Fine-needle aspiration cytology for parotid lesions, can we avoid surgery?

Warthin's Tumour as a Parotid Gland Incidentaloma Identified by PET-CT Scan in a Large Series of Cases

Occasionally in imaging scans there are findings unrelated to the pathology for which the scan was indicated, findings that are called incidentalomas. Warthin tumors have a high glucose avidity, being one of the common incidentalomas in PET-CT scans. The aim of the present study is to analyze the frequency of occurrence of Warthin's tumor as an incidental finding in a large series of patients undergoing 18F-FDG PET-CT. Retrospective analysis of 18F-FDG PET-CT scans performed in our center during the period 2010-2021. Parotid hypermetabolic lesions were identified, as well as their SUVmax, size, smoking habit, BMI (body mass index), and otorhinolaryngology follow-up. 31,423 PET-CT-18FDG studies corresponding to 12,806 patients were analyzed. The frequency of incidentalomas at the parotid level with a diagnosis compatible with Warthin's tumor was 0.87% (n = 111). Eighty percent of the patients with incidentalomas accordant to Warthin's tumor had a history of tobacco use. The highest percentage of incidentalomas compatible with a Warthin tumor was found in patients in whom the indication for PET-CT was the study of a lung carcinoma (1.44%). Only 37% of patients with a PET-CT lesion compatible with a Warthin's tumor were referred for evaluation by the Otorhinolaryngology service. The incidence of Warthin's tumor in 18-FDG PET-CT scans in our center was 0.87%.

Parotid Gland Segmentation Using Purely Transformer-Based U-Shaped Network and Multimodal MRI

Parotid gland tumors account for approximately 2% to 10% of head and neck tumors. Segmentation of parotid glands and tumors on magnetic resonance images is essential in accurately diagnosing and selecting appropriate surgical plans. However, segmentation of parotid glands is particularly challenging due to their variable shape and low contrast with surrounding structures. Recently, deep learning has developed rapidly, and Transformer-based networks have performed well on many computer vision tasks. However, Transformer-based networks have yet to be well used in parotid gland segmentation tasks. We collected a multi-center multimodal parotid gland MRI dataset and implemented parotid gland segmentation using a purely Transformer-based U-shaped segmentation network. We used both absolute and relative positional encoding to improve parotid gland segmentation and achieved multimodal information fusion without increasing the network computation. In addition, our novel training approach reduces the clinician's labeling workload by nearly half. Our method achieved good segmentation of both parotid glands and tumors. On the test set, our model achieved a Dice-Similarity Coefficient of 86.99%, Pixel Accuracy of 99.19%, Mean Intersection over Union of 81.79%, and Hausdorff Distance of 3.87. The purely Transformer-based U-shaped segmentation network we used outperforms other convolutional neural networks. In addition, our method can effectively fuse the information from multi-center multimodal MRI dataset, thus improving the parotid gland segmentation.

Clinical decision making when cytology indicates a Warthin tumor

Warthin tumor (WT) is a benign tumor usually affecting the parotid gland. The main diagnostic tool remains ultrasound combined with fine-needle aspiration cytology (FNAC). This study aims to examine how reliably FNAC indicates WT for clinical decision making regarding surgical versus conservative management. We included all patients who underwent FNAC from a parotid gland lesion between 2016 and 2018 at our institution, and whose FNAC revealed WT suspicion. The FNACs were divided into three groups based on the cytology report: certain, likely, and possible WT. The patients were divided into two groups based on having had either surgery or follow-up. We sent a questionnaire to patients who had not undergone surgery in order to obtain follow-up for a minimum of four years. Altogether, 135 FNAC samples, from 133 tumors and 125 patients, showed signs of WT. Of the 125 patients, 44 (35%) underwent surgery, and 81 (65%) were managed conservatively. Preoperative misdiagnosis in FNAC occurred in three (7%) surgically treated tumors. Their FNACs were reported as possible WTs, but histopathology revealed another benign lesion. In the conservatively treated group, two patients underwent surgery later during the follow-up. Cytological statements of WT were seldom false, and none were malignant. The majority of the patients were only followed-up and rarely required further treatment. A certain or likely diagnosis of WT in the FNAC report by an experienced head and neck pathologist is highly reliable in selecting patients for conservative surveillance.

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.

Incidence and spread pattern of lymph node metastasis from submandibular gland cancer

OBJECTIVES

To clarify the indication of neck dissection (ND) for patient with submandibular gland (SMG) cancer.

