and suspicious for malignancy. Also, our data correlated well with the following MSRSGC categories: nondiagnostic, neoplasm-benign, salivary gland neoplasm of uncertain malignant, and malignant.

CONCLUSIONS

Although the data were indicative of the ROM for surgically resected salivary gland lesions, the ROM for non-neoplastic lesions could truly be lower given that most lesions in this category will not undergo surgical resection. Additionally, determination of the rate of neoplasia could a tool that could be used to further guide our clinical colleagues.

Nondiagnostic salivary gland FNAs are associated with decreased risk of malignancy compared with "all-comer" patients: Analysis of the Milan System for Reporting Salivary Gland Cytopathology with a focus on Milan I: Nondiagnostic

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) reports a 25% rate of malignancy (ROM) for the Milan I: Nondiagnostic (ND) category. We clarify the ROM of ND salivary gland fine-needle aspirations (SGFNAs) based on our institutional experience and review of the literature.

METHODS

Overall risk of malignancy (OROM) and that for those with surgical/flow cytometric follow-up (FROM) for each category and "all-comers" were calculated for Emory SGFNAs from January 2010 through March 2021. From a literature review of 50 articles using MSRSGC, distribution of diagnoses, rates of follow-up, FROM, and OROM by category were calculated. FROMs and OROMs between ND FNAs and all-comers were compared. Milan I rate was compared with the ratio of Milan I OROM to all-comer OROM.

RESULTS

Of 819 SGFNAs at Emory, 12.8% (n = 105/819) were ND. Thirty-two had known follow-up, with 12 (37.5%) being malignant. Nonmucinous cyst contents accounted for 26.7% of ND SGFNAs (n = 28/105); all 7 with surgical follow-up were benign. Of 50 MSRSGC studies, 18.2% (n = 2384/13,129) of SGFNAs were classified as ND, 26.6% (n = 635/2384) with known follow-up. Total FROM and OROM for ND FNAs (15.7% and 4.1%, respectively) were significantly lower than those for all-comers (24.9% and 11.4%, respectively) (p < .001). There was no relationship between rate of ND SGFNA and ND ROM.

CONCLUSIONS

The ND category is associated with a lower ROM than that of all-comer SGFNA patients. The "true" ROM for ND SGFNAs is likely best estimated by the 4.1% OROM. SGFNAs showing nonmucinous cyst contents have a particularly low ROM. Rate of ND SGFNAs does not influence ND ROM.

Management of malignant submandibular gland tumors: A 30-year experience from a single center

OBJECTIVE

Owing to histologic heterogeneity, biological behavior, and rarity, recommendations for the treatment of malignant submandibular gland tumors (MSGT) are inconsistent. The aim of this study was to present a single-center experience in the treatment of MSGT with an emphasis on surgical treatment, including indication on elective neck dissection (END).

STUDY DESIGN

Twenty-four MSGT were primary surgically treated (gland excision with neck dissection). Their records were retrospectively collected and analyzed.

RESULTS

The most frequent histology was adenoid cystic carcinoma (41.6%), followed by mucoepidermoid carcinoma (25%) and carcinoma ex pleomorphic adenoma (16.7%). There were 18 elective and 6 therapeutic neck dissections. Histopathologic examination confirmed 29% (7/24) of positive neck dissection specimens. The Kaplan-Meier analysis presented rates of disease-specific survival, disease-free survival, and overall survival (OS) of 81%, 78%, and 52% at 5 years, respectively. Patients undergoing postoperative radiotherapy had significantly higher OS rates compared with patients treated with surgery alone (P = .0209).

CONCLUSION

Results of this study suggest that END has questionable benefit in early stage MSGT. Elective selective neck dissection levels I-III is recommended in high-grade and advanced stage MSGT without evidence of multilevel lymphadenopathy.

Atypia of undetermined significance in the Milan System for Reporting Salivary Gland Cytopathology: Cystic versus non-cystic masses

The term "Atypia" has been employed to describe a wide spectrum of cytomorphologic features associated with reactive/inflammatory processes as well as those suspicious for neoplasms in cytology. Similar to other cytopathology reporting systems, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has reserved the atypical category for cytology specimens lacking quantitative and/or qualitative cytomorphologic features to be diagnosed with confidence as either non-neoplastic or neoplastic. In MSRSGC, the atypical category is associated with a risk of malignancy and recommendation for clinical management. In this review, we discuss the value of atypical diagnostic category of MSRSGC in both cystic and non-cystic salivary gland lesions by evaluating our institutional case cohort.

Reclassification of salivary gland aspirates based on “The Milan system for reporting salivary gland cytology”: A five-year retrospective study

Introduction:

The Milan System for reporting salivary gland cytopathology helps standardize reporting systems across institutions, improve communication between clinicians and pathologists and guide the clinical management of patients.

Aims:

This study was undertaken to evaluate the utility of the Milan system classification in cytology reporting.

Settings and Design:

The present study is a retrospective study conducted over a period of five years in tertiary care centre.

Methods and Materials:

All the cases of salivary gland aspirates were reviewed and reclassified into six diagnostic categories according to the Milan system of reporting salivary gland cytology (MSRSGC). Cytological diagnosis was correlated with the histopathological diagnosis wherever available.

Results:

A total of 258 cases were classified using the Milan system as non-diagnostic (20.9%), non-neoplastic (26.3%), atypia of undetermined significance (4.7%), neoplasm benign (37.5%), neoplasm of uncertain malignant potential (3.5%), suspicious for malignancy (0.4%), and malignancy (6.6%). Cytohistological discordance was noted among 8/76 cases (10.5%). The sensitivity and specificity of FNAC were 75% and 98.5%, respectively. The risk of malignancy was 14.2% for Category I, 9% for II, 50% for III, zero for IVA and IVB, and 83.3% for category VI.

Conclusions:

The new classification system helps pathologists to standardize reporting leading to better clinical and surgical management.

Fine-Needle Aspiration Cytology of Salivary Gland Tumors Before the Milan System: Ten Years of Experience at a Tertiary Care Center in Turkey

Objective

The role of fine-needle aspiration cytology (FNAC) is well established for preoperative evaluation of patients with salivary gland lesions. However, the lack of a uniform system for salivary gland FNAC has limited its effectiveness. In recent years, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has been in use around the world to report the cytology results. We aimed to investigate the efficacy and accuracy of FNAC examined according to pre-MSRSGC era dichotomous benign/malignant classification in salivary gland tumors.

