Cytological features of a lymphoepithelial cyst of the salivary gland with application of the second edition of Milan System for Reporting Salivary Gland Cytopathology

Lymphoepithelial cysts (LECs) of the salivary glands are relatively rare, benign cystic lesions. Characteristic histopathological features of LEC include presence of well-circumscribed unilocular cysts surrounded by dense lymphoid tissue with lymphoid follicles. These cysts are lined by a combination of squamous, ciliated, columnar and mucous epithelia. Fine-needle aspiration (FNA) cytology is the standard preoperative diagnostic procedure for salivary gland lesions. Although the cytological diagnosis of cystic salivary gland lesions is difficult, the use of Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) in the cytodiagnosis of cystic salivary gland lesions has been reported. However, only a few studies have described the cytological features of LEC. To the best of our knowledge, the present study reviewed the cytological features of a case series of LEC and evaluated the application of MSRSGC for the first time. This retrospective study included 13 patients with LEC of the salivary glands who underwent pre-operative FNA followed by surgical resection of the cyst. All the lesions were present in the parotid gland. Cytological analysis revealed no epithelial cell component in eight patients (62.5%) along with a proteinaceous background containing lymphocytes and/or foamy cells. Non-keratinising squamous epithelium was observed in three patients. Amylase crystalloids were noted in two patients. None of the patients were cytodiagnosed with LEC. Eight, three, one and one patients were categorised as MSRSGC I, II, III, and IVa, respectively. The results of the present study demonstrated that cytodiagnosis of LEC was difficult due to the absence of epithelial component in 62.5% of the specimens. However, evaluation of its benignity was not difficult. Thus, it can be summarized that MSRSGC may be useful for cytological evaluation of LECs.

Clinical diagnostic utility of ultrasound-guided fine needle aspiration biopsy in parotid masses

BACKGROUND

Fine needle aspiration (FNA) is a common diagnostic tool used in the initial evaluation of parotid masses. In the literature, variable diagnostic accuracy of FNA is reported. Therefore, when considering clinical management of these patients, the utility of FNA is unclear. The aim of this study was to determine the capability of ultrasound-guided FNA to differentiate between benign and malignant neoplasms. Further, the way in which FNA results affect clinical decision-making was assessed.

METHODS

Retrospective data were collected for all patients who underwent parotidectomy at a large Canadian tertiary care center between 2011 and 2016. Patient demographics, preoperative imaging reports, preoperative FNA results, and final pathological diagnosis were analyzed.

RESULTS

Of the 199 patients who underwent parotidectomy, 184 had preoperative ultrasound-guided FNA. There were a total of 13 non-diagnostic FNAs. In diagnosing malignancy, FNA had a sensitivity and specificity of 71.4% and 98.7%, respectively. The positive predictive value (PPV) was 83.3%. The negative predictive value was 97.5%. Of the non-diagnostic FNAs, 2 out of 13 (15.4%) were deemed malignant neoplasms on final pathology.

CONCLUSION

FNA is a useful adjunct in the work-up of parotid masses, but it should be used with caution. Due to limited sensitivity, it should not be relied upon as the sole determinant of a surgeon's management plan.

MRI-based radiomics for predicting histology in malignant salivary gland tumors: methodology and "proof of principle"

Defining the exact histological features of salivary gland malignancies before treatment remains an unsolved problem that compromises the ability to tailor further therapeutic steps individually. Radiomics, a new methodology to extract quantitative information from medical images, could contribute to characterizing the individual cancer phenotype already before treatment in a fast and non-invasive way. Consequently, the standardization and implementation of radiomic analysis in the clinical routine work to predict histology of salivary gland cancer (SGC) could also provide improvements in clinical decision-making. In this study, we aimed to investigate the potential of radiomic features as imaging biomarker to distinguish between high grade and low-grade salivary gland malignancies. We have also investigated the effect of image and feature level harmonization on the performance of radiomic models. For this study, our dual center cohort consisted of 126 patients, with histologically proven SGC, who underwent curative-intent treatment in two tertiary oncology centers. We extracted and analyzed the radiomics features of 120 pre-therapeutic MRI images with gadolinium (T1 sequences), and correlated those with the definitive post-operative histology. In our study the best radiomic model achieved average AUC of 0.66 and balanced accuracy of 0.63. According to the results, there is significant difference between the performance of models based on MRI intensity normalized images + harmonized features and other models (p value < 0.05) which indicates that in case of dealing with heterogeneous dataset, applying the harmonization methods is beneficial. Among radiomic features minimum intensity from first order, and gray level-variance from texture category were frequently selected during multivariate analysis which indicate the potential of these features as being used as imaging biomarker. The present bicentric study presents for the first time the feasibility of implementing MR-based, handcrafted radiomics, based on T1 contrast-enhanced sequences and the ComBat harmonization method in an effort to predict the formal grading of salivary gland carcinoma with satisfactory performance.

Pitfalls in Salivary Gland Cytology

BACKGROUND

Salivary gland lesions possess diagnostic challenges on fine-needle aspiration (FNA) material. They are relatively uncommon, yet present with a wide spectrum of cytomorphology. Herein, we review common salivary gland neoplasms, their cytomorphologic features, their diagnostic pitfalls, and ancillary studies helpful in achieving an accurate diagnosis.

