Cystic major salivary gland lesions: Utilizing fine needle aspiration to optimize the clinical management of a broad and diverse differential diagnosis

Deep learning based ultrasound analysis facilitates precise distinction between parotid pleomorphic adenoma and Warthin tumor

Background

Pleomorphic adenoma (PA), often with the benign-like imaging appearances similar to Warthin tumor (WT), however, is a potentially malignant tumor with a high recurrence rate. It is worse that pathological fine-needle aspiration cytology (FNAC) is difficult to distinguish PA and WT for inexperienced pathologists. This study employed deep learning (DL) technology, which effectively utilized ultrasound images, to provide a reliable approach for discriminating PA from WT.

Methods

488 surgically confirmed patients, including 266 with PA and 222 with WT, were enrolled in this study. Two experienced ultrasound physicians independently evaluated all images to differentiate between PA and WT. The diagnostic performance of preoperative FNAC was also evaluated. During the DL study, all ultrasound images were randomly divided into training (70%), validation (20%), and test (10%) sets. Furthermore, ultrasound images that could not be diagnosed by FNAC were also randomly allocated to training (60%), validation (20%), and test (20%) sets. Five DL models were developed to classify ultrasound images as PA or WT. The robustness of these models was assessed using five-fold cross-validation. The Gradient-weighted Class Activation Mapping (Grad-CAM) technique was employed to visualize the region of interest in the DL models.

Results

In Grad-CAM analysis, the DL models accurately identified the mass as the region of interest. The area under the receiver operating characteristic curve (AUROC) of the two ultrasound physicians were 0.351 and 0.598, and FNAC achieved an AUROC of only 0.721. Meanwhile, for DL models, the AUROC value for discriminating between PA and WT in the test set was from 0.828 to 0.908. ResNet50 demonstrated the optimal performance with an AUROC of 0.908, an accuracy of 0.833, a sensitivity of 0.736, and a specificity of 0.904. In the test set of cases that FNAC failed to provide a diagnosis, DenseNet121 demonstrated the optimal performance with an AUROC of 0.897, an accuracy of 0.806, a sensitivity of 0.789, and a specificity of 0.824.

Conclusion

For the discrimination of PA and WT, DL models are superior to ultrasound and FNAC, thereby facilitating surgeons in making informed decisions regarding the most appropriate surgical approach.

Cell block preparation as an adjunctive tool after fine-needle aspiration cytology for screening oral and maxillofacial diseases

OBJECTIVE

To describe the use of cell block (CB) preparation from fine-needle aspiration cytology for diagnosing oral and maxillofacial diseases.

STUDY DESIGN

We performed a retrospective analysis of 568 samples collected by our laboratory for CB preparation from fine-needle aspiration cytology of the oral and maxillofacial region between January 2001 and October 2021. We performed cytologic diagnoses and compared them with the available histopathologic diagnoses to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CB preparation for identifying malignant lesions.

RESULTS

The most frequent diagnosis was pleomorphic adenoma (n = 44, 7.7%), followed by metastatic squamous-cell carcinoma (n = 28, 4.9%) and odontogenic keratocyst (n = 26, 4.6%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CB preparation, which revealed detailed morphologic and architectural patterns, were 70.0%, 100.0%, 100.0%, 62.5%, and 80.0%, respectively.

CONCLUSIONS

Cell block preparation from fine-needle aspiration cytology of the oral and maxillofacial region may be a useful adjunctive diagnostic tool for diagnosing oral and maxillofacial diseases because it reveals morphologic and architectural patterns similar to those shown on histopathologic slides, leading to the better categorization of diseases.

Is the combined use of ultrasonography (USG) and fine needle aspiration biopsy (FNAB) safe in parotis masses? Retrospective comprehensive comparison of 123 cases

OBJECTIVES

The purpose of the study was to compare final pathology results with ultrasonography (USI) and fine needle aspiration biopsy (FNAB) results in parotis masses.

METHODS

A total of 123 patients with primary parotis mass who applied to our center between 2010 and 2020 were selected for the study. Among these, 100 patients with preoperative USI, preoperative FNAB, and postoperative final pathology were included in the study. USI, FNAB, pathology results, surgery types, and demographic characteristics of the patients were analyzed.

