Sporadic neurofibroma of facial nerve presenting as parotid gland tumor: a rare case report.

Intraparotid gland neurofibroma is a rare benign tumor that arises from Schwann cells of the facial nerve within the parotid gland. This case report discusses a 41-year-old woman who experienced a painless preauricular swelling on her right side for over 5 years. Clinical examination and ultrasound revealed a well-defined mass in the parotid gland. The patient underwent total mass excision, resulting in transient facial nerve dysfunction but complete recovery. These tumors often manifest as solitary masses in the parotid region and may compress nearby structures, causing facial paralysis or numbness. Their diagnosis can be challenging due to similarities with other parotid gland tumors and possible associations with neurofibromatosis. Managing intraparotid tumors, including neurofibromas, involves a multidisciplinary approach with input from cytopathologists, radiologists, and surgeons.

SMAS flap for extracapsular dissection of parotid gland tumors: is it necessary?

OBJECTIVE: The aim of this retrospective article is to evaluate postoperative outcomes after extracapsular dissection for small benign superficial parotid neoplasms (<3 cm) in patients who received Superficial Musculoaponeurotic System (SMAS) flap and in patients who did not receive it. METHODS: Two groups were created and statistically compared regarding Frey's syndrome and aesthetic satisfaction by data collected through the POI-8 validated questionnaire and through an aesthetic satisfaction scale ranging from 1 to 10. The difference between these two groups was the utilization of SMAS flap. SMAS flap was harvested in one of these two group, meanwhile was not used in the other. RESULTS: The p-value analysis between group 1 and group 2 on these complications, resulted statistically not significant. Also, the aesthetic satisfaction resulted not statistically significant between group 1 and group 2. Gender, localization, and facial palsy resulted statistically correlated with the aesthetic satisfaction (p-value < 0.05). CONCLUSION: In conclusion, there is no statistical difference in the use of SMAS flap for benign parotid neoformations of the superficial lobe, with a diameter of less than 3 cm for which extracapsular dissection is adopted as a surgical technique.

Multi-feature Fusion Network on Gray Scale Ultrasonography: Effective Differentiation of Adenolymphoma and Pleomorphic Adenoma.

RATIONALE AND OBJECTIVES: to develop a deep learning radiomics graph network (DLRN) that integrates deep learning features extracted from gray scale ultrasonography, radiomics features and clinical features, for distinguishing parotid pleomorphic adenoma (PA) from adenolymphoma (AL) MATERIALS AND METHODS: A total of 287 patients (162 in training cohort, 70 in internal validation cohort and 55 in external validation cohort) from two centers with histologically confirmed PA or AL were enrolled. Deep transfer learning features and radiomics features extracted from gray scale ultrasound images were input to machine learning classifiers including logistic regression (LR), support vector machines (SVM), KNN, RandomForest (RF), ExtraTrees, XGBoost, LightGBM, and MLP to construct deep transfer learning radiomics (DTL) models and Rad models respectively. Deep learning radiomics (DLR) models were constructed by integrating the two features and DLR signatures were generated. Clinical features were further combined with the signatures to develop a DLRN model. The performance of these models was evaluated using receiver operating characteristic (ROC) curve analysis, calibration, decision curve analysis (DCA), and the Hosmer-Lemeshow test. RESULTS: In the internal validation cohort and external validation cohort, comparing to Clinic (AUC=0.767 and 0.777), Rad (AUC=0.841 and 0.748), DTL (AUC=0.740 and 0.825) and DLR (AUC=0.863 and 0.859), the DLRN model showed greatest discriminatory ability (AUC=0.908 and 0.908) showed optimal discriminatory ability. CONCLUSION: The DLRN model built based on gray scale ultrasonography significantly improved the diagnostic performance for benign salivary gland tumors. It can provide clinicians with a non-invasive and accurate diagnostic approach, which holds important clinical significance and value. Ensemble of multiple models helped alleviate overfitting on the small dataset compared to using Resnet50 alone.

Direct visualization of intraparotid facial nerve assisting in parotid tumor resection.

Precise recognition of the intraparotid facial nerve (IFN) is crucial during parotid tumor resection. We aimed to explore the application effect of direct visualization of the IFN in parotid tumor resection. Fifteen patients with parotid tumors were enrolled in this study and underwent specific radiological scanning in which the IFNs were displayed as high-intensity images. After image segmentation, IFN could be preoperatively directly visualized. Mixed reality combined with surgical navigation were applied to intraoperatively directly visualize the segmentation results as real-time three-dimensional holograms, guiding the surgeons in IFN dissection and tumor resection. Radiological visibility of the IFN, accuracy of image segmentation and postoperative facial nerve function were analyzed. The trunks of IFN were directly visible in radiological images for all patients. Of 37 landmark points on the IFN, 36 were accurately segmented. Four patients were classified as House-Brackmann Grade I postoperatively. Two patients with malignancies had postoperative long-standing facial paralysis. Direct visualization of IFN was a feasible novel method with high accuracy that could assist in recognition of IFN and therefore potentially improve the treatment outcome of parotid tumor resection.