SUMMARY

There are many cytomorphologic overlaps between benign and malignant salivary gland entities. Moreover, metaplasia, cystic changes, and degenerative changes are common findings adding to diagnostic dilemmas. These complicating factors contribute to a minute risk of malignancy in salivary gland lesions that are interpreted as benign on FNA. In rare cases, even malignant salivary gland neoplasms are misinterpreted as benign on aspirated material due to the many cytomorphologic overlaps. For example, benign and malignant neoplasms containing stroma such as myoepithelioma and adenoid cystic carcinoma may be misinterpreted as pleomorphic adenoma. Moreover, diagnosis of salivary gland neoplasms with basal cell features can be confusing on FNA materials; for example, basal cell adenoma can be misinterpreted as adenoid cystic carcinoma. Mucoepidermoid carcinomas have many different appearances on aspirated material due to variable amounts of mucin, degree of nuclear atypia, cellular content, and squamous metaplasia. Acinic cell carcinoma exhibits large cells with abundant cytoplasm on FNA, which can be mistaken for oncocytic cells in oncocytoma or Warthin tumor. Salivary duct carcinoma shows distinct features of malignancy and thus can be mistaken for secondary tumors involving the salivary glands or other malignant salivary gland tumors. The presence of tumor-associated lymphocytes is another underlying cause of misdiagnosis, especially when considering the differential diagnosis of an intraparotid lymph node. Ancillary studies such as immunohistochemistry and molecular studies are gaining more attention to be utilized on FNA cases. PLAG1 immunostaining, CD117, DOG1, mammaglobin, and androgen receptor (AR) are examples of commonly used immunostains in diagnosis of salivary gland lesions. MYB gene fusion, rearrangements of the MAML2 gene, and ERBB2/HER2 are examples of molecular alterations useful in diagnosis of salivary gland neoplasms. In conclusion, the aim of salivary gland cytology is to differentiate benign entities from the malignant ones and to prevent unnecessary aggressive treatments.

KEY MESSAGES

The diagnostic pitfalls are enormous in salivary gland cytology. Familiarity with cytomorphology of different entities and their cytomorphologic overlaps, and application of ancillary studies improves the diagnostic yield, patient management and prevents unnecessary aggressive procedures.

The Usefulness of Fine Needle Aspiration Cytology in the Management of Parotid Gland Masses at a Tertiary Academic Hospital

Background

Fine needle aspiration cytology (FNAC) is an integral part of the preoperative work-up of parotid tumours.

Aim

To determine the rate of concordance between FNAC and histology following parotidectomy.

Methods

A review of records of patients who had parotidectomy which was preceded FNAC was done. Data collected included patients' demography, presenting symptoms and clinical signs; cytology and post-operative histology results.

Results

Seventy-seven records were found and 14 were excluded. Forty-five (71%: 45/63) of the tumours were benign, 21% (13/63) malignant and 8% (5/63) inflammatory lesions. Forty-one (91.1%: 41/45) of the benign tumours had concordance between FNAC and final histology. Seven (63.6%: 7/11) of FNAC diagnosed malignancies were confirmed on histology.

Conclusion

Around 71% of parotid masses were benign. Painful masses are more likely to be malignant and FNAC is more reliable for the diagnosis of pleomorphic adenoma than rare benign and malignant tumours of the parotid gland.

Ability for fine needle aspiration and frozen section to predict extent of parotidectomy

INTRODUCTION

Several diagnostic modalities with various sensitivity and specificities can be used to evaluate a parotid mass. The aims of this project were to compare the diagnostic actionability, accuracy, and ability to accurately predict extent of surgery for FNA and frozen section during the evaluation of a parotid mass.

METHODS

A retrospective chart review of patients who underwent parotidectomy for a parotid mass from January 1, 2015 to January 30, 2022 was conducted. Actionability was defined as a pathology diagnosis or the histologic grade of a lesion, as this provided clear and useful information for the surgeon to act upon. Diagnostic accuracy was determined by comparing FNA and frozen section results to final pathology. Accuracy of extent of surgery was determined by comparing predicted extent of surgery from the FNA or frozen section result to the extent of surgery predicted by the final pathology.

RESULTS

A total of 626 patients were included in this study. FNA was obtained in 396 (63%) patients, while all neoplasms were evaluated by frozen section analysis. FNA diagnosis was actionable in 318 (80%), while frozen section diagnosis was actionable in 616 (98%) patients. Exactly 294 (92.5%) FNA diagnoses were accurate compared with 600 (98%) frozen section diagnoses. The FNA diagnosis predicted appropriate extent of surgery in 294 (74%) while the frozen section diagnosis predicted appropriate extent of surgery in 600 (96%). Among the 396 patients with FNA, frozen section was significantly more likely to accurately predict appropriate extent of surgery compared with FNA (p < 0.001).

CONCLUSION

Frozen section is more likely to yield actionable and accurate results compared with FNA. Additionally, frozen section is better than FNA in predicting the appropriate extent of surgery.

Topology-based radiomic features for prediction of parotid gland cancer malignancy grade in magnetic resonance images

PURPOSE

The malignancy grades of parotid gland cancer (PGC) have been assessed for a decision of treatment policies. Therefore, we have investigated the feasibility of topology-based radiomic features for the prediction of parotid gland cancer (PGC) malignancy grade in magnetic resonance (MR) images.