RESULTS

According to the postoperative final pathology, preoperative USI sensitivity was found to be 100%, specificity was 55, positive predictive value was 84.31%, negative predictive value was 100%, and accuracy was 86.89%. Preoperative FNAB had a sensitivity of 85.7%, a specificity of 92.1%, a positive predictive value of 82.1%, a negative predictive value of 90.2%, and a diagnostic accuracy of 89.3%, according to the postoperative final pathology.

CONCLUSION

Preoperative USI and preoperative FNAB are very valuable diagnostic tools in the evaluation of parotis lesions. When used together, they provide highly accurate and important data for the surgeon.

The use of diagnostic patterns for interventional cytopathology during rapid on-site evaluation and final classification

Pathologist-performed fine-needle aspiration, or interventional cytopathology, is a minimally invasive, highly accurate technique for sampling and diagnosing palpable lesions. Utilizing cytomorphologic patterns during rapid onsite evaluation (ROSE) and final classification is one of many strategies that an interventional cytopathologist can employ to simplify the diagnostic approach. Herein, we provide an overview of the salient cytomorphologic patterns encountered in common specimens obtained by the interventional cytopathologist, including major salivary glands, the thyroid gland, and superficial lymph nodes. The topics covered should provide a primer for those interested in utilizing a site-specific, pattern-based approach to cytopathologic evaluation. In summary, cytomorphologic patterns can be used during ROSE to establish adequacy, build a differential diagnosis, and to appropriately triage the specimen for additional investigation, such as microbiology cultures, a liquid-based preparation, a cell block preparation, flow cytometry, chemical analysis, or molecular diagnostic tests. Finally, this approach can be applied at the time of diagnosis to suggest additional ancillary studies, such as immunohistochemistry, and to inform accurate and definitive classification.

Mucoepidermoid carcinoma: Analysis of 76 cytologic cases and correlation with histologic grade

BACKGROUND

Mucoepidermoid carcinoma (MEC) is the most common salivary gland (SG) malignancy. In this study, the author undertook analysis of a large collection of MEC cytologic cases.

MATERIALS AND METHODS

Cytopathology files were searched for MEC cases with histopathologic confirmation. Fine-needle aspiration (FNA) smears used standard technique.

RESULTS

Seventy-six cases (63 patients [M:F = 1:1; age range, 23-87 years; mean age, 58 years]) met inclusion criteria. Aspirates were primary (54 [71%]), metastatic (18 [24%]), and locally recurrent (4 [5%]). FNA sites included parotid gland (49 [64%]), regional lymph nodes (11 [14%]), submandibular gland (5 [7%]), inner canthus of eye (2 [3%]), and lung (2 [3%]); and single specimens from palate, jaw, shoulder, paranasal sinus, floor of mouth, ear canal, and effusion. Cytologic diagnoses included MEC (30 cases [39%]), suspicious for MEC (16 [21%]), non-MEC carcinoma (9 [12%]), suspicious for malignancy (SM) (2 [3%], malignant (M) (1 [1%]), SG and/or suspicious SG neoplasm (7 [8%]), atypical (3 [5%]), nonneoplastic (5 [6%]), nondiagnostic (2 [3%]), and benign SG neoplasm (1 [1%]). A total of 26% of low-grade (LG) cases were diagnosed as malignant in contrast to 87% malignant in high-grade (HG) cases. Cytomorphology depended on tumor grade. LG MEC contained intra- and/or extra-cellular mucin and more uniform cell and/or nuclear morphology, whereas cytologic atypia, anisonucleosis, and keratotic cells were more typical of HG tumors.

CONCLUSION

A malignant (M) or suspicious for malignancy (SM) cytologic interpretation was made in 76% of mucoepidermoid carcinoma (MEC) cases. In contrast to high-grade MEC (97% identified as M/SM), only 59% of low-grade (LG) MEC cases were interpreted as such, illustrating the continued diagnostic challenge posed by LG MEC using fine-needle aspiration biopsy.