METHODS

A total of 43 patients with SMG cancer were retrospectively analyzed. Forty-one patients underwent ND: Levels I-V in 19 patients, Levels I-III in 18 patients, and Level Ib in 4 patients. The other two patients did not undergo ND, since preoperative diagnoses were benign. Postoperative radiotherapy was performed in 19 patients with positive surgical margin, high grade cancer or stage IV disease.

RESULTS

LN metastases were pathologically confirmed in all patients with cN + and 6 out of 31 patients with cN-. No patients developed regional recurrence during follow-up periods. Ultimately, LN metastases were pathologically confirmed in 17 of 27 high grade, one out of 9 intermediate grade, but not in 7 low grade.

CONCLUSIONS

Prophylactic neck dissection should be considered in T3/4 and high grade SMG cancers.

A Deep Learning Model for Classification of Parotid Neoplasms Based on Multimodal Magnetic Resonance Image Sequences

OBJECTIVE

To design a deep learning model based on multimodal magnetic resonance image (MRI) sequences for automatic parotid neoplasm classification, and to improve the diagnostic decision-making in clinical settings.

METHODS

First, multimodal MRI sequences were collected from 266 patients with parotid neoplasms, and an artificial intelligence (AI)-based deep learning model was designed from scratch, combining the image classification network of Resnet and the Transformer network of Natural language processing. Second, the effectiveness of the deep learning model was improved through the multi-modality fusion of MRI sequences, and the fusion strategy of various MRI sequences was optimized. In addition, we compared the effectiveness of the model in the parotid neoplasm classification with experienced radiologists.

RESULTS

The deep learning model delivered reliable outcomes in differentiating benign and malignant parotid neoplasms. The model, which was trained by the fusion of T2-weighted, postcontrast T1-weighted, and diffusion-weighted imaging (b = 1000 s/mm² ), produced the best result, with an accuracy score of 0.85, an area under the receiver operator characteristic (ROC) curve of 0.96, a sensitivity score of 0.90, and a specificity score of 0.84. In addition, the multi-modal paradigm exhibited reliable outcomes in diagnosing the pleomorphic adenoma and the Warthin tumor, but not in the identification of the basal cell adenoma.

CONCLUSION

An accurate and efficient AI based classification model was produced to classify parotid neoplasms, resulting from the fusion of multimodal MRI sequences. The effectiveness certainly outperformed the model with single MRI images or single MRI sequences as input, and potentially, experienced radiologists.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:327-335, 2023.

Trend changes in the incidence of benign parotid tumours in the last 30 years in a Spanish population

PURPOSE

To study the demographics and clinical characteristics of benign parotid tumours, focusing on the evolution of the incidence of Warthin tumour (WT) in recent years.

METHODS

A retrospective observational study is designed of patients diagnosed with a benign parotid tumour in a single tertiary hospital centre, from 1994 to 2021. The evaluation of the relationship between the different variables, and the changes in tumour incidence, is carried out using an analysis of standardized residuals.

RESULTS

The study evaluated 279 patients, and the total of benign parotid tumours was 291. The most frequent type of tumour was pleomorphic adenoma (PA) (52.7%), followed by WT (37.6%). WT was more frequent in men (79%), and PA in women (55.8%). Smoking history is significantly high in patients with WT (83%), as well as mid-age, compared to PA.

CONCLUSIONS

It seems to be an increase in the proportion of WT compared to PA in recent years. These changes can be concerning tobacco use and older patients at diagnosis in our series.

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.

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.

Experience with follow-up strategy in selected patients with Warthin tumour diagnosed by ultrasound-guided fine-needle aspiration biopsy (FNAB)

PURPOSE

Warthin tumour (WT) management options comprise surgery or follow-up. The purpose of this study was to asses our experience with the follow-up strategy in selected patients with an ultrasound-guided fine-needle aspiration biopsy (FNAB) showing WT.

METHODS

We performed a retrospective analysis of patients diagnosed with WT using FNAB between 1.1.2006 and 31.12.2019. Patients were divided into three groups according to the therapeutic approach-immediate surgery, follow-up or surgery and follow-up.

RESULTS

323 patients were diagnosed with WT and met the study's inclusion criteria (154 women, 47.7% and 169 men, 52.3%). 192 patients were operated right after the diagnosis, 109 patients were observed with their first detected tumour and 22 patients had parotid WT surgery and were in the wait-and-scan protocol with a contralateral tumour, recurrence or both. The growth rate (GR) of observed WT was highly variable (mean GR 1.0 mm/year (5%), median GR 0.8 mm (9%), range - 19.7 to +20.0 mm/year). From 131 patients in the follow-up group, 19 patients underwent surgery and definitive histology revealed 17 WTs and 2 adenocarcinomas. However, these 2 patients had changes in sonographic findings at their next control. The mean observation time was 44.7 months (range 12-138 months) in patients followed exclusively at our institution and 50.9 months (range 12-110 months) in patients observed in cooperation with an otorhinolaryngologist at the patients' place of residence.