MATERIALS AND METHODS

Two-dimensional T1- and T2-weighted MR images of 39 patients with PGC were selected for this study. Imaging properties of PGC can be quantified using the topology, which could be useful for assessing the number of the k-dimensional holes or heterogeneity in PGC regions using invariants of the Betti numbers. Radiomic signatures were constructed from 41,472 features obtained after a harmonization using an elastic net model. PGC patients were stratified using a logistic classification into low/intermediate- and high-grade malignancy groups. The training data were increased by four times to avoid the overfitting problem using a synthetic minority oversampling technique. The proposed approach was assessed using a 4-fold cross-validation test.

RESULTS

The highest accuracy of the proposed approach was 0.975 for the validation cases, whereas that of the conventional approach was 0.694.

CONCLUSION

This study indicated that topology-based radiomic features could be feasible for the noninvasive prediction of the malignancy grade of PGCs.

Fine-Needle Aspiration Cytology in the Diagnosis of Salivary Gland Tumors Before the Milan System: A Ten-Year Experience From a Tertiary Care Center in Greece

Objective The objective of this study was to determine the diagnostic value of fine-needle aspiration cytology (FNAC) for salivary gland tumors. Methodology A retrospective file analysis of patients with salivary gland pathology, attending the Department of Oral and Maxillofacial Surgery of a tertiary care center in Athens, Greece, over a 10-year-long period, was conducted. Sensitivity, specificity, accuracy, positive prognostic value (PPV), and negative prognostic value (NPV) of FNAC for benign and malignant tumors separately were assessed and compared with histology. Results A total of 82 patients (46 male and 36 female) with salivary gland tumors, submitted to both FNAC and histology, were included. The mean age was 55 years. A total of 73 tumors were histologically diagnosed as benign and nine as malignant. FNAC identified 62 benign and seven malignant tumors but was inconclusive in 13 cases. The most common diagnosis of both histology and FNAC was pleomorphic adenoma. FNAC sensitivity, specificity, accuracy, PPV, and NPV were 98.3% and 100%, 87.5% and 100%, 97.1% and 100%, 98.3% and 100%, and 87.5% and 100% for benign and malignant tumors, respectively. Conclusions FNAC is highly sensitive but moderately specific for the preoperative identification of benign salivary gland tumors. Its use as an initial diagnostic modality is warranted, thanks to its safeness, rapidity, and lack of pain.

[Indications for fine-needle aspiration and core needle biopsy for diagnosis of salivary gland tumors]

BACKGROUND

Salivary gland malignancies are rare neoplasms of the head and neck area. Preoperative clinical and imaging assessment of salivary gland masses is challenging. However, preoperative identification of malignancy is crucial for further treatment and for the course of the disease.

OBJECTIVE

This article presents the advantages and disadvantages of fine-needle aspiration cytology (FNAC) and core needle biopsy (CNB). Additionally, the sensitivity and specificity of both methods for predicting malignancy were analyzed. Furthermore, it is discussed which procedure is suitable for the diagnostic work-up of salivary gland tumors.

MATERIALS AND METHODS

This current article summarizes important and recent studies in the field of the diagnostic work-up for salivary gland lesions, with discussion of original articles, metanalyses, and systematic reviews concerning FNAC and CNB.

RESULTS

The sensitivity and specificity of the predictive ability of FNAC for malignancy is described at between 70.0-80.0% and 87.5-97.9%. The pooled sensitivity and specificity for CNB were 92.0-98.0% and 95.0-100.0%, respectively. Tumor cell seeding or facial nerve palsy are very rare complications of both procedures.

CONCLUSION

If malignancy is suspected based on clinical examination or imaging, FNAC or CNB should be performed. FNAC is easy to perform; however, an onsite cytologist is necessary. CNB has a higher sensitivity for routine diagnosis of malignancy; tumor typing and grading is facilitated by preserving the histological architecture. In conclusion, CNB is the procedure of choice in the diagnostic work-up for suspected malignant salivary gland tumors.

Results of 301 Parotidectomies: A Twenty-Year Experience of One Single Institution

To evaluate demographic, clinical, surgical and histopathological results and complications of 301 parotidectomies performed in southern part of Turkey. The results of 297 patients undergoing 301 parotidectomies between 2000 and 2019 were retrospectively reviewed. Four patients underwent bilateral parotidectomy. Age, gender, side and size of lesion, postoperative facial nerve function (FNF) for benign tumors and types of surgery were evaluated. There were 172 male and 125 female patients. The mean age was 52.53 ± 16.67 years (range 11-90 years). Patients with malignant tumor had higher mean age than the patients with benign diseases (p < 0.001) and the mean age of Warthin tumor (WT) patients was significantly higher than pleomorphic adenoma (PA) (p < 0.001). There was a significant male dominancy in WTs than the PAs (p < 0.001). The mean size of the malignant tumors was significantly higher than the benign tumors (p = 0.012). The mean of cigarette smoking value (pack/year) was higher in WTs than the PAs (p < 0.001). WT incidence was slightly higher than PA in between years 2010 and 2019 (p = 0.272) compared to between years 2000 and 2009. Fine needle aspiration biopsy had a sensitivity of 96% and specificity of 78% for the benign tumors. Tumor location (p < 0.001) and tumor size (p = 0.034) had negative effect on the postoperative FNF. The incidence of WT had a significant rise in the last decade. Deep lobe tumors and increased tumor size had effect postoperative FNF. Experience of surgeon is more important than nerve monitoring to prevent facial paralysis. Partial superficial parotidectomy was available methods for small benign tumors in tail of the parotid gland.