Secretory carcinoma of the salivary gland, a rare entity: An international multi-institutional study

BACKGROUND

Secretory carcinoma (SC) of the salivary gland is a rare entity with limited published literature on cytomorphology. The authors present the largest cohort to date of SC fine‐needle aspiration (FNA) cases.

METHODS

FNA cases of histologically confirmed SC were retrospectively retrieved from 12 academic institutions in the United States, Italy, Finland, and Brazil. The collated data included patient demographics, imaging findings, cytopathologic diagnoses according to the Milan System for Reporting Salivary Gland Cytopathology, cytomorphologic characteristics, and immunohistochemical/molecular profiles.

RESULTS

In total, 40 SCs were identified (male‐to‐female ratio, 14:26) in patients with a mean age of 52 years (age range, 13‐80 years). Ultrasound imagining revealed a hypoechoic, ovoid, poorly defined, or lobulated mass. The most common primary site was the parotid gland (30 of 40 tumors). Regional lymph node metastasis (9 patients) and distant metastasis (4 patients; brain, liver, lungs, and mediastinum) were noted. Two patients died of disease. FNA smears were cellular and demonstrated mainly large, round cells with intracytoplasmic vacuoles or granules and round‐to‐oval nuclei with smooth nuclear contour, minimal irregularities, and prominent nucleoli arranged predominantly in clusters, papillary formations, and single cells. The background was variable and contained inflammatory cells, mucin, or proteinaceous material. The diagnoses were malignant (19 of 38 tumors; 50%), suspicious for malignancy (10 of 38 tumors; 26%), salivary gland neoplasm of uncertain malignant potential (7 of 38 tumors; 18%), and atypia of undetermined significance (2 of 38 tumors; 6%) according to the Milan System for Reporting Salivary Gland Cytopathology. Two malignant cases (2 of 40 tumors; 5%) were metastases. The neoplastic cells were immunoreactive for S100 (23 of 24 tumors), mammaglobin (18 of 18 tumors), GATA‐3 (13 of 13 tumors), AE1/AE3 (7 of 7 tumors), and vimentin (6 of 6 tumors). ETV6‐NTRK3 fusion was detected in 32 of 33 tumors by fluorescence in situ hybridization (n = 32) and next‐generation sequencing (n = 1).

CONCLUSIONS

Familiarity with cytomorphologic features and the immunohistochemical/molecular profile of SC can enhance diagnostic accuracy.;

Secretory carcinoma of the salivary gland, which may manifest with diverse cytomorphology, mammaglobin expression, and ETV6 rearrangement or ETV6‐NTRK3 fusion, was investigated along with cytomorphologic features to facilitate an accurate diagnosis. The results indicated that familiarity with these features and with the immunohistochemical/molecular profile of secretory carcinoma of the salivary gland enhanced diagnostic accuracy.

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.

Application of the Milan System for Reporting Salivary Gland Cytopathology to cystic salivary gland lesions

BACKGROUND

Cystic salivary gland lesions present diagnostic challenges on fine-needle aspiration (FNA) specimens that are related to sampling limitations and a broad differential diagnosis. This study evaluated the benefit of applying the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) to a series of cystic salivary gland lesions.

METHODS

The pathology archives at the Johns Hopkins Hospital were searched to identify cystic salivary gland FNA specimens over a 19-year period (2000-2018). Patient demographics, cytomorphologic features, and clinical and surgical follow-up were recorded. The MSRSGC was applied to the cases. The risk of malignancy (ROM) and the risk of neoplasia (RON) were calculated for each category.

RESULTS

One hundred seventy-eight cases were identified (96 males and 82 females) with a mean age of 53 years (range, 4-90 years). After the MSRSGC was applied, there were 52 nondiagnostic cases (29.2%), 80 nonneoplastic cases (44.9%), 35 cases of atypia of undetermined significance (AUS; 19.7%), 3 benign neoplasms (1.7%), 3 salivary gland neoplasms of uncertain malignant potential (SUMP; 1.7%), 4 cases suspicious for malignancy (SFM; 2.2%), and 1 malignant case (0.6%). One hundred fifty-six of the 178 patients (87.6%) had follow-up data available. The RON and ROM values for cases with surgical follow-up were 33.3% (3 of 9) and 22.2% (2 of 9) for the nondiagnostic category, 42.9% (9 of 21) and 19% (4 of 21) for the nonneoplastic category, 76.5% (13 of 17) and 29.4% (5 of 17) for the AUS category, 100.0% (2 of 2) and 50.0% (1 of 2) for the SUMP category, and 100% (2 of 2) and 100% (2 of 2) for the SFM category, respectively.

