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

A systematic review on the role of biomarkers in liquid biopsies and saliva samples in the monitoring of salivary gland cancer

BACKGROUND

Salivary gland cancer is a rare disease, and approximately 20% of tumors in the salivary glands are malignant. Reliable biomarkers may have a role in monitoring salivary gland cancer.

AIM

To review the current literature on the role of biomarkers in liquid biopsies and saliva samples in the monitoring of salivary gland cancer.

MATERIALS AND METHOD

This study systematically reviewed the literature on studies detecting salivary gland cancer by biomarkers in liquid biopsies and saliva samples by systematically searching PubMed and Embase between 1 January 2013 and 7 March 2023.

RESULTS

Five studies covering 64 malignant cases of salivary gland cancer were included, which considered inflammatory biomarkers or markers of genetic material in either blood or saliva. In saliva, there were demonstrated elevations of CA-19-9 in malignant cases, and elevations of miRNA in malignant and benign cases. In blood, there were demonstrated elevations of IL-33 in malignant and benign cases, elevations of ctDNA in malignant cases, and elevations of CTC in malignant cases.

CONCLUSION AND SIGNIFICANCE

The studies indicate that there is potential in the detection method. The studies detecting genetic material by liquid biopsies showed the most promising results. At present, there is still progression to be made before the method can be implemented for diagnostic use.

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.

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.