Methods

Patients who underwent surgery between January 2011 and December 2020 due to major salivary gland tumors were retrospectively analyzed. Two hundred and four patients were included in the analysis. Preoperative FNAC results and final histopatological diagnoses were grouped as benign or malignant. Final histopatological diagnoses were compared with the preoperative FNAC results. Also, sensitivity, specificity, and accuracy of the preoperative FNAC results, as well as the agreement between both tests were investigated.

Results

The sensitivity, specificity, accuracy, positive and negative predictive values of the preoperative FNAC for the diagnosis of malignancy were 59.09%, 97.85%, 93.75%, 76.47%, and 95.29%, respectively. There was a moderate agreement between the preoperative FNAC results and final histopatological diagnoses.

Conclusion

The accuracy of the preoperative FNAC and the information given about malignancy risk are the most important criteria for patient management and decision-making. The MSRSGC, which consists of a six-tiered classification rather than a dichotomous "yes/no" system, may contribute to patient management and decision-making by increasing the efficacy and accuracy of FNAC.

Utility of the Milan System for Reporting Salivary Gland Cytology, with focus on the incidence and histologic correlates of atypia of undetermined significance (AUS) and salivary gland neoplasm of uncertain malignant potential (SUMP): A 3-year institutional experience

BACKGROUND

Fine-needle aspiration (FNA) is the preferred diagnostic test for salivary gland lesions. The purpose of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is to standardize salivary gland cytology reporting and guide treatment decisions. The objective of the current study was to evaluate the utility and performance of the MSRSGC, with a focus on the cytomorphology of lesions diagnosed as atypia of undetermined significance (AUS) and salivary gland neoplasm of uncertain malignant potential (SUMP).

METHODS

In total, 123 salivary gland FNAs were included in the study. FNA diagnoses for all cases were reviewed and recategorized, as applicable, according to the MSRSGC. Cytohistologic correlation was performed in 51 cases that had available surgical follow-up, and the risk of malignancy (ROM) was calculated.

RESULTS

Most FNA samples were from the parotid gland. The mean patient age was 61.4 years, and the male-to-female ratio was 1.3:1. The ROM was 0% (categories I and II; nondiagnostic and benign nonneoplastic, respectively), 50% (category III; AUS), 0% (category IVA; benign neoplasm), 40% (category IVB; SUMP), 100% (category V; suspicious for malignancy), and 100% (category VI; malignant). Sensitivity, specificity, positive predictive value, and negative predictive value were 100% each. In addition, the primary factors for an AUS diagnosis were identified as low cellularity and/or the presence of lymphocytes. The presence of oncocytes followed by cellular atypia in an otherwise classic pleomorphic adenoma were principal factors for a SUMP diagnosis.

CONCLUSIONS

The authors report an ROM comparable to that reported in the literature, with a sensitivity and specificity of 100%, supporting adaptation of the MSRSGC into the system for reporting salivary gland cytology. In addition, the findings emphasize the need to refine criteria for AUS and SUMP, thereby improving the predictive capability and subsequent management of salivary gland lesions.

Risk stratification by application of Milan system for reporting salivary gland cytopathology: A tertiary care experience

Objectives:

The Milan system for reporting salivary gland cytopathology (MSRSGC) classification has been proposed to improve reproducibility in the management of salivary gland lesions. Fine-needle aspiration cytology (FNAC) is a widely accepted, well-tolerated, cost-effective, minimally invasive diagnostic method for pre-operative evaluation of salivary gland lesion that aids management decisions. The present study aims to reclassify the salivary gland FNAC aspirates by applying MSRSGC and calculating the risk of neoplasm and malignancy for each diagnostic category.

Material and Methods:

The present study is a retrospective observational study done for 54 months. A total of 168 cases of salivary gland FNA, 54 cases were excised in our institute for histopathology. Retrospective reviews were performed, and the FNAC cases were reclassified according to the Milan system, and the results of FNAC and final histology were correlated, wherever available. Furthermore, the risk of malignancy was calculated for all the diagnostic categories. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy (DA) of FNAC were determined.

Results:

In the present study, the age of patients ranged from 3 to 86 years, with a mean age of 39 years. Among all the patients, 61.3% were male, and 38.6% were female. However, only 54 salivary gland FNA samples for which histopathology was available were categorized into six categories. Among them, category IV (neoplastic) had a maximum number of cases of 66.6%. The rate of malignancy was calculated for all diagnostic categories as follows: (1) Non-diagnostic: 0.0%, (2) non-neoplastic 0.0%, (3) atypia of undermined significance 100%, (4a) benign 5.5%, (4b) uncertain malignant potential 33.33%, (5) suspicious for malignancy 00%, and (6) malignancy 80%. The sensitivity, specificity, PPV, NPV, and DA for differentiating between benign and malignant neoplasm were 36.3%, 94.4%, 66.6%, 82.9%, and 80%. Two false-positive and seven false-negative neoplastic cases were noted.

Conclusion:

FNAC is a reliable, minimally invasive diagnostic method with high DA for diagnosing salivary gland lesions. Most salivary gland lesions can be accurately diagnosed on FNAC with adequate sampling and cytopathologists experience.

Cytopathology and diagnostics of Warthin's tumour

Warthin's tumour (WT) is a benign epithelial salivary tumour, one type of salivary adenoma. Histologically, WT is structured of two components, epithelial tissue that often lines cystic formations and lymphoid tissue in the tumour stroma. FNA is a reliable diagnostic approach in the diagnosis of salivary gland lesions allowing a highly accurate categorization of benign tumour-like lesions, benign tumours and malignant tumours. In the proposed Milan reporting system of salivary gland lesions, WT is categorized in the IVA group of benign neoplasms. Accurate cytological diagnosis is straightforward when three characteristic components are present: oncocytes, either isolated or associated in clusters, lymphocytes and lymphoid cells and often an inflammatory/necrotic-like substance. Also, specific features of scintigraphy and radiological imaging contribute to the diagnosis of WT. WT is categorized according to Seifert G. et al in 4 types, depending on the proportions of the epithelial component and lymphoid stroma. Differential cytopathological and pathohistological diagnosis include other salivary gland lesions with lymphoid, oncocytic epithelial and cystic components. In some cases, such as the metaplastic WT variant, there are additional cytopathological and histological diagnostic difficulties. Moreover, bilateral, multicentric or multiple and infrequently seen extra-salivary localizations of WT are associated with further cytopathological diagnostic difficulties. Also, a rare possibility of malignant transformation of the epithelial or lymphoid component of WT as well as possible association with other primary tumours remains a challenge in accurate cytopathological and histological diagnosis of WT.