CONCLUSIONS

Applying the MSRSGC to cystic salivary gland lesions improves patient management by preventing unnecessary surgery for nonneoplastic conditions. The ROM was highest in the SFM category (100%), which was followed by the SUMP, AUS, nondiagnostic, and nonneoplastic categories. Less than adequate specimens may increase the diagnosis of AUS.

Risk stratification and clinical outcome in the atypia of undetermined significance category in the Milan System for Reporting Salivary Gland Cytopathology

BACKGROUND

Atypia of undetermined significance (AUS) is a category of the Milan System for Reporting Salivary Gland Cytopathology that refers to salivary gland fine-needle aspiration (FNA) specimens that cannot be definitively diagnosed as neoplastic or nonneoplastic.

METHODS

The AUS FNA samples were selected from a large academic institution from 2008 through 2018. The AUS cases were divided into 6 subgroups. The risk of malignancy (ROM), risk of neoplasm (RON), and clinical outcomes for each subgroup were evaluated.

RESULTS

A total of 123 cases were found (76 males and 47 females with a mean age of 62 years [range, 6-94 years]). The parotid gland was the most common FNA site (103 cases), followed by the submandibular gland (9 cases). The overall RON and ROM were 63% and 47%, respectively. Among the subgroups, salivary gland lymph nodes or lymphoid lesions was the most common diagnosis (42%), whereas mucinous cystic lesions with no or a scant epithelial component was the least common (2%). The specimens with preparation artifacts category had the highest RON and ROM (100% for both), whereas the reactive and reparative atypia indefinite for a neoplasm category had the lowest RON and ROM (7% for both). The salivary gland lymph nodes or lymphoid lesions indefinite for a lymphoproliferative disorder category had the second highest RON and ROM at 77% and 74%, respectively.

CONCLUSIONS

The overall RON and ROM for the AUS category were 63% and 47%, respectively. The RON and ROM varied among the different AUS subgroups, being highest in the specimens with preparation artifacts category and lowest in the reactive and reparative atypia category, thereby demonstrating the importance of subgrouping in the AUS specimens.

An audit of cytopathology in the oral and maxillofacial region: 18 years of experience

INTRODUCTION

The aim of this study was to perform an audit of oral and maxillofacial specimens submitted for cytological diagnosis to verify the importance of this complementary examination.

METHODS

A retrospective analysis of our institutional cytopathology database was performed over an 18-year period. Clinical information and cytological data were collected. Associations between independent variables and outcomes were assessed using the Pearson χ² test or Fisher's test, with a 5% significance level. When available, the histological diagnosis was compared with cytological diagnosis to identify the percentage of agreement and the specificity, sensitivity and accuracy of cytology in identifying malignant neoplasms.

RESULTS

A total of 1082 cases were identified, which included 65 different cytological diagnoses. Exfoliative cytology (EC) was performed in 312 cases (29.1%) and fine needle aspiration cytology (FNAC) in 770 cases (70.9%). EC was mainly employed to diagnose oral infectious diseases (P < 0.001) and FNAC to diagnose neoplasms, cystic, reactive and miscellaneous lesions (P < 0.001). Cell-block was performed in 555 FNAC cases (51.3%). Panoptic, Papanicolaou and haematoxylin-eosin staining were performed in FNAC and periodic acid-Schiff in EC (P < 0.001). In 211 cases (19.5%), the histological diagnosis was available and the percentage agreement with the cytological diagnosis was 41.2%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy to identify malignant neoplasms were 84.6%, 100%, 100%, 77.8% and 90.0%, respectively.

