Relative accuracy of fine-needle aspiration and frozen section in the diagnosis of lesions of the parotid gland

High Field MRI in Parotid Gland Tumors: A Diagnostic Algorithm

Backgrounds: Imaging of parotid tumors is crucial for surgery planning, but it cannot distinguish malignant from benign lesions with absolute reliability. The aim of the study was to establish a diagnostic MRI algorithm to differentiate parotid tumors. Methods: A retrospective study was conducted including all patients with parotid tumors, who underwent 3T-MRI and surgery. Morphological characteristics and normalized T2 and late postcontrast T1 signal intensities (SI) were assessed. "Ghosting sign" on late postcontrast T1 sequence was defined as indistinguishability of the tumor except for a thin peripheral enhancement. Patients were divided according to histology and imaging data were compared. A diagnostic MRI algorithm was established. Results: Thirty-six patients were included. The combination of normalized late T1 postcontrast SI, normalized T2 SI and "ghosting sign" allowed for the distinguishing of malignant from benign parotid tumors with high sensitivity (100%), specificity (93%), positive predictive value (80%), negative predictive value, (100%) and accuracy (94%). Moreover, pleomorphic adenomas often showed a homogeneous T2 signal and a complete capsule (p < 0.01), Warthin tumors protein-rich cysts and calcifications (p < 0.005 and p < 0.05), and malignant tumors an inhomogeneous contrast enhancement (p < 0.01). Conclusions: High field MRI represents a promising tool in parotid tumors, allowing for an accurate differentiation of malignant and benign lesions.

Diagnostic Values of Fine Needle Aspiration Cytology and Frozen Section in Management of Parotid Tumors

Background: This study aims to investigate the diagnostic values of fine needle aspiration cytology (FNAC) and frozen section (FS) in evaluating parotid gland masses subjected to parotidectomy. Methods: A retrospective analysis of data from 274 patients who underwent parotidectomy for parotid gland masses was performed at the Department of Otolaryngology of the University Hospital between 2013 and 2019. We compared the preoperative FNAC and intraoperative FS records with the definitive histopathological diagnoses obtained from the surgical resection specimens. Results: The sensitivity, specificity, accuracy, positive predictive, and negative predictive value of FNAC in reaching the correct diagnosis were 65.1%, 94.1%, 88.7%, 77.1%, and 92.1%, respectively. The FS analysis values were 92.9%, 97.2%, 95.3%, 96.3%, and 94.6%, respectively. Additionally, the true-positive, true-negative, false-positive, and false-negative cases are documented and discussed. Conclusions: Although FNAC is a commonly used, easy, and reliable diagnostic method for parotid tumors, the diagnostic values observed in our study are low. FS analysis appears to be a more robust method. Therefore, we recommend a balanced use of these diagnostic tools, informed by clinical judgment, patient considerations, and available resources, to optimize outcomes in the management of parotid gland tumors.

Salivary Gland Neoplasm of Uncertain Malignant Potential (SUMP) (Milan IVB) and Its Subgroups: A Multi-Institutional Analysis of Risk of Neoplasm and Malignancy

OBJECTIVES

Fine needle aspiration (FNA) plays a crucial role in their initial assessment of salivary gland neoplasms. In the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC), the category of Salivary Gland Neoplasm of Uncertain Malignant Potential (SUMP) categorizes lesions with ambiguous features. This study aims to investigate the risk of neoplasm (RON) and risk of malignancy (ROM) within different subgroups of SUMP lesions using data from three large academic institutions.

METHODS

We analyzed salivary gland (FNA) cases from three academic institutions post-MSRSGC implementation. Salivary gland FNA cases categorized as Milan IVB (SUMP) with subsequent surgical pathology follow-up were analyzed. Cases were divided into basaloid, oncocytic, and clear cell SUMP subtypes, with RON and ROM assessed and compared.

RESULTS

Out of 1377 MSRSGC cases, 231 were SUMP (16.8%), with 101 subjected to surgical pathology follow-up. The overall ROM for SUMP was 20.8%, with variations of 10% to 29.5% observed amongst institutions, but no significant difference was observed among three institutions (p = 0.15). Basaloid and oncocytic SUMP displayed 17.1% and 20.5% ROM, respectively, without significant disparity. However, all clear cell SUMP cases were malignant on surgical resection.

CONCLUSIONS

This study highlights the variability in ROM for SUMP lesions and the significantly higher ROM in SUMP cases with clear cell features. These findings emphasize the importance of accurately subcategorizing SUMP lesions, particularly those with clear cell features, for appropriate clinical management.

Update on the Treatment of Salivary Gland Carcinomas

Salivary gland carcinoma is a rare form of head and neck carcinoma, but it comprises a variety of subsites and histologic subtypes that each present with unique clinical courses and management challenges. Preoperative work-up generally consists of fine-needle aspiration cytology and MRI. However, because of the large variety of subtypes, there are often challenges obtaining a histologic diagnosis before surgery. Upfront surgery at the primary site leads to the greatest improvement in survival. Posttreatment surveillance of these patients is important. This article discusses some of the current controversies in the management of salivary gland carcinomas.

Application of the Milan System of reporting salivary gland cytopathology and assessing its use as a risk stratification tool

INTRODUCTION

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was proposed by American Society of Cytopathology and International Academy of Cytology to standardize reporting system ensuring uniformity and better communication between clinicians and cytopathologists.