The Diagnostic Value of Fine Needle Aspiration Biopsy in Parotid Tumors

The aim of this study was to investigate the diagnostic accuracy rates of the patients who underwent an operation for parotid mass, by comparing their fine needle aspiration biopsy (FNAB) cytology results with the final pathology. A total of 136 patient files of those who applied to Otorhinolaryngology clinic due to parotid mass and underwent parotidectomy procedure between 2010 and 2020 at a tertiary center were scanned retrospectively. Database on patient age, gender, preoperative FNAB results, and final surgical histopathology results was created. The mean age of the patients was 48.26 ± 17.37 Superficial parotidectomy was performed to 108 (79.4%) and total parotidectomy to 28 (20.6%) of the patients. The sensitivity of FNAB was found as 85.2%, specificity as 96.2%, positive predictive value as 85.2%, negative predictive value as 96.2% and accuracy as 94.0%. It is found that FNAB has the high specificity and high negative predictive value with high diagnostic accuracy on detecting preoperative malignancy in parotid gland. We think that FNAB is a significant, necessary and safe method in the diagnosis of parotid lesions in preoperative sense.

Ancillary studies on cell blocks from fine needle aspiration specimens of salivary gland lesions: A multi‐institutional study

Background

Ancillary studies are commonly performed on cell blocks prepared from fine‐needle aspiration (FNA) specimens. There are limited studies in application of ancillary studies on cell blocks from salivary gland (SG) FNAs. This multi‐institutional study evaluates the role of ancillary studies performed on cell blocks in the diagnosis of SG lesions, and their impact on clinical management.

Method

The electronic pathology archives of three large academic institutions were searched for SG FNAs with ancillary studies performed on cell blocks. The patient demographics, FNA site, cytologic diagnosis, ancillary studies, and surgical follow‐up were recorded. If needed, the cytologic diagnoses were reclassified as per the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC).

Results

117 SG FNA cases were identified including 3, 10, 11, 6, 23, 4, and 60 cases in MSRSGC categories I, II, III, IVa, IVb, V, VI, respectively with surgical follow‐up available ranging from 27% to 100% within each category. Ancillary studies including histochemistry, immunocytochemistry (IHC), and in situ hybridization (ISH) were beneficial in 60%–100% of cases in each category. Risk of malignancy was 100% in both the suspicious for malignancy (V) and malignant (VI) categories. Ancillary studies improved diagnosis in 60% of non‐neoplastic cases (II, 6/10), 100% of benign neoplasm cases (IVa, 6/6), and 98.3% of malignant cases (VI, 59/60).

Conclusion

Judicious and case‐based ancillary studies performed on SG FNA cell blocks with sufficient material can improve the diagnostic yield by further characterization of the atypical/neoplastic cells, particularly in MSRSGC categories IVa‐VI.

Indications and Outcomes of Parotidectomy in Saudi Children: Experience From Two Tertiary Centers

Introduction

Children can present with a wide variety of parotid diseases. However, most of them do not require surgical treatment. The indications of parotid surgery in children may differ from those in adults. In this study, we aim to review the indications and outcomes of parotidectomy in our pediatric population.

Methods

Retrospective review of the medical records of patients who underwent parotid surgery at age <18 years in two tertiary centers over a 14-year period.

Results

A total of 18 parotidectomies were performed on 18 patients with a mean age of 13.5 years. All patients presented with a parotid mass. The most common procedure was superficial parotidectomy followed by total parotidectomy. Ten patients were diagnosed with a benign parotid disease (55.6%). The most common benign disease was pleomorphic adenoma. There were eight cases of parotid malignancy constituting 44.4% of all patients and 57% of patients presenting in the age range of 12-17 years. Mucoepidermoid carcinoma was the most common malignancy (six patients). Fine needle aspiration biopsy was performed in 12 children with a sensitivity, specificity, and overall accuracy of 62.5%, 50%, and 58.6%, respectively. The most common complication was temporary facial weakness (33.3%) which resolved in a mean time of 2.5 months. No disease recurrences were identified.

Conclusions

Parotidectomy is uncommon in the pediatric age group. Children with a solid parotid tumor have a higher risk of parotid malignancy when compared to adults. A parotid mass presenting in the second decade of life is more likely to be malignant than benign.

A multi-institutional study of salivary gland cytopathology: Application of the Milan System for Reporting Salivary Gland Cytopathology in Japan

Background

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is a risk‐stratification reporting system that was introduced in 2018. The objective of this multi‐institutional study was to evaluate the utility of the MSRSGC in Japan.

Methods

In total, 1608 fine‐needle aspiration samples with matching histologic diagnoses were retrieved from 12 large institutions in Japan. The diagnostic categories of the MSRSGC were assigned prospectively or retrospectively, and the results were compared with the histologic diagnoses.