CONCLUSIONS

EC was mainly performed for diagnosis of infectious diseases and FNAC for diagnosis of salivary gland tumours, odontogenic lesions, reactive lesions and cervical metastasis.

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.

Oncocytic mucoepidermoid carcinoma (OMEC) of the parotid gland in a 12-year-old patient: A diagnostic challenge on cytology

Mucoepidermoid carcinoma is the most common malignant salivary gland neoplasm comprising approximately 10% of all tumours of the major salivary gland. Owing to a plethora of morphological variations, it poses a diagnostic challenge on fine-needle aspiration cytology. Oncocytic variant of mucoepidermoid carcinoma is a rare subtype seen in the age group of 20-80 years. It is crucial to make the correct diagnosis on cytology as it has therapeutic implications. Oncocytes can be present in a wide range of salivary gland lesions ranging from non-neoplastic conditions to benign and malignant lesions. We report a case of oncocytic mucoepidermoid carcinoma of the parotid gland in a 12-year-old boy which is the youngest age reported for the same. On cytology, this case was initially diagnosed as Warthin's tumour and was supported by radiology. However, histomorphological findings clinched the diagnosis of an oncocytic variant of mucoepidermoid carcinoma with the aid of immunohistochemistry.

Assessing the diagnostic accuracy for pleomorphic adenoma and Warthin tumor by employing the Milan System for Reporting Salivary Gland Cytopathology: An international, multi-institutional study

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has established distinct diagnostic categories for reporting cytopathological findings, and each is associated with a defined risk of malignancy (ROM). However, the ROM is applied at the overall category level and is not specific for particular morphological entities within a category. Here, the diagnostic performance of the MSRSGC for pleomorphic adenoma (PA) and Warthin tumor (WT) is reported.

METHODS

The pathology archives of 11 institutions from 4 countries were retrospectively searched to identify all salivary gland fine-needle aspiration (FNA) biopsies with a differential or definitive diagnosis of PA or WT and all resection specimens with a diagnosis of PA or WT; only paired cases were included. All FNA diagnoses were retrospectively classified according to the MSRSGC.

RESULTS

A total of 1250 cases met the inclusion criteria, and they included 898 PA cases and 352 WT cases. The ROM in the benign neoplasm category was 3.0% and 1.3% for cases with a differential or definitive diagnosis of PA and WT, respectively. The ROM in the salivary gland neoplasm with uncertain malignant potential (SUMP) category was 2.7% and 18.8% for PA and WT, respectively (P = .0277). The diagnostic accuracy for PA and WT was 95.1% and 96.1%, respectively.

CONCLUSIONS

The diagnostic accuracy for PA and WT on FNA is high. Furthermore, these findings highlight the difference in the ROMs associated with 2 specific differential diagnoses in the SUMP category: basaloid neoplasms and oncocytoid neoplasms.

The effect of antiretroviral therapy on fine-needle aspiration of salivary gland masses in HIV-infected patients

BACKGROUND

South Africa has a very high prevalence of HIV/AIDS. Salivary gland lesions are common in HIV-infected patients. The aim of this study was to determine the pathologic entities diagnosed on fine-needle aspiration (FNA) of salivary gland masses in an HIV-infected study population that now has free access to antiretroviral (ARV) therapy and how this differs from the pathologic entities before the advent of widespread ARV availability, and if the Milan system for reporting salivary gland cytopathology (MSRSGC) can be applied to HIV-infected patients.

METHODS

A retrospective review was performed on confirmed HIV-infected patients who underwent FNA of salivary gland masses over a two-year period.

RESULTS

A total of 360 patients underwent FNA of salivary gland masses within the designated time frame, 58.3% (210) females and 41.7% (150) males. Patient ages ranged from 7 months to 67 years with a mean age of 36.9 years. The parotid gland was the most biopsied salivary gland at 55.3% (199). The most common diagnosis made in patients on antiviral therapy was lymphoepithelial cyst while that in patients not on antiviral therapy was infectious (including abscess and mycobacterial infection). The most frequent neoplasms were non-Hodgkin lymphoma, pleomorphic adenoma and squamous-cell carcinoma.

