Utility of the Milan system for reporting salivary gland cytopathology during rapid on-site evaluation (ROSE) of salivary gland aspirates

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

OBJECTIVES

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

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

INTRODUCTION

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Does Milan affect management? A retrospective analysis of resection rate and time to surgery among Milan categories

INTRODUCTION

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is an established system with reproducible risk of malignancies (ROM) for salivary gland fine needle aspiration (SGFNA). No studies have reviewed the relationship between Milan categories and the resection rate (RR) and time to resection (TTR).

METHODS

We searched our database (January 1, 2011 to January 4, 2021) for non-lymphoma SGFNAs and assigned appropriate MSRSGC categories. RR and TTR were calculated and compared for each category. A literature search was performed; RRs and TTRs were compared.

RESULTS

Seven hundred and eighty SGFNAs were identified, 333 with follow-up. RR was highest in suspicious for malignancy (SUS, V; 70.6%, n = 12/17), followed by the salivary gland neoplasm of uncertain malignant potential (SUMP, IVb; 69.6%, n = 80/115) and malignant (M, VI; 55.6%, n = 75/135). Among M, primary tumors had a higher RR (65.1%, n = 41/63) than metastases (47.2%, n = 34/72, p = .36). In literature review, SUS had the highest RR (69.3%, n = 233/336) followed by M (61.6%, n = 821/1332) and SUMP (60.2%, n = 632/1050). TTR was shorter in SUS (mean = 32.3 days, median = 25 days). Within the benign neoplasms (BN, IVa), Pleomorphic adenomas (PAs) had a higher RR than Warthin tumors (WTs) (66.3% vs. 37.2%, p < .00001), and a shorter TTR (median = 63 days vs. 90 days).

CONCLUSIONS

Tumors classified as SUS had higher RR and at shorter intervals than those classified as SUMP. PAs have higher RRs and more expedient surgery than WTs. Cases classified as M are less likely to undergo follow-up than SUS, perhaps due to a lower RR for metastases.

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.

Validation of a Cytological Classification System for the Rapid On-Site Evaluation (Rose) of Pulmonary and Mediastinal Needle Aspirates

Rapid on-site evaluation (ROSE) is a procedure that allows immediate assessment of adequacy of cytological specimens obtained by fine needle aspiration (FNA). The application of ROSE diagnostic categories has been applied in various organs, but not in thoracic pathology. We aimed to retrospectively assess the concordance with the final diagnosis of a categorization from C1 (inadequate) to C5 (neoplastic) during ROSE performed with bronchoscopic or percutaneous sampling procedures of thoracic lesions in a large series of consecutive cases. This retrospective single-center study evaluated 2282 consecutive ROSEs performed on 1827 patients from January 2016 to December 2020 in 994 cases of transbronchial needle aspiration (TBNA) in peripheral pulmonary lesions, in 898 transthoracic FNAs, in 318 ultrasound-guided TBNAs, in 50 conventional TBNAs and in 22 endobronchial TBNAs. False positive and false negative cases of ROSE were 43 (1.88%) and 73 (3.2%), respectively, when compared with the definitive diagnosis. The sensitivity, specificity and the positive and negative prognostic values of ROSE were 94.84%, 95.05%, 96.89% and 91.87%, respectively. Overall concordance between ROSE and the final diagnosis was 0.8960 (Cohen's kappa). No significant differences were observed in terms of sampling procedures and type and location of the lesions. A tiered classification scheme of ROSE from C1 to C5 during bronchoscopic and percutaneous sampling procedures is helpful in effectively guiding clinical management of patients with thoracic lesions.

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

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is a standard, evidence-based classification system for salivary gland fine-needle aspiration (SG-FNA). Since it was published in 2018, many researchers across the world have applied this uniform reporting system to their cohorts.

METHODS

The authors comprehensively reviewed cohort studies conducted since publication of the MSRSGC and performed a meta-analysis. The risk of neoplasm and the risk of malignancy (ROM) were calculated for each diagnostic category, and their diagnostic efficacy was evaluated.

RESULTS

Thirty-five studies were included in the meta-analysis. The total number of SG-FNAs was 10,706, and 7168 of those had histopathologic follow-up. The ROM for each category was: nondiagnostic, 11.4%; nonneoplastic, 10.9%; atypia of undetermined significance, 30.5%; neoplasm-benign, 2.8%; neoplasm-salivary gland neoplasm of uncertain malignant potential, 37.7%; suspicious for malignancy, 83.8%; and malignant, 97.7%. Low-level heterogeneity was observed in ROM estimation. The sensitivity, specificity, and diagnostic odds ratio for differentiating malignant and benign lesions were 88.0%, 98.5% and 520.3, respectively.

CONCLUSIONS

The reporting of SG-FNA using the MSRSGC demonstrated high diagnostic accuracy. The ROM for each category was generally concordant with the recommendations, except for the suspicious for malignancy category, which was significantly higher than the reference value. The tiered, standardized classification system would benefit the clinical management of salivary gland lesions.