Results

The cases were classified as follows: nondiagnostic, 18.1%; non‐neoplastic, 4.1%; atypia of undetermined significance, 11.5%; neoplasm‐benign, 43.7%; salivary gland neoplasm of uncertain malignant potential, 9.6%; suspicious for malignancy, 3.6%; and malignant, 9.4%. The risk of neoplasm and the risk of malignancy in each MSRSGC category were as follows: nondiagnostic, 72.9% and 13.4%, respectively; non‐neoplastic, 15.2% and 9.1%, respectively; atypia of undetermined significance, 77.9% and 24.9%, respectively; neoplasm‐benign, 99% and 1.8%, respectively; salivary gland neoplasm of uncertain malignant potential, 94.8% and 37%, respectively; suspicious for malignancy, 100% and 89.7%, respectively; and malignant, 100% and 99.3%, respectively. The accuracy of the MSRSGC for diagnosing neoplasms was 97.8%, and its accuracy for diagnosing malignancy was 97.3%. Institutions that used Romanowsky‐stained preparations had lower nondiagnostic rates and lower risks of neoplasm and malignancy in the non‐neoplastic category.

Conclusions

The MSRSGC is useful for risk stratification and quality control. Widespread use of the MSRSGC would improve the accuracy of salivary gland cytology and lead to better patient care in Japan.

This is the first multi‐institutional study of a large‐scale application of the Milan System for Reporting Salivary Gland Cytopathology in Japan. It demonstrates the usefulness of the Milan system in the diagnosis of salivary gland lesions and for the quality control of salivary gland cytology results.

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.

Deep Learning for Differentiating Benign From Malignant Parotid Lesions on MR Images

Purpose/Objectives(s)

Salivary gland tumors are a rare, histologically heterogeneous group of tumors. The distinction between malignant and benign tumors of the parotid gland is clinically important. This study aims to develop and evaluate a deep-learning network for diagnosing parotid gland tumors via the deep learning of MR images.

Materials/Methods

Two hundred thirty-three patients with parotid gland tumors were enrolled in this study. Histology results were available for all tumors. All patients underwent MRI scans, including T1-weighted, CE-T1-weighted and T2-weighted imaging series. The parotid glands and tumors were segmented on all three MR image series by a radiologist with 10 years of clinical experience. A total of 3791 parotid gland region images were cropped from the MR images. A label (pleomorphic adenoma and Warthin tumor, malignant tumor or free of tumor), which was based on histology results, was assigned to each image. To train the deep-learning model, these data were randomly divided into a training dataset (90%, comprising 3035 MR images from 212 patients: 714 pleomorphic adenoma images, 558 Warthin tumor images, 861 malignant tumor images, and 902 images free of tumor) and a validation dataset (10%, comprising 275 images from 21 patients: 57 pleomorphic adenoma images, 36 Warthin tumor images, 93 malignant tumor images, and 89 images free of tumor). A modified ResNet model was developed to classify these images. The input images were resized to 224x224 pixels, including four channels (T1-weighted tumor images only, T2-weighted tumor images only, CE-T1-weighted tumor images only and parotid gland images). Random image flipping and contrast adjustment were used for data enhancement. The model was trained for 1200 epochs with a learning rate of 1e-6, and the Adam optimizer was implemented. It took approximately 2 hours to complete the whole training procedure. The whole program was developed with PyTorch (version 1.2).

Results

The model accuracy with the training dataset was 92.94% (95% CI [0.91, 0.93]). The micro-AUC was 0.98. The experimental results showed that the accuracy of the final algorithm in the diagnosis and staging of parotid cancer was 82.18% (95% CI [0.77, 0.86]). The micro-AUC was 0.93.

Conclusion

The proposed model may be used to assist clinicians in the diagnosis of parotid tumors. However, future larger-scale multicenter studies are required for full validation.

Accuracy, predictability and prognostic implications of fine-needle aspiration biopsy for parotid gland tumours: A retrospective case series

OBJECTIVE

To evaluate the precision and utility of fine-needle aspiration (FNA) in differentiating between benign and malignant parotid tumours, and the implications of FNA results on management and outcomes.

DESIGN

Retrospective case series.

SETTING

Tertiary medical centre.

PARTICIPANTS

All adults who underwent preoperative FNA, followed by postoperative histological examination, between 1986 and 2014.

MAIN OUTCOME MEASURES

Differences in clinical management and outcomes of patients with parotid masses in light of FNA results.

RESULTS

We analysed 505 samples from 485 patients. According to histopathological results, preoperative FNA successfully identified benign tumours in 89% of the cases (362/405) and only 59% of malignant tumours (59/100). Overall sensitivity and specificity of FNA in distinguishing between different subtypes of benign lesions were 80% and 99%, respectively, whereas positive predictive value (PPV) and negative predictive value (NPV) were 85% and 98%. Moreover, malignant lesions subtyping had high false-positive and false-negative rates with sensitivity, specificity, PPV and NPV of 44%, 100%, 75% and 99%, respectively. Additionally, when FNA falsely classified malignant tumours as benign, surgeries were inappropriately delayed and the durations of surgeries and hospitalisations were shorter, compared to true malignant FNA results. Interestingly, survival was not affected in falsely benign lesions that were mostly low-grade, conversely non-diagnostic FNA for malignant tumours resulted in decreased survival.

CONCLUSIONS

Our findings highlight the limitations of FNA as a decision-making tool in preoperative evaluation of parotid masses. Clinicians should take into account that FNA is inaccurate for identifying specific subtypes of malignant lesions, which may eventually delay treatment and influence outcome.

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.