AIMS AND OBJECTIVES

1. To categorize salivary lesions as per MSRSGC. 2. To establish diagnostic accuracy of MSRSGC and calculate risk of malignancy for each diagnostic category.

MATERIALS AND METHODS

An ambispective study was conducted over 5 years including 45 FNAC cases of salivary lesions. The cases were categorized according to Milan System, and diagnostic accuracy of MSRSGC was established. Risk of malignancy for each category was calculated.

RESULTS

The patients' age ranged from 13 to 77 years with maximum swellings in parotid (53.3%) followed by submandibular (15.6%) and submental (2.2%). Histopathological follow-up was done in all cases. The number of cases in each category was as follows: category I: 03 (6.7%), category II: 06 (13.3%), category III: 4 (8.9%), category IVA: 25 (55.6%), category IVB: 04 (8.9%), category V: 02 (4.4%), and category VI: 01 (2.2%). The calculated ROM was as follows: category I: 0%, category II: 0%, category III: 0% category IVA: 8.0%, category IVB: 25%, category V: 50%, and category VI: 100%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy with (without) indeterminate categories for malignancy were 88.9%(96.9), 66.7%(50.0), 94.1%(94.1), 50.0%(66.7), and 85.7%(91.9), respectively.

CONCLUSION

MSRSGC is an effective and standardized reporting system for categorization and risk stratification of salivary swellings which helps in enhancing patient care.

Correlation between MRI (DWI and DCE) and cellularity of parotid gland pleomorphic adenomas

PURPOSE

Parotid pleomorphic adenomas present a risk of recurrence, higher when the tumour is a hypocellular subtype. The aim of the study was to determine whether it is possible to characterize this histological subtype with diffusion and perfusion sequences of the preoperative MRI.

METHODS

This retrospective study included 97 patients operated between 2010 and 2020. Histologic slides review was performed to classify tumours into three histologic subtypes: hypocellular, classical and hypercellular. Univariate and multivariate analyses studied the correlation between histology and diffusion and perfusion MRI parameters obtained with OleaSphere® software.

RESULTS

The hypocellular subtype had higher apparent diffusion coefficient values than the other two subtypes: 2.13 ± 0.23, 1.83 ± 0.42, and 1.61 ± 0.4 × 10-3 mm2/s for hypocellular, classical and hypercellular subtype respectively (p < 0.0001). Multivariate analysis showed that an ADCmean > 1.88 × 10-3 mm2/s was suggestive of a hypocellular pleomorphic adenoma in 79% of the cases, with a specificity and PPV of 94 and 96% (p < 0.001), respectively.

CONCLUSION

The histological subtype of a pleomorphic adenoma can be predicted preoperatively with ADC values. A prospective and multicentric study on a larger cohort is needed to confirm our results.

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.

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

INTRODUCTION

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

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

The evolving landscape of salivary gland tumors

Salivary gland cancers are a rare, histologically diverse group of tumors. They range from indolent to aggressive and can cause significant morbidity and mortality. Surgical resection remains the mainstay of treatment, but radiation and systemic therapy are also critical parts of the care paradigm. Given the rarity and heterogeneity of these cancers, they are best managed in a multidisciplinary program. In this review, the authors highlight standards of care as well as exciting new research for salivary gland cancers that will strive for better patient outcomes.

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.

Keloid masking a parotid tumor: A rare case presentation

A 37-year-old Nigerian woman presented with an itchy and occasionally painful scar that appeared after the healing of an acne lesion over the left parotid region, 13 years ago. She noticed a progressive increase; however, there was no history of facial weakness. Examination revealed a keloid lesion overlying a firm nontender mass. Ultrasound scan and fine-needle aspiration cytology indicated a benign tumor of the left parotid. Superficial parotidectomy was performed, and the histology revealed a keloid overlying a pleomorphic adenoma. This is an unusual presentation of keloid which developed over a pleomorphic adenoma. Hence, we report the above case for its rarity.

The Milan System for Reporting Salivary Gland Cytopathology

OBJECTIVES

Our study assesses whether the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) offers any benefit over the original cytology classification, and measures interobserver agreement.

METHODS

Four cytopathologists retrospectively blindly classified preoperative cytology by MSRSGC from 101 resected salivary tumors. Consensus MSRSGC diagnoses were correlated with surgical pathology diagnoses and compared with the original cytology classification. Diagnostic parameters were calculated for both systems. Interobserver variability was assessed.

RESULTS

The original cytology classification vs MSRSGC had sensitivity, specificity, positive predictive value, and negative predictive value of 75.0% vs 78.3%, 97.1% vs 98.0%, 91.2% vs 94.7%, and 90.1% vs 90.0%, respectively. The original cytology classification risk of neoplasm (RON) was 91.7% for "negative for malignancy" and 100.0% for other categories. The MSRSGC RON was 71.4% in category II (nonneoplastic) and 100.0% in all other categories. The original cytology classification risk of malignancy (ROM) ranged from 0.0% for "atypical" to 100.0% for "positive for malignancy." The MSRSGC ROM ranged from 0.0% in categories I (nondiagnostic) and III (nonneoplastic) to 100.0% in category VI (malignant). Weighted agreement using the MSRSGC was 92% (Gwet AC1, 0.84); unweighted agreement was 69% (Gwet AC1, 0.64). MSRSGC category IVA (benign neoplasm) was most likely to show interobserver agreement, with complete agreement in 67% of cases.