The effectiveness of the Milan system for risk stratification of salivary gland lesions: The 10-year cytohistopathological correlation results of salivary gland FNA cytology at a tertiary center

BACKGROUND

The Milan system reporting salivary gland cytopathology (MSRSGC) is a tiered classification scheme that is based on risk stratification. The aim of the current study was to assess the risk of malignancy (ROM) and risk of neoplasia (RON) in each of the diagnostic categories proposed by the MSRSGC.

METHODS

A retrospective analysis and categorization according to the MSRSGC was made of salivary gland fine needle aspirations (FNA) performed from January 2007 to December 2017. The FNA cytology results were correlated with subsequent histological follow-up.

RESULTS

A total of 578 FNAs were evaluated and histopathology was available for 198 cases (34.2%). The RON and ROM for individual diagnostic categories were: Non-diagnostic: 52.2% to 13%, non-neoplastic: 21.4% to 10.7%, atypia of undetermined significance: 74% to 22.2%, benign neoplasm: 100% to 1.1%, salivary gland neoplasm of uncertain malignant potential: 93.3% to 53.3%, suspicious for malignancy (SFM): 100% to 100%, and malignant: 100% to 100%. A diagnosis of 'SFM' or 'malignant' with FNA cytology carried a 100% risk for malignancy, while a diagnosis of "non-neoplastic," "benign neoplasm" reduced the probability of malignancy to 3.4%.

CONCLUSION

The MSRSGC is useful for the management of salivary gland lesions as it can successfully differentiate between benign and malignant cases. It will bring uniformity in salivary gland FNA cytology reporting across various institutions globally.

The Milan System, from Its Introduction to Its Current Adoption in the Diagnosis of Salivary Gland Cytology

Salivary gland masses are often encountered in the everyday practice of cytopathology. It is commonly known that the cytologic interpretation of these lesions can pose diagnostic problems due to overlapping cytomorphologic features. Fine needle aspiration (FNA) of salivary lesions shows good to excellent sensitivity and specificity in differentiating a neoplastic from a non-neoplastic process and in diagnosing common tumors such as pleomorphic adenoma. However, its value is limited in diagnosing specific neoplastic entities especially those with well-differentiated morphology. In light of this gap, an international group of pathologists has proposed a management-oriented, tiered classification for reporting salivary gland FNA specimens, “The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC)”. Similar to other classification systems, the MSRSGC scheme comprises six diagnostic categories, which were linked with a specific risk of malignancy (ROM) and management. In this review article, the author evaluated the published literature on FNA in diagnosing salivary gland lesions with the adoption of the Milan system since its introduction in the daily practice of salivary cytopathology.

The Milan System for Reporting Salivary Gland Cytopathology: An outcome of retrospective application to three years' cytology data of a tertiary care hospital

Objectives:

Fine-needle aspiration cytology (FNAC) of the salivary gland lesions has diverse and sometimes overlapping features that pose a diagnostic challenge for the cytopathologists. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has been introduced to bring uniformity in the reporting of salivary gland FNAC and improve the clinic-pathologic communication resulting in better patient management. The aim of the present study was to assess the application of the MSRSGC on FNAC specimens of salivary gland lesions at a tertiary care hospital.

Material and Methods:

All salivary gland aspiration cytology cases along with histopathology follow-up of salivary gland lesions, wherever available, over a period of 36 months were analyzed and re-categorized according to MSRSGC into six categories and the risk of malignancy (ROM) was computed.

Results:

Of the 123 patients, 23 (18.69%) were classified as non-diagnostic, 39 cases (31.7%) as non-neoplastic, one (0.81%) as atypia of undetermined significance (AUS), benign neoplasm in 49 (39.8%) cases, uncertain malignant potential in two cases (1.63%), suspicious of malignancy in two cases, and malignant in seven cases (5.69%). Out of 123 cases, histopathological correlation was available in 34 cases, for which the ROM was calculated. The ROM was 0% for non-neoplastic, 11.1% for benign neoplasm, and 100% each for salivary neoplasm of uncertain neoplastic potential, and 100% for malignant categories.

Conclusion:

In the present study, the distribution of cases according to MSRSGC was comparable with the previous studies. The proportion of cases classified as AUS was within the goal set by MSRSGC at less than 10%. A risk-based stratification of salivary gland lesions in the form of MSRSGC is essential in the present era to guide and alert the clinician about the subsequent management plan and convey the ROM.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Is there a Role for Frozen Section Evaluation of Parotid Masses After Preoperative Cytology or Biopsy Diagnosis?

Fine-needle aspiration (FNA) biopsy reliably diagnoses parotid gland lesions preoperatively, whereas intraoperative frozen section (FS) has the additional benefit of assessing surgical margins and refining diagnoses; however, the role of FS in the setting of prior FNA diagnosis is not well established. Our aim was to determine whether FS should still be performed after a prior FNA/ CNB diagnosis. Parotid gland resections from January 2009 to January 2020 were identified; however, only patients who had both FNA and FS constituted our study population. For the purpose of statistical analysis, FNA diagnoses were classified into non-diagnostic (ND), non-neoplastic (NN), benign neoplasm (BN), indeterminate, and malignant. FS diagnoses were classified into benign, indeterminate, or malignant. Resections were dichotomized into benign and malignant and regarded as the gold standard to subsequently calculate diagnostic accuracy of FNA and FS. A total of 167 parotid gland resections were identified, but only 76 patients (45.5%) had both FNA and FS. In 35 cases deemed as benign preoperatively, three (8.6%) were reclassified as malignant on FS. Out of 18 lesions reported as malignant on FNA, four (22.2%) were interpreted as benign on FS, with three of these benign lesions confirmed on permanent slides. In addition, in patients with both FNA and FS, compared to FNA, FS was able to provide a definitive diagnosis in all five ND cases and in 61.1% (11/18) of indeterminate tumors. Intraoperative assessment provided a relative increase of 33.3% in specificity and 38.5% in positive predictive value when compared to preoperative FNA. The addition of FS to FNA was helpful to further refine the diagnoses of parotid gland lesions, which may provide better guidance for surgical intervention.

Putting morphology to the test: An established classification scheme reliably stratifies salivary gland cytology by risk of malignancy with substantial interobserver agreement

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology describes several salivary gland fine-needle aspiration cytology (SGFNAC) morphologies developed by Griffith et al. Basaloid neoplasms are pleomorphic (PB) or monomorphic with fibrillary (MBFib), hyaline (MBHy), or other (MBOther) matrix. Oncocytoid neoplasms can be pleomorphic (PO), demonstrate granular and/or vacuolated cytoplasm (OGV), or be monomorphic with mucinous (MOMuc), cystic (MOCyst), or other (MOOther) background. In the current study, the authors explore interobserver agreement (IOA) and risk of malignancy (ROM) for these subcategories.