Metastases of Cutaneous Squamous Cell Carcinoma Seem to be the Most Frequent Malignancies in the Parotid Gland: A Hospital-Based Study From a Salivary Gland Center

Malignant parotid tumors account for approximately 20% of all parotid lesions. In addition to the various primary parotid lesions there are secondary parotid malignancies, such as metastases or lymphomas. Data on histopathological distribution of all malignancies-including secondary parotid lesions-is limited. Recent evidence indicated a rising surgical incidence of secondary parotid malignancies. This study aims to review the distribution of malignancies in parotid resections from a salivary gland center. A retrospective review of prospectively collected data for all patients who had received parotidectomy between 2014 and 2019 was performed. Histopathological distribution was displayed separately for all parotid malignancies and for primary parotid malignancies. Further, patients` characteristics were compared between benign and malignant parotid lesions and between the two most common malignant parotid lesions. Out of 777 patients, 614 (78.9%) patients had a benign and 164 (21.1%) patients had a malignant parotid lesion. The most common parotid malignancy was metastatic cutaneous squamous cell carcinoma (cSCC) accounting for 35.4% of all parotid malignancies. 71.5% of all malignant lesions were secondary malignancies. Patients with metastatic cSCC were significantly older (p < 0.001) and significantly more likely to be male (p < 0.001) than patients with primary parotid malignancies. No significant difference was found when the lesion size of metastatic cSCC was compared to primary parotid malignancies (p = 0.216). The present study shows the high prevalence of secondary parotid malignancies in patients who had received parotidectomy. Furthermore, it confirms a rising surgical incidence of metastatic cSCC to the parotid gland in a series from a salivary gland center. At this time, parotid surgery for malignant lesions is more likely to be performed for metastases than for primary parotid malignancies.

The role of fine needle aspiration biopsy in deep lobe parotid tumors: Comparison of preoperative cytology and postoperative histopathologic results

PURPOSE

Major salivary gland tumors constitute almost 3% of head and neck tumors. Tumors located exclusively in the deep lobe are not common and 20% of parotid gland tumors originate from deep lobe under the branches of the facial nerve. Accuracy of fine needle aspiration biopsy (FNAB) procedure in salivary gland tumors have been studied extensively, however there isn't any data regarding usefulness of FNAB in tumors located exclusively in deep lobe of parotid gland. In this study we aimed to assess the use of FNAB in deep lobe parotid tumors.

MATERIALS AND METHODS

We retrospectively analyzed 51 patients with deep lobe parotid tumors who underwent surgery in our clinic between January 2013-December 2018. Characteristics of patients were recorded. Preoperative FNAB results and postoperative final histopathologic diagnosis were compared. Statistical analysis was performed using SPSS 24.0 was used for statistical analysis.

RESULTS

The number of patients that met the inclusion criteria was 51. The mean age of patients were 49.2(14-86). In 40 (78.4) of the patients, tumor was reported as benign and in 11 (21.6) patients FNAB diagnosis was suspicious for malignancy, malignant or non-diagnostic. In final histopathologic diagnosis, 42 of the tumors were benign and 9 were malignant. The most common benign tumor type was pleomorphic adenoma which constitutes 27 of the cases (52.9%). Regarding detection of malignant disease, the sensitivity of FNAB was 90.4%, specificity was 77.7%, positive predictive value was 95%, negative predictive value was 63.6%. There was a substantial agreement between FNAB and final histopathologic diagnosis(kappa = 0,628).

CONCLUSIONS

FNAB is a safe and reliable tool to evaluate deep lobe parotid tumors. It is an important part of preoperative surgical planning and can help the surgeon in patient counseling. FNAB with ultrasound guidance is recommended for deep lobe tumors.

A novel clinically-oriented classification of fine-needle aspiration cytology for salivary gland tumors: a 20-year retrospective analysis of 1175 patients

Background

When determining treatment strategy for a salivary gland tumor, assessing histology and malignancy grade before surgery is essential. Several new diagnostic classification systems for salivary gland cytology have recently been proposed. However, none incorporate histology and grade of malignancy.

Methods

We developed a new cytology classification system that incorporates histology and grade of malignancy of salivary gland tumors (OMC classification), consisting of 11 categories. Our OMC classification was applied to 1175 patients who had preoperative cytology and confirmed final pathological diagnosis available from the past 20 years at our hospital (benign tumor: 981 patients, malignant tumor: 194 patients).

Results

Based on the cytology, 729 patients (62.0%) had benign histology (Category 4–1), and 87 patients (7.4%) were diagnosed with grade of malignancy (Category 6–3 + 6–4). Based on the final pathological diagnosis, the accuracy rate of Category 4–1 and Category 6–3 + 6–4 of our classification system was 93.4% and 88.5%, respectively.

Conclusion

Based on the correct diagnosis rate, the inclusion of histology and grade of malignancy in the salivary gland cytology classification was considered feasible. Thus, the OMC classification system is considered a useful tool when determining the treatment strategy for a salivary gland tumor.

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.