CONCLUSIONS

The MSRSGC performs similarly to the original cytology classification and shows relatively high interobserver agreement.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Frozen Section of Parotid Gland Tumours: The Head and Neck Pathologist as a Key Member of the Surgical Team

Introduction: The aim of this study was to evaluate the impact of subspecialised head and neck versus general surgical pathologists on the reliability of the histopathologic evaluation during intraoperative consultation. Materials and Methods: The medical records of all patients who underwent a parotidectomy with frozen section between 2006 and 2021 were retrospectively evaluated. The frozen section was evaluated for sensitivity, specificity, accuracy, and predictive value. Assessment by two groups of pathologists (subspecialised head and neck versus general surgical pathologists) was compared, and the nature or types of misdiagnoses compared with final diagnoses on paraffin sections were analysed for the two groups. Results: Our study sample was made up of 669 cases. The mean age of patients was 57.7 years (range: 10−94 years). Of these, 490 patients had a benign lesion (73.2%), whereas 179 patients had a malignant lesion (26.8%). Frozen section had an overall accuracy of 97.6%, sensitivity for malignancy was 91.1%, specificity was 100%, PPV was 100%, and the NPV was 96.8%. The exact histologic subtype in the group of malignant tumours was correctly identified in FS in 89.4% of cases. A comparison of head and neck pathologists versus general surgical pathologists revealed a highly statistically significant difference concerning both overall detection of malignancy (p < 0.001) as well as correct identification of the histologic subtype (p < 0.001). Conclusion: Involvement of subspecialised head and neck pathologists in the intraoperative consultation for salivary gland tumours results in a gain of 19.8% more sensitivity, underlining the importance of specialisation in salivary gland pathology for the optimisation of frozen section quality.

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

Introduction:

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

Aims:

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

Settings and Design:

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

Methods and Materials:

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

Results:

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

Conclusions:

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

Diagnostic accuracy of ultrasonography-guided core needle biopsy of parotid gland neoplasms: A large, single-institution experience in United Kingdom

Salivary gland tumours present a pleomorphic and complex morphology and, apart from the most common neoplasms with well-established histopathological criteria, may create diagnostic difficulty for histopathologists. The majority of salivary gland tumours occur in the parotid gland and the use of ultrasound guided parotid biopsy (US-PB) has increased. US-PB in contrast with fine needle aspiration (FNA), which is an easy and relatively painless technique, is performed under local anaesthesia, usually by radiologists. US-PB offers some advantages over the FNA such as tumour grading and the possibility of performing immunohistochemistry. We report our experience of the diagnostic value of US-PB in a large, referral centre in the United Kingdom.

Pilot study on the value of Raman spectroscopy in the entity assignment of salivary gland tumors

Background

The entity assignment of salivary gland tumors (SGT) based on histomorphology can be challenging. Raman spectroscopy has been applied to analyze differences in the molecular composition of tissues. The aim of this study was to evaluate the suitability of RS for entity assignment in SGT.

Methods

Raman data were collected in deparaffinized sections of pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC). Multivariate data and chemometric analysis were completed using the Unscrambler software.

Results

The Raman spectra detected in ACC samples were mostly assigned to nucleic acids, lipids, and amides. In a principal component-based linear discriminant analysis (LDA) 18 of 20 tumor samples were classified correctly.

Conclusion

In this proof of concept study, we show that a reliable SGT diagnosis based on LDA algorithm appears possible, despite variations in the entity-specific mean spectra. However, a standardized workflow for tissue sample preparation, measurement setup, and chemometric algorithms is essential to get reliable 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.

Risk stratification of parotid neoplasms based on intraoperative frozen section and preoperative fine needle aspiration cytology

PURPOSE

This study aims to determine the relationship of frozen section (FS) to final histology and determine how incorporating FS may change preoperative malignancy risk estimates based on preoperative fine needle aspiration cytology (FNAC). The secondary aim is to determine if FS is useful in influencing intraoperative decision-making.

METHODS

Retrospective review of 426 intraoperative FS for parotidectomies performed for primary parotid lesions.

RESULTS

Risk of malignancy with a benign FS was 2.5%, with indeterminate 36.1%, and with malignant 100%. Incorporating FS to fine needle aspiration for cytology helped to stratify malignancy risk especially in the Milan categories of atypia of undetermined significance, neoplasm of uncertain malignant potential and non-diagnostic categories, where a malignant FS increased malignancy risk significantly. FS was only able to identify 11% of high-risk histological subtypes for which a neck dissection would be recommended.

CONCLUSIONS

FS may be used to stratify malignancy risk intraoperatively but has limited utility in clinical decision-making to perform a neck dissection and more extensive parotid resection in high-risk histological subtypes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Objectives:

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

Material and Methods:

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

Results:

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

Conclusion:

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

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

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

METHODS

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

RESULTS

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

RECOMMENDATIONS

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

Utility of ultrasound-guided fine needle aspiration cytology in assessing malignancy in head and neck pathology

OBJECTIVE

Fine needle aspiration cytology (FNAC) is a well-established diagnostic procedure for head and neck masses not clearly originating from mucosal or cutaneous surfaces. We analysed head and neck masses evaluated over a 2-year period, to assess the reliability of FNAC for the evaluation of malignancy.