CONCLUSION

Patients on ARV therapy had higher CD4 counts, fewer infectious lesions, and more reactive and benign salivary gland lesions. Patients not on treatment had significantly lower CD4 counts and were frequently diagnosed with infectious processes. The MSRSGC is well-suited for use in HIV-infected patients.

Prediction of Malignancy in Salivary Gland Tumors by a New Cytology Reporting System

OBJECTIVES

The aim of this study was to analyze the risk of malignancy in salivary gland tumors on the basis of the Milan System for Reporting Salivary Gland Cytopathology.

METHODS

A retrospective review was performed of the charts of patients with salivary gland tumors in whom the final diagnosis was confirmed by surgical excision. Preoperative fine needle aspiration results were categorized according to the Milan System for Reporting Salivary Gland Cytopathology: non-diagnostic (category I), nonneoplastic (category II), atypia of undetermined significance (category III), neoplasm (category IV), suspicious for malignancy (category V), and malignant (category VI). Fine needle aspiration and final diagnosis were compared, and the risk of malignancy and operative/oncological outcomes were analyzed.

RESULTS

A total of 288 patients were enrolled in this study. Postoperative histopathologic salivary gland malignancies were found in 30 (10.4%) patients. Risk of malignancy was 7.1%, 0%, 48.0%, 4.8%, 88.7%, and 100% in categories I, II, III, IV, V, and VI, respectively. The most common malignant tumor in category III was salivary duct carcinoma (37.5%), followed by acinic cell carcinoma (25.0%), mucoepidermoid carcinoma (25.0%), and squamous cell carcinoma (12.5%). The 5-year survival rate of patients with malignant tumors showed no statistical difference between category III and category V/VI (P = .140). Risk of malignancy was 88.9% and 100% in category V and VI, respectively.

CONCLUSIONS

A half of atypia of undetermined significance (category III) cases were malignant. Once diagnosed, the prognosis of malignant tumor in category III was similar with that in category V/VI.

Salivary Gland FNA Diagnostics in a Real-Life Setting: One-Year-Experiences of the Implementation of the Milan System in a Tertiary Care Center

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was introduced in 2018 following other organ specific cytopathological reporting systems and it aimed at bringing a practical, evidence-based, user-friendly classification system with characterization and management algorithms. At the Department of Pathology, Fimlab Laboratories, Tampere, Finland all salivary fine needle aspirations (FNAs) have been given cytopathological diagnoses according to the MSRSGC since January 2018. Analyses of a one-year-period (January 2018–December 2018) consisted of 183 salivary FNA samples from 138 patients with correlation to histopathology in 90 cases with surgical follow-up. The MSRSGC performance in patient based analysis was as follows: accuracy was 90.9%, sensitivity was 61.5%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 89.4%, respectively. Risks of malignancy (ROMs) in MSRSGC categories were: 0.0% (0/15) in non-diagnostic category, 100.0% (1/1) in non-neoplastic category biased by only one falsely-negative lymphoma case, 14.3% (1/7) in atypia of undetermined significance category, 0.0% (0/28) in benign neoplasm category, 27.3% (3/11) in neoplasm of uncertain malignant potential category, and 100% for both suspicious for malignancy (4/4) and malignancy (4/4) categories, respectively. The MSRSGC has been proven as a reliable classification system in salivary gland FNA routine diagnostics in a tertiary care center.

Mucoepidermoid carcinoma, acinic cell carcinoma, and adenoid cystic carcinoma on fine-needle aspiration biopsy and The Milan System: an international multi-institutional study

BACKGROUND

We evaluated the diagnostic accuracy (DA), risk of neoplasm (RON), and risk of malignancy (ROM) for the commonly encountered malignant salivary gland tumors mucoepidermoid carcinoma (MECa), acinic cell carcinoma (ACCa), and adenoid cystic carcinoma (ADCa) applying The Milan System for Reporting Salivary Gland Cytology (MSRSGC).

MATERIALS AND METHODS

The cytology archives from 2007 to 2017 of 9 academic institutions were searched for salivary gland FNAs for the following key words mentioned either in the principal and/or differential diagnosis: MEC, ACCa, and ADCa. The original cytology diagnosis was retrospectively classified according to the MSRSGC. Patient demographics, biopsy site, and available surgical follow-up were recorded. The final analysis included only cases with surgical follow-up.