Malignant tumours of the parotid gland: management of the neck (including the clinically negative neck) and a literature review

Major salivary gland malignancies are rare, constituting 1%-3% of head-neck tumours. The surgical management of the clinically negative neck (cN0) does not have a univocal consensus yet. We have carried out a retrospective study on 119 cases of malignant parotid tumours that were surgically treated between January 1999 and January 2014. Our aim was to analyse preoperative findings (cytotype, cTNM) and to correlate these with postoperative results (grading, histotype, occult neck metastasis) in patients with parotid tumours to obtain an appropriate indication for neck management. In cN0 patients with a T1, T2 low-grade cancer a wait-and-see approach is preferred. Instead, in cNO patients with high-grade or low-grade T3, T4 tumours an elective neck dissection (END) is always planned. Levels II, III and IV, at least, must be dissected. The decision to dissect level V or I depends on the location of the primary tumour. In the cN0 group 19 of 58 (32.7%) patients who underwent an END had occult metastases. In clinically positive neck (cN+) patients a Modified Radical Neck Dissection (MRND), at least, must be performed. The criteria to add adjuvant radiotherapy (PORT) include deep lobe parotid tumours, advanced lesions (T3-T4), microscopic (R2) or macroscopic (R1) residual disease after surgery, high grade tumours, perineural diffusion, lymph node metastasis, capsular rupture, and local recurrence after previous surgery. Kaplan-Meier analyses have shown a reduction in the overall survival (OS) from 100% to 91% and in disease-free survival (DFS) from 100% to 95.5% for the NO-PORT and PORT group, respectively. In our study, the cN0 pN+ patients had a higher degree of DFS compared to the cN+.

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.

Preoperative evaluation and treatment consideration of parotid gland tumors

BACKGROUND

The nature of parotid tumors often remains unknown preoperatively and final histopathology may reveal unexpected malignancy. Still, the use of fine-needle aspiration cytology (FNAC) and imaging varies in the management of these tumors.

METHODS

We evaluated the preoperative examinations and management of all 195 parotid gland tumors diagnosed within our catchment area of 1.6 million people during 2015.

RESULTS

Altogether 171 (88%) tumors were classified as true salivary gland neoplasms. FNAC showed no false malignant findings, but it was false benign in 5 (2.6%) cases. Preoperative MRI was utilized in 48 patients (25%). Twenty (10%) malignancies included 16 salivary gland carcinomas. Pleomorphic adenomas accounted for 52% of all adenomas. For 24 (40%) Warthin tumors, surgery was omitted.

CONCLUSION

The proportion of malignancies was lower than generally presented. Our proposed guidelines include ultrasound-guided FNAC with certain limitations. MRI is warranted in selected cases, but seems unnecessary routinely.

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.

Concurrent presence of secretory carcinoma and Warthin's tumor in ipsilateral parotid gland

BACKGROUND

The presence of synchronous benign and malignant salivary gland neoplasms is very rare. The authors present a previously unreported combination of Secretory Carcinoma (SC) and Warthin's Tumor (WT) within the same parotid gland.

METHODS

The patient presented with increasingly painful enlargement of the left parotid gland. CT scan with contrast revealed a heterogeneous solid/cystic mass in the superficial lobe. Fine needle aspiration cytology favored pleomorphic adenoma (PA) and patient underwent superficial parotidectomy without complication.

RESULTS

Final pathology revealed concomitant presence of SC and WT. Stains were positive for S100 and mammaglobin, and FISH revealed the presence of t(12;15) (p13;q25) translocation, resulting in the ETV6-NTRK3 fusion gene.

CONCLUSION

It is important for surgeons and pathologists to note the potential for co-existing benign and malignant pathology within the same salivary gland, as this can have an impact on management and prognosis for patients.

Usefulness of ultrasound and fine needle aspiration cytology of major salivary gland lesions

PURPOSE

To assess the clinical value of ultrasound (US) and fine needle aspiration (FNA) of salivary gland lesions prior to surgery, for preoperative decision-making and long-term follow-up/outcome.

MATERIALS & METHODS

We retrospectively analyzed the medical charts of 98 consecutive patients with major salivary gland lesions who were treated in a single medical from 2008 to 2017. Preoperative US and FNA was performed in all patients. Cytology results were compared with histopathological diagnoses. The correlation between preoperative US findings, cytology and histopathological diagnoses was assessed.

RESULTS

Twenty-three specimens were histopathologically malignant, and 75 were diagnosed as benign. Three false-positive results diagnosed as malignant in cytology had a final histology of sialadenitis, pleomorphic adenoma and Warthin's tumor, respectively. In six cases, cytology yielded false-negative results. The overall accuracy of FNA in distinguishing benign from malignant lesions was 91%. Sensitivity was 70% and specificity 93%. There was no significant correlation between US features and final pathology, but larger size had some correlation with malignancy (p = 0.306). No complications were observed during or after performing FNA.

CONCLUSION

FNA from salivary gland lesions is safe and in many cases can help in preoperative decision making or surgical planning. Hence, the results of FNA cytology should have an integral role in clinical decision-making and management of major salivary gland lesions. False-negative results do occur and therefore should be used only as an adjunctive measure.

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.

Preoperative biopsy in parotid malignancies: Variation in use and impact on surgical margins

OBJECTIVES

Determine rate of preoperative biopsy in parotid malignancies, identify factors associated with its use, and its association with surgical margins.

STUDY DESIGN

Retrospective cohort.

SETTING

Commission on Cancer-Accredited Institutions.

SUBJECTS AND METHODS

We included 5533 patients treated surgically for a parotid malignancy 2004-2014 in the National Cancer Database. Chi-squared tests, univariable, and multivariable logistic regressions were used to evaluate predictors of preoperative biopsy (defined as needle, aspiration, or incisional), and associate biopsy with surgical margins.