CONCLUSION

Ultrasound-guided FNAB is an accurate and simple method in WT diagnosis and based on its result a follow-up strategy can be chosen for selected patients with WT.

Radiomic model for differentiating parotid pleomorphic adenoma from parotid adenolymphoma based on MRI images

Background

Distinguishing parotid pleomorphic adenoma (PPA) from parotid adenolymphoma (PA) is important for precision treatment, but there is a lack of readily available diagnostic methods. In this study, we aimed to explore the diagnostic value of radiomic signatures based on magnetic resonance imaging (MRI) for PPA and PA.

Methods

The clinical characteristic and imaging data were retrospectively collected from 252 cases (126 cases in the training cohort and 76 patients in the validation cohort) in this study. Radiomic features were extracted from MRI scans, including T1-weighted imaging (T1WI) sequences and T2-weighted imaging (T2WI) sequences. The radiomic features from three sequences (T1WI, T2WI and T1WI combined with T2WI) were selected using univariate analysis, LASSO correlation and Spearman correlation. Then, we built six quantitative radiomic models using the selected features through two machine learning methods (multivariable logistic regression, MLR, and support vector machine, SVM). The performances of the six radiomic models were assessed and the diagnostic efficacies of the ideal T1-2WI radiomic model and the clinical model were compared.

Results

The T1-2WI radiomic model using MLR showed optimal discriminatory ability (accuracy = 0.87 and 0.86, F-1 score = 0.88 and 0.86, sensitivity = 0.90 and 0.88, specificity = 0.82 and 0.80, positive predictive value = 0.86 and 0.84, negative predictive value = 0.86 and 0.84 in the training and validation cohorts, respectively) and its calibration was observed to be good (p > 0.05). The area under the curve (AUC) of the T1-2WI radiomic model was significantly better than that of the clinical model for both the training (0.95 vs. 0.67, p < 0.001) and validation (0.90 vs. 0.68, p = 0.001) cohorts.

Conclusions

The T1-2WI radiomic model in our study is complementary to the current knowledge of differential diagnosis for PPA and PA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-021-00581-9.

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.

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.

Regarding the "Is Surgery an Inevitable Treatment for Advanced Salivary Lymphoepithelial Carcinoma? Three Case Reports"

Salivary lymphoepithelial carcinoma is a highly radiosensitive tumor that suggests the effectiveness of induction chemotherapy and induction concurrent chemoradiotherapy without previous surgery. However, the imperfection of diagnostic methods and the severe consequences of misdiagnosis of the tumor do not allow to resign from surgical treatment in patients with this type of salivary gland tumor.

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.

Accuracy of fine-needle aspiration cytology of head and neck masses

BACKGROUND

Head and neck masses are a common presentation in daily practice and can be challenging to both clinicians and cytopathologists. Fine needle aspiration cytology (FNAC) is a widely used method for the diagnosis of head and neck masses. The aim of the study was to assess our institutional experience of the accuracy of FNAC in the diagnosis of head and neck masses.

METHODS

A total of 1262 FNACs were conducted from January 2013 to December 2016 and subdivided into benign and malignant categories. The thyroid and salivary glands FNACs were classified according to the Bethesda System for Reporting Thyroid cytopathology and to the Milan System for Reporting Salivary Gland Cytopathology respectively. The measures of diagnostic accuracy of FNAC were determined taking histology as a gold standard.

RESULTS

A total of 7 false negative (FN) and 6 false positive (FP) FNACs were identified. Overall sensitivity and specificity of FNAC for a malignant diagnosis were 92% and 94.4%, respectively. Accuracy of FNACs of head and neck masses was 93.5% for all sites. The salivary gland group had the highest rate of FN (2.8%). All FP were reported in the thyroid group. These cases were cytologically classified suspicious for malignancy (n = 3) and papillary carcinoma (n = 3) and proved to be lymphocytic thyroiditis on final histology. Among the most common locations, cytology of lymph nodes provided the best sensitivity (98.2%). Salivary glands as well as lymph nodes had the best specificity (100%).

CONCLUSION

FNAC of head and neck masses has a high accuracy allowing a correct therapeutic management. However, this accuracy depends on the anatomic location of the mass.