RESULTS

A total of 212 salivary gland FNAs were included. Based on retrospective reclassification according to MSRSGC, 97 of 212 (46%) FNA cases carried a diagnosis of malignancy specific for either MECa, ACCa, or ADCa. In the remaining 115 cases, 24 of 212 (11%) were reclassified as suspicious for malignancy (SM) and 91 of 212 (43%) as salivary gland neoplasm of uncertain malignant potential (SUMP). The DA for MECa, ACCa, and ADCa was 78.7%, 75% and 89%, respectively. The RON was 100% for all 3 tumors and the ROM was 93.6% for MECa, 96.8% for ACCa, and 94.4% for ADCa.

CONCLUSIONS

The DA of 78.7% for MECa, 75% for ACCa, and 89% for ADCa is reasonable in FNA specimens. Although the management of definitive cases of malignancy remains unchanged, the MSRSGC provides a ROM for SM and SUMP categories, which can improve patient management.

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.

Application of the Milan System for Reporting Submandibular Gland Cytopathology: An international, multi-institutional study

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is a 6-tier diagnostic category system with associated risks of malignancy (ROMs) and management recommendations. Submandibular gland fine-needle aspiration (FNA) is uncommon with a higher frequency of inflammatory lesions and a higher relative proportion of malignancy, and this may affect the ROM and subsequent management. This study evaluated the application of the MSRSGC and the ROM for each diagnostic category for 734 submandibular gland FNAs.

METHODS

Submandibular gland FNA cytology specimens from 15 international institutions (2013-2017) were retrospectively assigned to an MSRSGC diagnostic category as follows: nondiagnostic, nonneoplastic, atypia of undetermined significance (AUS), benign neoplasm, salivary gland neoplasm of uncertain malignant potential (SUMP), suspicious for malignancy (SM), or malignant. A correlation with the available histopathologic follow-up was performed, and the ROM was calculated for each MSRSGC diagnostic category.

RESULTS

The case cohort of 734 aspirates was reclassified according to the MSRSGC as follows: nondiagnostic, 21.4% (0%-50%); nonneoplastic, 24.2% (9.1%-53.6%); AUS, 6.7% (0%-14.3%); benign neoplasm, 18.3% (0%-52.5%); SUMP, 12% (0%-37.7%); SM, 3.5% (0%-12.5%); and malignant, 13.9% (2%-31.3%). The histopathologic follow-up was available for 333 cases (45.4%). The ROMs were as follows: nondiagnostic, 10.6%; nonneoplastic, 7.5%; AUS, 27.6%; benign neoplasm, 3.2%; SUMP, 41.9%; SM, 82.3%; and malignant, 93.6%.

CONCLUSIONS

This multi-institutional study shows that the ROM of each MSRSGC category for submandibular gland FNA is similar to that reported for parotid gland FNA, although the reported rates for the different MSRSGC categories were variable across institutions. Thus, the MSRSGC can be reliably applied to submandibular gland FNA.

Diagnostic Approach to Fine Needle Aspirations of Cystic Lesions of the Salivary Gland

Fine needle aspiration (FNA) has diagnostic and therapeutic value in the management of salivary gland cysts. Rendering an accurate diagnosis from an aspirated salivary gland cyst is challenging because of the broad differential diagnosis, possibility of sampling error, frequent hypocellularity of specimens, morphologic heterogeneity, and overlapping cytomorphology of many cystic entities. To date, there have been no comprehensive review articles providing a practical diagnostic approach to FNA of cystic lesions of salivary glands. This article reviews the cytopathology of salivary gland cysts employing 2017 World Health Organization terminology, addresses the accuracy of FNA, and presents The Milan System approach for reporting in cystic salivary gland cases. The utility of separating FNA specimens from salivary gland cysts, based upon the presence of mucin and admixed lymphocytes in cyst fluid is demonstrated. A reliable approach to interpreting FNA specimens from patients with cystic salivary gland lesions is essential to accurately determine which of these patients may require subsequent surgery.