RESULTS

Preoperative biopsy was utilized in 26.0% of patients. Biopsy was more likely in patients >60 years (odds ratio [OR]: 1.19, P = .035), advanced clinical T stage (vs. T1,T2 OR: 1.23, P = .009; T3 OR: 1.26, P = .026; T4A OR: 2.05, P < .001), advanced clinical N stage (vs. N0, N1: OR: 1.39, P = .013; N2/3: OR: 1.63, P < .001), in academic centers (OR: 1.18, P < .024), and in higher volume centers (vs. low, medium OR: 1.28, P = .002; high OR: 2.16, P < .001). Biopsy use increased over time (vs. 2004-2006, 2007-2010 OR: 1.20, P = .047; 2011-2014 OR: 1.39, P < .001). Biopsy was associated with a reduced risk of positive margins in patients with clinical T1 stage (OR: 0.70, P = .012), and younger than 61 (OR: 0.79, P = .036).

CONCLUSION

The national rate of preoperative biopsy in parotid malignancy is low at 26.0%, but has increased over time. Preoperative biopsy is associated with a reduced risk of positive margins in younger patients and those with early clinical stage, suggesting its increased use may improve surgical outcomes and decrease reoperation or adjuvant therapy in these subgroups of patients.

LEVEL OF EVIDENCE

3 Laryngoscope, 130:1450-1458, 2020.

Ultrasonographic and elastographic biometry in adult major salivary glands: a preliminary case-control report

Specifications about the size and stiffness of healthy salivary glands with ultrasound (US) are not available for Asian people. Using a Toshiba Apolio 500 US platform, we determined the size (including anterior-posterior median length, median paramandibular depth dimension, and cranio-caudal height) and hardness of 100 healthy submandibular and parotid glands in volunteers without a history of disease affecting the salivary glands or post-radiation, and compared the dimensions to those of 36 parotid glands and 37 submandibular glands in post-irradiated patients. The dimensions of the parotid and submandibular glands were significantly correlated with body weight. However, the dimension of the parotid glands was not significantly correlated with that of patients with prior radiation; the shear wave velocity (SWV) significantly increased (1.99 m/s versus 2.43 m/s, p-value < 0.01). The dimension of the submandibular glands was significantly correlated with prior radiation, where the SWV also significantly increased (2.32 m/s versus 2.50 m/s, p-values < 0.01). We find that US is a useful tool for assessment of the reference dimensions and hardness of major salivary glands that may be altered by irradiation.

Risk of malignancy associated with cytomorphology subtypes in the salivary gland neoplasm of uncertain malignant potential (SUMP) category in the Milan System: A bi-institutional study

BACKGROUND

Salivary gland neoplasm of uncertain malignant potential (SUMP) is a diagnostic category in the Milan System for Reporting Salivary Gland Cytopathology. The objective of this study was to assess the risk of neoplasm (RON) and the risk of malignancy (ROM) in SUMP cases by evaluating them based on their prominent cytomorphology.

METHODS

The pathology databases were searched for cases of fine-needle aspiration-diagnosed SUMP at The Johns Hopkins Hospital and Northwestern University from 2013 to 2018. Only cytopathology cases diagnosed as SUMP that had available surgical follow-up were included.

RESULTS

Sixty-five patients with SUMP were identified, including 31 men and 34 women who ranged in age from 15 to 87 years (mean age, 55.2 years). Sixty-five cases had histologic follow-up, including 13 (20%) with basaloid features, 13 (20%) with oncocytic features, and 39 (60%) with unspecified features. No cases with clear cell features were found. Overall, the RON in the SUMP category was 95.4% (62 of 65 cases), and the ROM was 33.8% (22 of 65 cases). The RON in SUMPs with basaloid, oncocytic, and unspecified subtypes was 92.3%, 100%, and 94.9%, respectively, whereas the ROM was 38.5%, 7.7%, and 41%, respectively. The most common benign neoplasm was pleomorphic adenoma (23.1%), whereas mucoepidermoid carcinoma (9.2%) was the most common malignant neoplasm.

CONCLUSIONS

This study shows that the ROM differs significantly based on cytomorphology subtypes, whereas the overall ROM is approximately the same as the target rate in the Milan System for Reporting Salivary Gland Cytopathology. Moreover, the RON remains high in the SUMP category among different cytomorphology subtypes. Adequate sampling, immunohistochemical staining, and familiarity with metaplastic and reactive changes may improve the diagnosis.

A Call for Universal Acceptance of the Milan System for Reporting Salivary Gland Cytopathology

OBJECTIVES

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) established a standardized, tiered reporting system for salivary gland fine-needle aspiration (FNA) that has gained international acceptance among cytologists. Our goal was to review the key features of the MSRSGC to familiarize the surgical community with this system and its application to the FNA evaluation of salivary gland masses.

METHODS

A comprehensive review of the MSRSGC and its application in clinical practice.

RESULTS

The MSRSGC consists of six major diagnostic categories: 1) nondiagnostic, 2) non-neoplastic, 3) atypia of undetermined significance, 4) neoplasm (benign or salivary gland neoplasm of uncertain malignant potential), 5) suspicious for malignancy, and 6) malignant. Each diagnostic category is associated with an implied risk of malignancy with implications for clinical management.

CONCLUSIONS

The MSRSGC is similar to the system used for reporting thyroid FNA, which is familiar to most otolaryngologists and head and neck surgeons. As this reporting system continues to gain popularity among pathologists, widespread understanding by surgeons will be important to standardize communication and classification of salivary gland cytopathology to improve clinical care. Laryngoscope, 130:80-85, 2020.