METHODS

We enrolled all patients undergoing FNAC, from April 2013 to July 2015, in a single service of a large Italian university hospital. Relevant clinical data and ultrasonographic parameters of the lesions were recorded. We performed both conventional and thin-prep smears. Clinical presentation, ultrasonographic features and final cytology diagnoses were analysed and correlated with histology.

RESULTS

The series included 301 lesions in 285 patients, with a single (94.4%) or two (5.6%) lesions. Only eight samples were considered non-diagnostic/inadequate (2.6%). Among the cases, 139 FNAC (46.1%) underwent surgery. Cytological-histological correspondence was found in 89% of the cases. Concerning malignancy, we documented less than 4% false positives and less than 2.5% false negatives, with 92.7% sensitivity and 94.6% specificity.

CONCLUSION

FNAC diagnosis can be highly specific. Most importantly, it is highly reliable in assessing malignancy, thus defining the priority and guiding the management procedures.

Narrative review of multiparametric ultrasound in parotid gland evaluation

Disorders affecting parotid gland represent a heterogeneous group comprising congenital, inflammatory and neoplastic diseases which show a focal or diffuse pattern of appearance. The differentiation of neoplastic from non-neoplastic conditions of parotid glands is pivotal for the diagnostic imaging. Frequently there is evidence of overlapping between the clinical and the imaging appearance of the various pathologies. The parotid gland is also often object of study with the combination of different techniques [ultrasound-computed tomography-magnetic resonance imaging (US-CT-MRI), ex.]. Compared to other dominant methods of medical imaging, US has several advantages providing images in real-time at lower cost, and without harmful use of ionizing radiation and of contrast enhancement. B-mode US, and the microvascular pattern color Doppler are usually used as first step evaluation of parotid lesions. Elastography and contrast-enhanced US (CEUS) has opened further possible perspectives to improve the differentiation between benign and malignant parotid lesions. The characterization of the parotid tumors plays a crucial role for their treatment planning and for the prediction of possible surgical complications. We present, here an updated review of the most recurrent pathologies of parotid gland focusing on the diagnostic power of multiparametric US including CEUS and ultrasound elastography (USE); limitations, advantages and the main key-points will be presented.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

[Correlation between magnetic resonance imaging and extemporaneous and definitive histological examination of parotid gland tumors: a case series]

Parotid gland tumor is complex and poses diagnostic and therapeutic problems. The purpose of this study was to assess the role of extemporaneous examination in the management of patients with parotid gland tumors. We report a pro and retrospective analytical study of a series of cases of salivary gland tumors, whose data were collected in the ENT and in the department of cervical-facial Surgery at the University Hospital in Casablanca, between January 2012 and December 2015. Seventy two cases of parotid tumors were recorded. The sex-ratio (H/F) was 0.94, 0.76 for patients with benign tumors and 1.62 for patients with malignant tumors. The average age was 47 years (15- 75 years). The median of consultation time was 40 months. Clinical symptoms were dominated by parotid swelling (100%), pain in 25% of patients, facial palsy in 6%, and cervical adenopathies in 10%. Ultrasound was recommended in 80% of patients. MRI was performed in 26% of cases. All patients underwent surgery, 76% of patients underwent exofacial parotidectomies and 24% total conservative parotidectomies. This treatment was associated with ganglion resection in 24% of cases and radiotherapy in 24% of cases. Extemporaneous examination was performed in 71% of patients, its susceptibility was 89% and its specificity 88%. Definitive histological diagnosis was confirmed by anatomopathological examination in all cases. We confirmed benign and malignant tumors in 71% and 29% of cases respectively. Benign tumors were dominated by pleomorphic adenoma (59%), while malignant lesions were dominated by mucoepidermoid carcinoma (38%). The postoperative course was marked by: discrete haematoma in 4% of cases, transient facial palsy in 15%, superinfection of the wound in 3% and post-parotidectomy Frey´s syndrome in 3% of patients. One patient had labial recurrence of acinar cell carcinoma. No cases of death were noted. Parotid gland tumors are characterized by a great histological variability. Differentiation between malignant tumor and benign tumor is often difficult. Currently, MRI is the imaging test of choice. Extemporaneous examinationis is very useful intraoperatively when it is necessary to communicate with the pathologist. Multidisciplinary approach is adopted including ENT, oncological, radiotherapeutic, pathological and radiological approaches. Prognosis depends on the histological type, the stage of progression and treatment.

Basal cell adenocarcinoma of the parotid gland: Comparison with basal cell adenoma for preoperative diagnosis

OBJECTIVE

To summarize the diagnosis and treatment outcomes of basal cell adenocarcinoma (BCAC) of the parotid gland, a rare low-grade malignancy, at a single institution, and to investigate the treatment approach for this rare malignancy.

METHODS

We conducted a retrospective analysis of 9 patients with BCAC during 20 years from September 1999 to December 2019. Forty-five patients with basal cell adenoma (BCA), who were treated during the same time period, were used for comparison. The clinical characteristics of BCAC, diagnostic imaging, the usefulness of fine-needle aspiration cytology (FNAC) and frozen section biopsy (FSB), histological assessment of malignancy, and treatment outcomes were investigated.