METHODS

The study included 169 SGFNAC cases with surgical follow-up. Four reviewers categorized these cases using the criteria of Griffith et al. with consensus determined by majority. For all morphologic categories, IOA (using the Fleiss kappa) and ROM were calculated.

RESULTS

ROMs for basaloid categories were: PB: 100% (1 of 1 case); MBHy: 71.4% (5 of 7 cases); MBFib: 50.0% (3 of 6 cases); and MBOther: 47.4% (9 of 19 cases). ROMs for oncocytoid neoplasms were: OGV: 100% (10 of 10 cases); MOMuc: 92.3% (12 of 13 cases); PO: 88.9% (8 of 9 cases); MOOther: 33.3% (5 of 15 cases); and MOCyst: 0 (0 of 1 case). The system demonstrated substantial agreement overall (κ = 0.69). For basaloid neoplasms, the IOA results were: MBHy: κ = 0.59; MBFib: κ = 0.41; MBOther: κ = 0.41; and PB: κ = 0.11. For oncocytoid neoplasms, the IOA results were: MOMuc: κ = 0.88; OGV: κ = 0.67; PO: κ = 0.63; MOOther: κ = 0.57; and MOCyst: κ = 0.18.

CONCLUSIONS

The SGFNAC scheme proposed by Griffith et al. and incorporated into the Milan System for Reporting Salivary Gland Cytopathology demonstrated substantial agreement overall, with particularly high agreement for the MOMuc, OGV, PO, and MBHy categories. The PB and MOCyst categories demonstrated slight agreement and may be improved by revised criteria. The PB, PO, MOMuc, and OGV categories demonstrated high ROM, and the latter 2 categories might best be classified as suspicious for malignancy.

Application of the Milan System for Reporting Salivary Gland Cytopathology: Experience of an academic institution in a tertiary academic medical center

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) represents a standardized reporting system for salivary gland lesions. The recent literature has demonstrated a wide range of data regarding range of malignancy (ROM) and interobserver variability. The objective of the current study was to evaluate the reproducibility and interobserver agreement of MSRSGC, and establish the ROM in a unique patient population residing within a designated Health Professional Shortage Area.

METHODS

A total of 380 salivary gland fine-needle aspiration cases were obtained over a 3-year period. Corresponding cytology reports and slides were reviewed in a blinded fashion by a panel of cytopathologists and recategorized using MSRSGC. ROM was calculated by cytohistologic correlation in 176 cases. Agreement between review of reports and slides and interobserver reliability were determined using kappa statistics.

RESULTS

The ROMs per MSRSGC category based on review of reports and slides were as follows: 4% and 0%, respectively, for nonneoplastic; 22% and 0%, respectively, for nondiagnostic; 42.9% and 48%, respectively, for atypia of undetermined significance; 1.6% and 1.9%, respectively, for benign-neoplastic; 17.9% and 15.6%, respectively, for salivary gland neoplasm of uncertain malignant potential; 81.8% and 71.4%, respectively, for suspicious for malignancy; and 100% and 90.5%, respectively, for malignant. There was a 59.2% overall agreement between review of reports and slides with regard to recategorizing salivary gland lesions (kappa, 0.51). The interobserver reliability demonstrated a 64.6% agreement (weighted kappa, 0.59).

CONCLUSIONS

The ROMs at the study institution appeared comparable to those in the published literature. There was moderate overall agreement among cytopathologists and low interobserver agreement with regard to the indeterminate categories. Image-guided fine-needle aspiration specimens; rapid onsite adequacy; and integration of clinical, imaging, and ancillary studies can improve diagnostic accuracy among indeterminate lesions.

Retrospective implementation of the Milan system for reporting salivary gland cytopathology; a review of 5 years in a specialized cancer center

BACKGROUND

The Milan system for reporting salivary gland cytopathology (MSRSGC) aims to standardize terminology, facilitate communication, and optimize management by providing risk of malignancy (ROM) for each category. Our retrospective cohort aims to study the reproducibility of reporting using the MSRSGC and to calculate the ROM for each category.

METHODS

Cases of fine needle aspiration (FNA) of salivary glands and related cervical lymph nodes were retrieved from our files between 2015 to 2019. From a total of 63 cytology cases, 57 cases had available material for cytological reexamination of which 45 cases had follow up data. All cases were reviewed independently by two pathologists and reclassified based on the MSRSGC. The reclassification of cases for both pathologists was compared and the ROM for each diagnostic category was calculated.

RESULTS

The 57 cases were studied. Both pathologists had initial concordance in classification of 52 of 57 cases. The remainder five cases were concurred upon after combined review. The cases were classified as: Non Diagnostic (ND); (n = 8), Non Neoplastic (NN); (n = 7), Atypia of Undetermined Significance (AUS); (n = 8), Neoplasm Benign (NB) (n = 10), Salivary Gland Neoplasm of Uncertain Malignant Potential (SUMP) (n = 5), Suspicious for Malignancy (SM) (n = 1) and Malignant (M) (n = 18). The ROM was: ND: (33.3%); NN: (0%); AUS (33.3%); NB (0%); SUMP (25%); SM (100%) and M (100%).

CONCLUSION

Applying the MSRSGC is reproducible which facilitates standardization of reports and stratifying cases preoperatively. In general, the ROM for our cases was close to that reported in the literature.

Next-generation sequencing assay in salivary gland cytology: A pilot study

BACKGROUND

Preoperative diagnosis of salivary gland tumors (SGTs) by fine-needle aspiration (FNA) cytology is challenging. Next-generation sequencing (NGS)-based assays for somatic mutations have a great advantage in that a large number of genes can be analyzed simultaneously. Although NGS may have an enormous diagnostic potential in cytology, to our knowledge, the significance of NGS in SGT cytology remains to be clarified.

METHODS

In this pilot study, we retrospectively examined 32 frozen SGT samples obtained at surgery (14 malignant and 18 benign). After the stored frozen tumor tissues were thawed, aspirate samples were obtained using 22-gauge needles and subjected to smear tumor samples and to DNA extraction for an NGS assay employing the Illumina AmpliSeq Cancer Hotspot Panel v2. The results were correlated to preoperative cytological diagnosis.

RESULTS

The preoperative diagnoses obtained by FNA cytology included 23 negative lesions (no malignancy in 6 and benign tumor in 17) and nine positive lesions (suspicious for malignancy in 4 and malignancy in five), providing a sensitivity and a specificity of 9/14 (64%) and 18/18 (100%), respectively. The NGS assay detected somatic mutations in 10/14 malignant and 1/18 benign SGT cases, providing a sensitivity and a specificity of 71% and 94%, respectively.