RESULTS

There were no marked differences in sex, age, tumor diameter, or tumor location between BCAC and BCA cases. Among the 9 patients with BCAC, one patient was noted with pain/tenderness, and two patients were observed with adhesion to the surrounding tissues. Only one patient was diagnosed as malignant based on MRI/US. FNAC for BCAC was suspicious for malignancy in 6 of the 9 cases, which included one patient with the correct grade of malignancy, one patient with malignancy only, and 4 patients suspicious for malignancy. FSB was suspicious for malignancy in 8 of the 9 cases. Malignancy grade was determined based on infiltration to the surrounding tissues and expression of Ki-67, p53, and bcl-2. One patient with infiltration to the surrounding tissue was diagnosed as intermediate-grade malignancy, while the remaining 8 patients were diagnosed as low-grade malignancy. The BCAC cases included 7 patients with T2 and 2 patients with T1. Conservative resection was performed for all patients, and all cases are surviving cancer-free.

CONCLUSION

The malignancy of BCAC can be suspected before surgery based on symptoms/signs, diagnostic imaging, and FNAC. FSB enables the diagnosis of not only malignancy but also the grade of malignancy, which may help determine the appropriate surgical resection. Although all 9 patients with BCAC are surviving free from cancer, a long-term follow-up is warranted.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Conventional and Diffusion-Weighted MR Imaging Findings of Parotid Gland Tumors

OBJECTIVE

To investigate diffusion-weighted magnetic resonance imaging (MRI) findings of parotid gland lesions in addition to conventional MRI findings and demographic data.

METHODS

A retrospective evaluation was made of the demographic data, histopathologic data, preoperative conventional and diffusion-weighted MRI of 74 patients who underwent parotidectomy. The patients were categorized according to the histopathology (pleomorphic adenoma [PA], Warthin's Tumor [WT] and malignant Tumor [MT]).

RESULTS

Histologically, 30 patients had PA, 27 patients had WT, and the remaining 17 patients had MT. The mean age of the PA, WT and MT groups were 44±21 (20-72), 55±10 (41-71) and 62±20 (21-76) years, respectively. The WT (81%) and MT (70%) groups were male dominant, while the PA group showed female dominance (55%). The PA group showed statistically significant difference in terms of age (p<0.05) and gender (p=0.009) compared to the other two groups. The median apparent diffusion coefficient (ADC) values for the PA, WT and MT groups were 1.99±0.94 (1.10-2.41) × 10-3 mm2/s, 0.92±0.35 (0.21-1.79) × 10-3 mm2/s and 1.20±0.34 (0.78-1.47) × 10-3 mm2/s, respectively. PA was differentiated from the other two groups (p=0.001). The sensitivity and specificity for distinguishing PAs from WT was 97% and 85%, respectively, when the ADC cutoff value was 1.25; and for distinguishing PAs from MT was 77% and 83%, respectively, when the ADC cutoff value was 1.35.

CONCLUSION

ADC measurements are useful for the differentiation of PA from both WT and MT; and can be used as a complementary tool to predict the histopathology in the preoperative planning of parotid tumors.

Differentiation of salivary gland tumors through tumor heterogeneity: a comparison between pleomorphic adenoma and Warthin tumor using CT texture analysis

PURPOSE

We compared the diagnostic performance of CT texture analysis in single-phase CT scan with that of conventional enhancement pattern analysis in a two-phase CT scan for discrimination of salivary gland tumors, Warthin tumor (WT) from pleomorphic adenoma (PA).

METHODS

One hundred seventy-eight patients with PA and 84 patients with WT were selected and CT texture analysis was separately performed on early (40s) and delayed (180s) phases, after injection of the contrast agent, using commercially available software. The attenuation changes and enhancement patterns were visually and quantitatively assessed with Hounsfield units (HU). Differences between PAs and WTs were analyzed using χ² test and independent t test. Diagnostic performance of texture parameters in single-phase CT was compared with that of dynamic enhancement pattern in two-phase CT using the McNemar test.

RESULTS

Ratio of tumoral HU (delayed phase/early phase) was significantly higher in PAs compared with WTs (p < 0.001). Tumor heterogeneity parameters, standard deviation (SD) and entropy, were significantly lower in WTs regardless of the type of filter used (p ≤ 0.001). Mean with coarse filter (AUC = 0.944) on early phase scan and entropy with medium filter (AUC = 0.901) on delayed scan were best discriminators between PAs and WTs. Diagnostic accuracy of mean (90.5%) on early scan and entropy (84.7%) on delayed scan was not significantly different from the accuracy (89.3%) of conventional wash-out pattern for distinguishing WTs from PAs (p = 0.742, p = 0.088, respectively).

CONCLUSION

Diagnostic performance of texture parameters was similar to that of quantitative enhancement pattern for differentiating WTs from PAs, with the advantage in lower radiation exposure.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Salivary gland fine-needle aspiration cytology with the application of the Milan system for risk stratification and histological correlation: A retrospective 6-year study

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is based on risk stratification. We presented our experience with fine-needle aspiration cytology (FNAC) for the diagnosis of salivary glands lesions by applying the MSRSGC categorization to the cytological diagnoses, and determined risk of malignancy (ROM) for each category.

METHODS

Fine-needle aspiration cytology of salivary gland lesions performed over a 6-year period was retrieved. FNAC results were retrospectively categorized according to the MSRSGC criteria, and correlated with corresponding histologic follow-up. ROM for each diagnostic category was calculated.

RESULTS

A total of 208 FNAC of salivary gland lesions were reviewed and retrospectively categorized as: non-diagnostic (ND) 23 (11%), non-neoplastic (NN) 54 (26%), atypia of undetermined significance (AUS) 10 (4.8%), benign neoplasms (BN) 77 (37%), salivary gland of uncertain malignant potential (SUMP) 13 (6.3%), suspicious for malignancy (SM) 7 (3.4%), and malignant (M) 24 (11.5%). Histopathological follow-up was available for 84 of 208 cases (40.4%). Overall concordance rate between FNAC and histology was 78.8%. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated as 93.3%, 94.6%, 82.4%, and 98.2%, respectively. Diagnostic accuracy to distinguish benign from malignant disease was 94.4%. ROM for each category was ND 0%, NN 0%, AUS 75%, BN 2.2%, SUMP 28.6%, SM 50%, and M 100%.

CONCLUSION

Fine-needle aspiration cytology continues to be an accurate diagnostic tool for most salivary gland neoplasms showing classical morphologic features. However, difficult cases with unusual or overlapping features will occur. In these situations, the use of MSRSGC risk-stratification could be helpful to define appropriate management.

Multiparametric ultrasound evaluation of parotid gland tumors: B-mode and color Doppler in comparison and in combination with contrast-enhanced ultrasound and elastography. A case report of a misleading diagnosis

Preoperative characterization of parotid gland tumors using imaging or cytological examination (fine-needle aspiration cytology) has a strong clinical and therapeutic impact, but it is often difficult due to the tumors' histological heterogeneity. The recent introduction of contrast-enhanced ultrasound (CEUS) and elastography, in the context of multiparametric ultrasound evaluation, contributed to improving the preoperative diagnosis of many diseases affecting the liver, breast, and thyroid, as well as other organs. However, limited evidence is available on the use and the diagnostic power of these techniques in parotid gland neoplasms. In this paper, we present a case of a parotid lesion that highlights the importance of a complete workup using multiparametric ultrasound evaluation, including CEUS and elastography, to identify malignant tumors of the parotid gland.

Characterization of parotid gland tumors using T2 mapping imaging: initial findings

Background

Preoperative accurate characterization of parotid gland tumors in different histologic types is crucial. T2 mapping has been proven to be useful for improving the accuracy of tumor characterization.

Purpose

To evaluate the ability of T2 mapping imaging in the characterization of parotid gland tumors.

Material and Methods

T2 mapping imaging was scanned in 74 patients (56 benign, 18 malignant) with pathologically confirmed parotid gland tumors. Mean T2 relaxation time was calculated and compared between benign and malignant group, and among malignant tumors, Warthin’s tumors, and pleomorphic adenomas. Independent-samples t test, one-way analysis of variance test, and receiver operating characteristic curve analyses were used for statistical analyses.

Results

The malignant group showed significantly lower T2 relaxation times than the benign group ( P = 0.001). Using a relaxation time of 91.5 ms as the cut-off value, optimal diagnostic performance could be achieved (area under the curve [AUC] 0.679, sensitivity 46.4%, specificity 94.4%). Pleomorphic adenomas showed significantly higher T2 relaxation times than malignant tumors ( P = 0.003) and Warthin’s tumors ( P = 0.001). However, no significant difference was found on the T2 relaxation times between Warthin’s tumors and malignant tumors ( P = 0.435). Optimal diagnostic performance could be achieved (AUC 0.783, sensitivity 58.1%, specificity 94.4%), when setting a T2 value of 92.0 ms as the threshold value for differentiating pleomorphic adenomas from malignant tumors. Meanwhile, optimal AUC, sensitivity, and specificity were 0.892, 87.1%, and 83.3%, respectively, when setting a T2 value of 80.5 ms as the threshold value for differentiating pleomorphic adenomas from Warthin’s tumors.

Conclusion

T2 mapping imaging could serve as an incremental imaging biomarker for characterizing parotid gland tumors.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Introduction:

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

Methods and Material:

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

Results:

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

Conclusions:

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

Discordance between fine-needle aspiration cytology and histopathology in patients with mucoepidermoid carcinoma of parotid gland

INTRODUCTION

Fine-needle aspiration cytology (FNAC) is an important diagnostic tool used preoperatively for the diagnosis of parotid lump. Mucoepidermoid carcinoma comprises 5-10% of all salivary gland tumours. It poses a diagnostic challenge on FNAC with high false negative rate. The objective of this study was to evaluate the discordance between cytology/FNAC and histopathology in patients with mucoepidermoid carcinoma.

MATERIAL AND METHODS

A cross-sectional study was conducted from 1 January 2010 to 31 December 2014. Patients aged 18 years and above with FNAC or histopathology suggestive of mucoepidermoid carcinoma were identified. FNAC when compared with histology (gold standard) was classified into true positive (presence of mucoepidermoid carcinoma correctly diagnosed on FNAC), true negative (absence of mucoepidermoid carcinoma correctly diagnosed on FNAC), false positive (FNAC incorrectly diagnosed mucoepidermoid carcinoma), false negative (FNAC failed to diagnose mucoepidermoid carcinoma).

RESULTS

A total of 16 patients fulfilled our eligibility criteria. Seven cytological samples were true positive (ie correctly diagnosed mucoepidermoid carcinoma by FNAC), eight cytological specimens were false negative (ie could not pick up mucoepidermoid carcinoma on FNAC). One case was false positive on cytology (ie diagnosed mucoepidermoid carcinoma on FNAC but was reported to be Warthin's tumour on histopathology) and none were true negative.

CONCLUSION

FNAC is not reliable for diagnosis of mucoepidermoid carcinoma. More than 50% of our patients had discordant results between cytology and histology. We recommend a high index of suspicion for mucoepidermoid carcinoma given the poor yield of cytology.