CONCLUSION

The NGS assay may be helpful for detecting the malignant potential in SGT cases and can be used as an ancillary test for SGT cytology.

Cytomorphology and diagnostic pitfalls of sebaceous and nonsebaceous salivary gland lymphadenoma: A multi-institutional study

BACKGROUND

Salivary gland lymphadenoma (LAD) is a rare benign neoplasm comprising sebaceous (SLAD) and nonsebaceous (NSLAD) types. Despite established histologic criteria, limited data on cytomorphology, tumor heterogeneity, and overlap with other entities make the diagnosis of LAD by fine needle aspiration (FNA) challenging. We describe a multi-institutional cohort of 14 LADs with cytology, clinical, radiologic, and histopathologic data.

METHODS

Our cohort included nine SLAD and five NSLAD with corresponding histopathology. Mean patient age and M:F ratio were 60.4 years (range 45-86 years) and 1:2 for SLADs and 57.4 years (range 42-80 years) and 1:1.5 for NSLADs, respectively. One NSLAD patient had a germline predisposition for Cowden syndrome. Glass slides and whole slide images of air-dried Diff-Quik (DQ), alcohol-stained Papanicolaou smears (Pap) and cellblocks were reviewed for key cytomorphologic findings.

RESULTS

FNAs from SLAD and NSLADs demonstrated vacuolated and basaloid epithelial clusters within a lymphoid background. Vacuolated cells from SLAD showed sebaceous cells with microvesicular cytoplasm indenting a central nucleus. Vacuolated cells from NSLAD were columnar with eccentric nuclei, corresponding to abluminal glandular cells. SLADs were classified using the Milan System for Reporting Salivary Gland Cytopathology as nondiagnostic (11.1%), nonneoplastic (44.4%), atypia of uncertain significance (AUS) (22.2%), and salivary gland neoplasm of uncertain malignant potential (SUMP) (22.2%). NSLADs were classified as AUS (40%), SUMP (40%) and Benign Neoplasm (20%).

CONCLUSION

Although rare, knowing the cytologic features of salivary LAD is important to avoid diagnostic pitfalls. Vacuolated cells can be prominent in both SLAD and NSLAD aspirates. Diagnostic issues arise from insufficient sampling of all tumor components leading to marked variation in diagnostic classification of LAD.

Application of Milan system for reporting of salivary gland pathology and risk stratification: An institutional experience

Background:

Fine-needle aspiration cytology (FNAC) is a sensitive technique for diagnosing salivary gland pathologies. Milan system of reporting salivary gland cytopathology (MSRSGC) is an evidence-based system of reporting which has been introduced to improve reporting and communication between cytopathologist and clinician by introducing standardized categories with specified treatment protocols.

Aims and Objectives:

The aim of the present study is to find the diagnostic accuracy and risk of malignancy (ROM) in various categories when MSRSGC is applied.

Materials and Methods:

A single-institute-based 3-year retrospective study was done. All salivary gland lesions were reclassified according to MSRSGC. ROM, diagnostic specificity, sensitivity and accuracy of FNAC of salivary gland lesions were calculated.

Results:

A total of 133 cases were included in the study. Overall, the most common diagnosis was found to be pleomorphic adenoma comprising 61 (42.8%) of all cases. Adenoid cystic carcinoma was the most commonly diagnosed malignancy comprising of 6 (4.5%) of all lesions. Cases were further divided into Milan categories, namely nondiagnostic, nonneoplastic, atypia of undetermined significance, benign neoplasm, neoplasm of undetermined malignant potential, suspicious of malignancy and malignancy comprising 5 (3.7%), 29 (21.8%), 77 (57.8%), 4 (3%), 3 (2.2%), 1 (0.7%) and 14 (10.5%) cases, respectively, with ROM of 0, 14.28%, 33.33%, 5.71%, 66.66%, 100% and 80%, respectively. Sensitivity, specificity and diagnostic accuracy to separate benign from malignant lesions were 80%, 89.80% and 87.50%, respectively.

Conclusion:

FNAC of the salivary gland lesions is a safe and reliable diagnostic procedure. The Milan system of reporting is a risk stratification system which can improve the overall effectiveness of reporting and care of patients.

Impact of the Milan System for Reporting Salivary Gland Cytology on risk assessment when used in routine practice in a real-time setting

INTRODUCTION

Several retrospective studies across the world have validated the role of the Milan System for Reporting Salivary Gland Cytology (MSRSGC) in improving communication between pathologists and clinicians. In this study, we evaluated the applications of MSRSGC in a real-time setting for 2 years.

MATERIALS AND METHODS

All salivary gland lesions that underwent fine-needle aspiration (FNA) from January 2018 to December 2020 were categorized according to MSRSGC guidelines. The risk of malignancy (ROM) was calculated for each category and compared with the ROM proposed by MSRSGC and recent retrospective studies.

RESULTS

A total of 160 FNA of salivary gland lesions were categorized as: nondiagnostic (ND) 30 (18%), non-neoplastic (NN) 7 (10.6%), atypia of undetermined significance (AUS) 5 (3.1%), benign neoplasm (BN) 59 (36.8%), salivary gland of uncertain malignant potential (SUMP) 21 (13%), suspicious for malignancy (SM) 3 (1.84%), and malignant (M) 25 (15.6%). Histopathologic follow-up was available for 94 (57.5%) cases. The ROM for each category was ND 54%, NN 0%, AUS 66%, BN 0%, SUMP 37.56%, SM 100%, and M 100%.

CONCLUSION

With strict adherence to the diagnostic criteria and MSRSGC guidelines, a ROM of 100% in SM and M categories and a ROM of 0% in NN can be achieved in a real-time setting. The high ROM in the ND category in our study highlights the value of repeat FNA/biopsy for this category. High ROM for AUS indicates the tendency to classify high-grade tumors as AUS, calling for refinement in its criteria.

A retrospective cytohistological correlation of fine-needle aspiration cytology with classification by the Milan System for Reporting Salivary Gland Cytopathology

Background

Before publication of the new classification system named the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) in 2018, there was no standard classification for salivary gland lesions obtained by fine-needle aspiration (FNA). We therefore aimed to evaluate the diagnostic utility of this system by retrospectively reviewing FNA samples using the MSRSGC and to determine their risk of developing into neoplasms and becoming malignant.

Methods

Retrospective slide review and classification of salivary gland FNAs obtained over a 6-year period (2013–2018) at a single center were performed by two pathologists. The risks of neoplasm and malignancy for each category also were calculated.