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.

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.

Apparent diffusion coefficient (ADC) histogram analysis: differentiation of benign from malignant parotid gland tumors using readout-segmented diffusion-weighted imaging

OBJECTIVES

To explore the utility of whole-lesion apparent diffusion coefficient (ADC) histogram analysis for differentiating parotid gland tumors following readout-segmented diffusion-weighted imaging (RESOLVE).

METHODS

80 patients (40 with pleomorphic adenomas, 14 with Warthin tumors, and 26 with malignant parotid gland tumors) who underwent routine head-and-neck MRI and RESOLVE examinations, were retrospectively evaluated. RESOLVE data were acquired from a MAGNETOM Skyra 3T MR system. Eleven whole-lesion histogram parameters derived from histogram analysis (ADC_mean, ADC_minimum, ADC_maximum, ADC_1th, ADC_10th, ADC_50th, ADC_90th, ADC_99th, skewness, variance and kurtosis) were calculated for each patient using MaZda. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of the ADC for distinguishing among the three groups.

RESULTS

In total, nine parameters (ADC_minimum, ADC_maximum, ADC_mean, ADC_10th, ADC_50th, ADC_90th, ADC_99th, variance, skewness) were statistically significant (all p < 0.05) for all three groups, in the comparison of pleomorphic adenomas to Warthin tumors; the ADC_mean, ADC_50th, and skewness revealed high diagnostic efficiency with areas under the receiver operating characteristic curve of 0.976, 0.970, and 0.970, respectively. In the comparison of pleomorphic adenomas to malignant parotid gland tumors, these nine parameters were also found to be statistically different (all p < 0.05); the ADC_mean, ADC_10th and ADC_50th revealed high diagnostic efficiency with area under the curve of 0.851, 0.866, and 0.841, respectively. However, in the comparison of Warthin tumors to malignant parotid gland tumors, only three parameters (ADC_mean, ADC_50th, skewness) were statistically significant (all p < 0.05).

CONCLUSIONS

Whole-lesion ADC histograms are effective in differentiating common parotid gland tumors.

Sensitivity of Fine-Needle Aspiration and Imaging Modalities in the Diagnosis of Low-Grade Mucoepidermoid Carcinoma of the Parotid Gland

OBJECTIVE

To determine the diagnostic accuracy of fine-needle aspiration (FNA) and imaging modalities for low-grade mucoepidermoid carcinoma (MEC) of the parotid gland.

METHODS

Retrospective chart review of patients diagnosed with low-grade MEC of the parotid gland following surgical excision between January 2010 and June 2018. Imaging from patients with MEC were randomly mixed with imaging from patients with benign pathology and reviewed in a blinded fashion. Main outcome measure was sensitivity.

RESULTS

A total of 24 patients were confirmed to have had low-grade MEC on final pathology, with a total of 31 FNAs performed between them. Twelve of 31 FNAs were positive for low-grade MEC, with a sensitivity of 39%. A total of 27 imaging studies were reviewed, which included 16 patients with low-grade MEC and 11 patients with benign pathology. Of these 27 imaging studies, 10 were declared indeterminate. Of the remaining 17 imaging studies, 13 were reviewed as malignant (11 true positive and 2 false positive) and 4 as benign (4 true negative). Overall magnetic resonance imaging (MRI) sensitivity for low-grade MEC was 100% (9/9) with 95% CI (0.66-1.0) when considering indeterminate results as positive for malignancy.

CONCLUSION

This study reaffirms that for low-grade MEC, sensitivity of FNA is poor. MRI provides an important diagnostic tool in the evaluation of salivary gland neoplasms, due to its increased sensitivity for low-grade MEC when considering indeterminate results as positive. This provides confidence in the diagnosis of benign tumors and allows appropriate counseling of all options to the patient, including observation. Imaging and low threshold of excision should be considered despite an inflammatory or benign FNA.

Diagnostic Accuracy of Multiparametric Magnetic Resonance Imaging for Differentiation Between Parotid Neoplasms

PURPOSE

This study was designed to evaluate the role of multiparametric magnetic resonance imaging (MRI) for differentiation of parotid gland neoplasms.

METHODS

Prospective study was conducted upon 52 consecutive patients (30 men, 22 women; aged 24-78 years; mean, 51 years) with parotid tumours that underwent multiparametric MRI using combined static MRI, dynamic contrast enhanced (DCE) MRI, and diffusion-weighted imaging (DWI). The static MRI parameter, time signal intensity curves (TIC) derived from DCE-MRI, and apparent diffusion coefficient (ADC) values of parotid tumours were correlated with histopathological findings.

RESULTS

Static MRI revealed a significant difference between both benign and malignant lesions in regards to margin definition (P < .001) and T2 hypointensity (P < .013), with a diagnostic accuracy 95% and 78.33% respectively. Study of the TIC type on DCE-MRI revealed statistically significant difference between benign and malignant lesions (P < .001) and diagnostic accuracy 96.55%. There was no statistically significant difference (P = .181) between the ADC values of benign and malignant lesions. ROC curve analysis revealed that by using ADC cut-off value of 1 × 10^-3 mm²/s had accuracy of 84.62% respectively for differentiating Warthin from malignant tumours that could be modified to higher value (94.28%) by excluding lymphoma from malignant lesions. By using cutoff value of 1.3 × 10^-3 mm²/s to differentiate pleomorphic adenoma from malignancy, ROC curve analysis had high accuracy of 97.06%.