Results

This study surveyed 374 FNAs (371 patients) performed over a six-year period and selected 148 cases that included documented surgical follow-up (39.6%). Among the surgically treated cases, the distributions of FNA categories were as follows: non-diagnostic (ND; 16.9%), non-neoplastic (NN; 2.7%), atypia of undetermined significance (AUS; 3.4%), benign (BN; 54.7%), salivary gland neoplasm of uncertain malignant potential (SUMP; 10.1%), suspicious for malignancy (SM; 6.8%), and malignant (M; 5.4%). The risk of malignancy (ROM) was 24.0% for ND, 0% for NN, 40.0% for AUS, 2.5% for BN, 46.7% for SUMP, 100% for SM, and 87.5% for M. The overall diagnostic accuracy was 95.9% (142/148 cases).

Conclusions

The newly proposed MSRSGC appears to be a reliable system for classification of salivary gland lesions according to the associated ROM.

Current classification systems and standardized terminology in cytopathology

The history of classification systems and the search for a unified nomenclature in cytopathology spans several decades and expresses the preoccupation of all those involved to make cytopathology a reliable diagnostic tool and a trusted screening method. Early classification schemes, applicable to exfoliative and aspiration cytology, attempted to set some basic standards for how non-gynecological cytopathology findings should be reported. While useful in establishing some basic guidelines, these were not specific to the various fields of non-gynecologic cytopathology, often burdened with specific problems. Cytopathology has evolved tremendously in the last couple of decades, undoubtedly boosted by the emergence of various classification schemes that, more than ever, are based on evidence gathered by professionals across the globe. The benefit of classification systems and standardized nomenclature in cytopathology is to provide useful, clear, and clinically relevant information for clinicians and ultimately to provide the best patient care. Standardized reporting systems make cytopathology reports more meaningful and robust. It now became standard that these include by default elements, such as adequacy criteria, diagnostic groups, risk of malignancy (ROM), and recommendations for patient management. In this brief review, we attempted to summarize how these classification schemes emerged and how they are reshaping the landscape of diagnostic cytopathology.

A multicenter validation of the revised version of the Milan system for reporting salivary gland cytology (MSRSGC)

INTRODUCTION

Fine-needle aspiration cytology (FNAC) is a basic step in the diagnosis of salivary gland tumors that have a wide variety of histological types. The recent Milan system for reporting salivary gland cytopathology (MSRSGC) can correlate the risk of malignancy with precise cytological features. A revised version was recently proposed to improve the surgical relevance and facilitate uniform management.

MATERIAL AND METHODS

A multicenter study retrospectively used the original and revised MSRSGC criteria to classify a series of patients who received surgery after FNAC.

RESULTS

We enrolled 503 patients from three tertiary centers. The risk of malignancy for the MSRSGC resulted 19.5% in cat. I, 14.3% in cat. II, 17.6% in cat. III, 3.6% in cat. IVa, 24.6% in cat. IVb, 66.7% in cat. V, and 96.8% in cat. VI. The results from the revised MSRSGC were consistent with the original values.

CONCLUSION

The MSRSGC is a promising classification system. In our opinion, the revised version of the MSRSGC supplements FNAC with some crucial clinical information and can better identify the appropriate treatment in each category.

Interobserver variability between cytopathologists and cytotechnologists upon application and characterization of the indeterminate category in the Milan System for Reporting Salivary Gland Cytopathology

BACKGROUND

The indeterminate categories in the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) are diagnostically challenging because of inherent heterogeneity and complexity, with wide interobserver variability (IOV). Herein, the authors explore the concordance rate (CR) between cytopathologists (CPs) and cytotechnologists (CTs) in interpreting indeterminate salivary gland lesions using the MSRSGC.

METHODS

Between 2011 and 2016, 86 indeterminate fine-needle aspirations had slides available for review, of which 48 had follow-up. Four CPs and 2 CTs performed an independent, blinded review of these slides and categorized them according to the MSRSGC. The CRs between CTs and CPs with the final sign-out cytopathologist (FCP) were assessed, and interobserver agreement was categorized into uniform, majority, divided, minimal, or no agreement.

RESULTS

The overall CR with the FCP ranged from 48.8% to 60.5% for CPs and from 22.1% to 36% for CTs. IOV κ scores for the entire group were 0.314 and, with the FCP as the reference, ranged from 0.403 to 0.539 for CPs and from 0.091 to 0.254 for CTs. Uniform, majority, divided, minimal, and no agreement was noted in 12.8%, 31.4%, 38.4%, 10.5%, and 6.9%, respectively, of all cases and in 16.7%, 35.4%, 31.3%, 8.3%, and 6.3%, respectively, of the cases with follow-up. Diagnostic challenges included distinguishing lymphoma from a reactive process and distinguishing mucin from mucin-like material.

CONCLUSIONS

CPs had modestly higher CRs compared with CTs; and, although the variable CRs highlight indeterminate IOV, the MSRSGC enables reproducibility. Characterizing larger cohorts in the indeterminate categories will further improve MSRSGC criteria. Moreover, education on the MSRSGC should include CTs and CPs to improve overall diagnostic accuracy.

The Milan system for reporting salivary gland cytopathology: Single center experience with cell blocks

BACKGROUND

Salivary gland fine needle aspiration (FNA) has a well-established role in the evaluation of salivary gland lesions. The Milan system for reporting salivary gland cytopathology (MSRSGC) was developed in 2018 to accomplish a standardized reporting across institutions. This classification is predominantly based on the use of direct smears. This single center study aims to evaluate and further validate the MSRSGC based on the sole use of cell blocks and carry out a risk assessment based on follow up histopathology.

METHODS

A total of 359 FNA specimens from 343 patients processed as cell blocks between 2012 and 2018 were retrieved, with histologic follow-up available in 235 cases. The cytological diagnosis were reclassified according to the MSRSGC categories: non-diagnostic, non-neoplastic, atypia of undetermined significance (AUS), benign neoplasm, salivary gland neoplasm of uncertain malignant potential (SUMP), suspicious for malignancy (SFM), and malignant. The use of ancillary immunohistochemistry or molecular testing was recorded. The risk of malignancy (ROM) was calculated for each diagnostic category.

RESULTS

Overall accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 92.9%, 75.9%, 97.9%, 91.7%, and 95%, respectively. The ROM for the non-diagnostic, non-neoplastic, AUS benign neoplasms, SUMP, SFM and malignant categories were 13.8%, 14.2%, 30%, 6.3%, 20.8%, 60%, and 100%, respectively.

CONCLUSION

This large single center retrospective series further validates the MSRSGC. The proposed diagnostic classification is reproducible with use of cell blocks. Discrepancies in number of cases per category and ROM are based on cross-institution variabilities, pre-FNA diagnostics (imaging) and ancillary tests.