CONCLUSION

Multiparametric MRI can be used for differentiation of malignant from benign parotid tumours and characterization of some benign parotid tumours.

The role of frozen section biopsy for parotid gland tumour with benign fine-needle aspiration cytology

Objectives

This study focused on parotid gland tumours diagnosed as benign by fine-needle aspiration cytology and investigated the necessity of frozen section biopsy.

Methods

There were 104 cases of parotid gland tumour where fine-needle aspiration cytology was benign and frozen section biopsy was subsequently performed, between April 2006 and June 2016. In this retrospective study, the results of frozen section biopsy were analysed and compared with the final histological diagnosis.

Results

Among the 104 cases diagnosed as benign by fine-needle aspiration cytology, 102 cases and 2 cases were diagnosed as benign and malignant, respectively, by frozen section biopsy. The final histological diagnoses showed that 98 cases were benign and 6 cases were malignant. The sensitivity and specificity values of frozen section biopsy in detecting malignant tumours were 33 per cent and 100 per cent, respectively.

Conclusion

The necessity of frozen section biopsy in cases with benign fine-needle aspiration cytology may be low in parotid gland surgery.

A critical appraisal of the Milan system for reporting salivary gland cytology (MSRSGC) with histological correlation over a 3-year period: Indian scenario

BACKGROUND

Fine needle aspiration cytology (FNAC) is the first line investigation for pre-operative diagnosis of salivary gland lesions, but due to its inherent limitations remains a challenge for the cytopathologists. The recently proposed international risk stratification scheme, the Milan System for Reporting Salivary Gland Cytology (MSRSGC) aims to promote and standardise the communication between cytopathologist and clinician thereby improving patient care.

METHODS

A retrospective study of all salivary gland cytology cases was performed over a 3-year period, reviewed by pathologists and categorised into 1 of the 6 diagnostic categories according to MSRSGC, namely, non-diagnostic, non-neoplastic, atypia of undetermined significance (AUS), benign neoplasm, and salivary gland neoplasm of undetermined significance (SUMP), suspicious for malignancy (SFM), and malignant neoplasm. Cyto- histological correlation was done wherever possible. Risk of malignancy (ROM) was calculated for each diagnostic category.

RESULTS

Out of a total of 150 salivary FNAC cases, histopathology was available for 64 cases. The sensitivity of FNAC was 81.8%, specificity was 100% while the diagnostic accuracy was 96.9%. The positive and negative predictive values were 100% and 96.4% respectively. The ROM for non-diagnostic, non-neoplastic, AUS, benign neoplasm, SUMP, SFM, and malignant categories were 0%, 10%, 50%, 2.5%, 50%, 100%, and 100% respectively.

CONCLUSION

MSRSGC fulfils the critical need for a uniform, internationally acceptable reporting system with ROM specified for each category. However, large scale multi centre studies need to be conducted before its reliability and validity is proven.

Quantitative diffusion magnetic resonance imaging in head and neck tumors

In patients with head and neck cancer, conventional anatomical magnetic resonance imaging (MRI) scans are commonly used for identification of primary lesion, assessment of structural distortion, and presence of metastatic lymph nodes. However, quantitative analysis of diffusion MRI can provide added value to structural and anatomical evaluation of head and neck tumors (HNT), by differentiation of primary malignant process, prognostic prediction, and treatment monitoring. In this article, we will review the applications of quantitative diffusion MRI in identification of primary malignant tissue, differentiation of tumor pathology, prediction of molecular phenotype, monitoring of treatment response, and evaluation of posttreatment changes in patient with HNT.

Moving Toward a Systematic Approach for Reporting Salivary Gland Cytopathology: An Institutional Experience and Literature Review

Context.—

Despite the clinical utility of fine-needle aspiration for the diagnosis of salivary pathologies, salivary lesions remain one of the most challenging areas in cytopathology. This is partially because there is no consensus on how to report salivary gland cytopathology, which has resulted in inconsistent terminology among institutions and individual cytopathologists and in confusion in communication among cytopathologists and ordering providers.

Objective.—

To summarize our experience with an institutional salivary gland cytopathology reporting system, as an initiative to promote collaborative work toward a consensus on a reporting system.

Design.—

We developed an empirical 6-tier classification reporting system. Slides of 107 salivary gland fine-needle aspirations with subsequent histology slides were reviewed and reclassified using the 6-tier system. The performance of the cytology reporting system was evaluated with the histology diagnoses serving as the gold standard.

Results.—

Fine-needle aspiration diagnoses made based on the institutional 6-tier classification system were generally consistent with histology diagnoses for the disease spectrum reported in this study. The sensitivity, specificity, positive predictive value, and negative predictive value for diagnosing malignancies with the system were 86% (12 of 14), 93% (40 of 43), 80% (12 of 15), and 95% (40 of 42), respectively. The risk of malignancy increased from 0% (0 of 13) for negative for neoplasm to 7% (2 of 29) for benign neoplasm, 67% (2 of 3) for suspicious for malignancy, and 83% (10 of 12) for positive for malignancy.

Conclusions.—

The institutional 6-tier system provides a succinct, risk-of-malignancy–based system to report salivary gland cytology. Our experience with this system helps to pave the way for the adoption of the Milan System for Reporting Salivary Gland Cytopathology.