Retrospective application of the Milan System for reporting salivary gland cytopathology: A Cancer Center experience

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was recently proposed. Herein, we retrospectively applied this nomenclature system to salivary gland lesions sampled by ultrasound-guided fine-needle aspiration (FNA).

METHODS

All cases of salivary gland FNA with available surgical follow-up, in the period from 2014 to 2017 at our institution were reviewed and reclassified according to one of the six categories of the MSRSGC, blind to the surgical outcome. Overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated, as well as risks of neoplasm (RON) and risk of malignancy (ROM) for each of the proposed categories.

RESULTS

There were 104 salivary gland lesions, with a female predominance (57.7%), most cases from the parotid gland (89.4%). Mean age was 53.2 years. Distribution of the specimens according to the Milan System was as follows: 19.2% nondiagnostic (ND), 8.7% non-neoplastic (NN), 9.6% atypia of undetermined significance (AUS), 40.4% benign neoplasm (BN), 14.4% salivary gland neoplasm of uncertain malignant potential (SUMP), 1.9% suspicious for malignancy (SFM), and 5.8% malignant. Sensitivity, specificity, PPV, and NPV using MSRSGC were calculated as 75%, 98.4%, 88.9%, and 95.3%, respectively. RON/ROM for each category were 60%/15% for ND, 44.4%/0% for NN, 90%/40% for AUS, 100%/9.5% for BN, 100%/13.3% for SUMP, 50%/50% for SFM and 100%/100% for malignant.

CONCLUSION

The use of the Milan System proved to be a useful method to predict the risk of neoplasm and malignancy in the sample studied, with high sensitivity and specificity.

Fine-needle aspiration cytology in the diagnosis of salivary gland lesions. The role of the Milan system for reporting cytopathology

BACKGROUND

Fine needle aspiration cytology (FNAC) is an established technique in the management of salivary gland lesions. The Milan System for reporting salivary gland cytopathology (MSRSGC) intents to standardize diagnostic categories. Current studies are trying to evaluate the diagnostic approach of this system.

METHODS

FNAC of salivary gland lesions were retrieved over an 11-year period. 185 FNAC specimens from 182 patients were reviewed blindly and classified according to the criteria established by the MSRSGC. 136 (74.7%) patients had follow-up of their processes.

RESULTS

The total number of diagnostic categories and risk of malignancy (ROM) in 185 specimens were the following: non-diagnostic 39 (21.1%; ROM 12%), non-neoplastic 35 (18.9%; ROM 0%), atypia of undetermined significance (AUS) 17 (9.2%; ROM 46.1%), benign neoplasm 75 (40.5%; ROM 4.9%), salivary gland neoplasm of uncertain malignant potential 4 (2.2%; ROM 100%), suspicious for malignancy 7 (3.8%; ROM 100%), malignant 8 (4.3%; ROM 100%). No false positives were observed in groups IVb, V, and VI in this series. The overall sensitivity, specificity, negative predictive value, positive predictive value and diagnostic accuracy were 88%, 91.8%, 96.3%, 76.7%, and 91% respectively.

CONCLUSION

The ROM reported in our study was in keeping with ROM published by the MSRSGC. This system provides standardized information for risk stratification. The category AUS encompassed cases causing uncertainty representing a challenge in management. Defining criteria for AUS category need to be refined. The system facilitates communication between pathologists and clinicians favoring improvement in patient care.

Cytologic grading of primary malignant salivary gland tumors: A blinded review by an international panel

BACKGROUND

Fine needle aspiration (FNA) is commonly used for the preoperative evaluation of salivary gland tumors. Tumor grade is a key factor influencing clinical management of salivary gland carcinomas (SGCs). To assess the ability to grade nonbasaloid SGCs in FNA specimens, an international panel of cytopathologists convened to review and score SGC cases.

METHODS

The study cohort included 61 cases of primary SGC from the pathology archives of 3 tertiary medical centers. Cases from 2005 to 2016 were selected, scanned, and digitized. Nineteen cytopathologists blinded to the histologic diagnosis reviewed the digitized cytology slides and graded them as low, high, or indeterminate. The panelists' results were then compared to the tumor grades based on histopathologic examination of the corresponding resection specimens.

RESULTS

All but 2 of the 19 (89.5%) expert panelists review more than 20 salivary gland FNAs per year; 16 (84.2%) of the panelists work at academic medical centers, and 13 (68.4%) have more than 10 years' experience. Participants had an overall accuracy of 89.4% in the grading of SGC cases, with 90.2% and 88.3% for low- and high-grade SGC, respectively. Acinic cell carcinoma and mucoepidermoid carcinoma had the highest degree of accuracy, while epithelial-myoepithelial carcinoma and salivary duct carcinoma had the lowest degree of accuracy. As expected, the intermediate-grade SGC cases showed the greatest variability (high-grade, 42.1%; low-grade, 37.5%, indeterminate, 20.4%).

CONCLUSION

This study confirms the high accuracy of cytomorphologic grading of primary SGC by FNA as low- or high-grade. However, caution should be exercised when a grade cannot be confidently assigned.

Milan System for Reporting Salivary Gland Cytopathology- An Experience from Western Indian Population

Introduction:

Fine-needle aspiration cytology (FNAC) can be challenging to provide a precise diagnosis in salivary gland cytopathology due to diversity of lesions and cytomorphological convergence between the tumors and within the same tumor of salivary gland. The recently proposed Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) provides a risk stratification-based classification system with an intrinsic risk of malignancy (ROM) for each diagnostic category, which aims to furnish useful information to the clinicians. This study was undertaken to evaluate the diagnostic utility and validity of MSRSGC.

Methods and Material:

In this retrospective study, FNAC done for all salivary gland lesions over a period of two years were retrieved. All cases were categorized according to MSRSGC and correlated with histopathological follow-up, wherever available. ROM was calculated for each category.

Results:

The cases belong to following categories: non-diagnostic (1.27%), non-neoplastic (30.38%), atypia of undetermined significance (5.06%), benign neoplasm (46.84%), salivary gland neoplasm of uncertain malignant potential (1.27%), suspicious for malignancy (1.27%), and malignant (13.92%). Out of 79 cases, 50.63% had follow-up. The ROM were 0% for category II and IVa, 50% for category III, and 100% for category IVb, V, and VI. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were recorded as 77.78%, 100%, 100%, 91.3%, and 93.33%, respectively.

Conclusions:

Application of MSRSGC has immense value for standardization of reporting of salivary gland FNAC. Our data corresponds to the studies done worldwide and recommends the use of MSRSGC for future diagnostic purposes.

Evaluation of Accuracy of Milan System for Reporting Salivary Gland Cytology: Review of Morphology and Diagnostic Challenges in Each Category

Background:

Fine-needle aspiration cytology (FNAC) in salivary gland lesions is challenging for the cytopathologists due to diverse morphological pattern and overlapping morphologic features which are responsible for the pitfalls. The present study was conducted to evaluate the efficacy of the Milan system in the diagnosis of salivary gland lesions and to discuss and review the morphology and diagnostic challenges in individual Milan categories.

Materials and Methods:

The study was a retrospective diagnostic analytical study in the department of pathology at a tertiary care hospital attached to medical college over a duration of 2 years. All the salivary gland FNAC cases were reviewed and divided into six categories as per the proposed Milan system for reporting salivary gland cytopathology. Histopathology correlation was performed wherever possible.

Results:

A total of 131 cases formed the study group. The number of cases in each category were: nondiagnostic 4.5%, nonneoplastic 51.9%, atypical lesions 0.76%, neoplastic category benign neoplasm 21.37%, salivary lesion of uncertain malignant potential 1.52%, suspicious category 2.29%, and malignant category 17.5%. The risk of malignancy for each categories were 6.25% (nonneoplastic), 100% (atypical), 3.3% (neoplastic), 0% (benign), 25% (salivary neoplasm of uncertain neoplastic potential), 100% (suspicious for malignancy), and 100% (malignant) categories. Sensitivity, specificity, positive predictive value, and negative predictive value of FNAC with application of Milan system was 89.4%, 100%, 100%, and 95.74%, respectively.

Conclusion:

The high efficacy of FNAC obtained in the present study, when Milan system was applied, confirms the usefulness of this scheme in reporting salivary gland lesions.

Diagnostic performance and inter-operator variability of apparent diffusion coefficient analysis for differentiating pleomorphic adenoma and carcinoma ex pleomorphic adenoma: comparing one-point measurement and whole-tumor measurement including radiomics approach

BACKGROUND AND PURPOSE

The purpose of this study was to compare the diagnostic performance between apparent diffusion coefficient (ADC) analysis of one-point measurement and whole-tumor measurement, including radiomics for differentiating pleomorphic adenoma (PA) from carcinoma ex pleomorphic adenoma (CXPA), and to evaluate the impact of inter-operator segmentation variability.

MATERIALS AND METHODS

One hundred and fifteen patients with PA and 22 with CXPA were included. Four radiologists with different experience independently placed one-point and whole-tumor ROIs and a radiomics-predictive model was constructed from the extracted imaging features. We calculated the area under the receiver-operator characteristic curve (AUC) for the diagnostic performance of imaging features and the radiomics-predictive model.

RESULTS

AUCs of the imaging features from whole-tumor varied between readers (0.50-0.89). The most experienced radiologist (Reader 1) produced significantly high AUCs than less experienced radiologists (Reader 3 and 4; P = 0.01 and 0.009). AUCs were higher for the radiomics-predictive model (0.82-0.87) than for one-point (0.66-0.79) in all readers.

CONCLUSION

Some imaging features of whole-tumor and radiomics-predictive model had higher diagnostic performance than one-point. The diagnostic performance of imaging features from whole-tumor alone varied depending on operator experience. Operator experience appears less likely to affect diagnostic performance in the radiomics-predictive model.

The Milan System at Memorial Sloan Kettering: Utility of the categorization system for in-house salivary gland fine-needle aspiration cytology at a comprehensive cancer center

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) provides a standardized reporting system for salivary gland fine-needle aspiration (SGFNA). We review the clinical utility of the MSRSGC at a tertiary care cancer center by assessing the rates of malignancy (ROM) among different categories.

METHODS

A retrospective search was performed to retrieve all SGFNA cases performed at our institution between 1/1/07 and 12/31/18. The initial primary diagnoses were recorded and cases were then assigned to appropriate MSRSGC categories. ROM was then calculated for all categories.

RESULTS

A total of 976 cases were identified, and 373 with follow-up. The ROM was 19.7% (192/976) for all-comers and 51.3% (192/374) among cases with follow-up. Using MSRSGC, SGFNA showed a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 65.6%, 87.4%, 100%, and 72.6%, respectively. ROM for MSRSGC categories I, II, III, IVa, IVb, V, and VI were 20.7%, 30.0%, 45.8%, 3.3%, 50.7%, 100%, and 100%, respectively. Utilizing MSRSGC resulted in a nondiagnostic rate of 14.4%. The nondiagnostic rate was lower when the procedure was performed by pathologists vs nonpathologists (12.9% vs 15.8%) but was comparable when rapid on site evaluation (ROSE) was performed (12.9% vs 11.6%).

CONCLUSION

In our patient population, MSRSGC resulted in a perfect PPV and moderate NPV. Utilizing MSRSGC results in a higher nondiagnostic rate due to the inclusion of cases with benign elements or cyst contents only in this category. Performing ROSE is more important in attaining an adequate sample than the specialty of the person performing SGFNA.

Application of the Milan System for Reporting Salivary Gland Cytopathology: A retrospective study in a tertiary institute

BACKGROUND

Fine needle aspiration (FNA) cytology has been widely used in the preoperative evaluation of salivary gland lesions. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is a tiered risk-stratification scheme designed to standardize reporting and facilitate decision making. We aimed to clarify the validity and diagnostic utility of the MSRSGC-based classification of salivary gland lesions.

METHODS

A total of 1020 salivary gland FNA specimens were retrieved between 2008 and 2017, with histologic follow-up data available for 349 specimens. Within the present retrospective study, each specimen with follow-up data was reclassified according to the MSRSGC diagnostic categories: nondiagnostic, nonneoplastic, atypia of undetermined significance (AUS), benign neoplasm, salivary gland neoplasm of uncertain malignant potential (SUMP), suspicious for malignancy (SM), and malignant. The risk of malignancy (ROM) was calculated based on the histologic follow-up data.

RESULTS

The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the MSRSGC-based classification of the malignant potential of salivary gland lesions were 80.1%, 70.4%, 99.2%, 90.5%, and 96.7%, respectively. The ROM calculated for specimens assigned to the nondiagnostic, nonneoplastic, AUS, benign neoplasm, SUMP, SM, and malignant categories were 8.6%, 15.4%, 36.8%, 2.6%, 32.3%, 71.4%, and 100%, respectively.

CONCLUSION

The present results confirm the validity and diagnostic utility of MSRSGC, supporting its use in clinical practice to help devise adequate management strategies for salivary gland lesions.