Deep learning-assisted diagnosis of benign and malignant parotid tumors based on ultrasound: a retrospective study.

BACKGROUND: To develop a deep learning(DL) model utilizing ultrasound images, and evaluate its efficacy in distinguishing between benign and malignant parotid tumors (PTs), as well as its practicality in assisting clinicians with accurate diagnosis. METHODS: A total of 2211 ultrasound images of 980 pathologically confirmed PTs (Training set: n = 721; Validation set: n = 82; Internal-test set: n = 89; External-test set: n = 88) from 907 patients were retrospectively included in this study. The optimal model was selected and the diagnostic performance evaluation is conducted by utilizing the area under curve (AUC) of the receiver-operating characteristic(ROC) based on five different DL networks constructed at varying depths. Furthermore, a comparison of different seniority radiologists was made in the presence of the optimal auxiliary diagnosis model. Additionally, the diagnostic confusion matrix of the optimal model was calculated, and an analysis and summary of misjudged cases' characteristics were conducted. RESULTS: The Resnet18 demonstrated superior diagnostic performance, with an AUC value of 0.947, accuracy of 88.5%, sensitivity of 78.2%, and specificity of 92.7% in internal-test set, and with an AUC value of 0.925, accuracy of 89.8%, sensitivity of 83.3%, and specificity of 90.6% in external-test set. The PTs were subjectively assessed twice by six radiologists, both with and without the assisted of the model. With the assisted of the model, both junior and senior radiologists demonstrated enhanced diagnostic performance. In the internal-test set, there was an increase in AUC values by 0.062 and 0.082 for junior radiologists respectively, while senior radiologists experienced an improvement of 0.066 and 0.106 in their respective AUC values. CONCLUSIONS: The DL model based on ultrasound images demonstrates exceptional capability in distinguishing between benign and malignant PTs, thereby assisting radiologists of varying expertise levels to achieve heightened diagnostic performance, and serve as a noninvasive imaging adjunct diagnostic method for clinical purposes.

B1 Power Modification for Amide Proton Transfer Imaging in Parotid Glands: A Strategy for Image Quality Accommodation and Evaluation of Tumor Detection Feasibility.

BACKGROUND: In the application of APTw protocols for evaluating tumors and parotid glands, inhomogeneity and hyperintensity artifacts have remained an obstacle. This study aimed to improve APTw imaging quality and evaluate the feasibility of difference B1 values to detect parotid tumors. METHODS: A total of 31 patients received three APTw sequences to acquire 32 lesions and 30 parotid glands (one patient had lesions on both sides). Patients received T2WI and 3D turbo-spin-echo (TSE) APTw imaging on a 3.0 T scanner for three sequences (B1 = 2 µT, 1 µT, and 0.7 µT in APTw 1, 2, and 3, respectively). APTw image quality was evaluated using four-point Likert scales in terms of integrity and hyperintensity artifacts. Image quality was compared between the three sequences. An evaluable group and a trustable group were obtained for APTmean value comparison. RESULTS: Tumors in both APT2 and APT3 had fewer hyperintensity artifacts than in APT1. With B1 values decreasing, tumors had less integrity in APTw imaging. APTmean values of tumors were higher than parotid glands in traditional APT1 sequence though not significant, while the APTmean subtraction value was significantly different. CONCLUSIONS: Applying a lower B1 value could remove hyperintensity but could also compromise its integrity. Combing different APTw sequences might increase the feasibility of tumor detection.

Tumor localization is the important factor for recovery time of postoperative facial nerve paralysis in benign parotid surgery.

OBJECTIVE: Facial nerve paralysis is the most problematic complication of surgery for parotid tumors. This study aimed to examine the progress of recovery from postoperative transient facial nerve paralysis (POFNP). METHODS: Participants were 203 patients who developed POFNP after benign parotid surgery. A Kaplan-Meier showed the progress of recovery from paralysis. Factors involved in recovery were examined. For factors for which a significant difference was found, recovery from paralysis was examined over time. RESULTS: Rates of recovery from paralysis were as follows: 28.6% of patients at 1 month, 58.3% at 3 months, 85.9% at 6 months, and 95.1% at 12 months after surgery. Deep lobe tumors were shown to be significantly associated with delayed recovery from paralysis. The relationship between tumor location and the time of recovery from was that deep lobe tumors had a significantly worse recovery from paralysis at 4 and 5 months after surgery. CONCLUSION: Patients who develop POFNP must be informed about the progress of recovery and factors involved in recovery from paralysis. We believe that the results of the present study are a useful reference to that end.

Rare Presentation of Tuberculous Osteomyelitis of Mandibular Condyle Mimicking as Parotid Tumor: A Case Report.

Tuberculosis (TB) is a significant health problem and mortality in most developing countries. It is a chronic granulomatous disease caused by Mycobacterium tuberculosis and M. tuberculosis complex. It can be pulmonary form or Extra pulmonary form. Extrapulmonary tuberculosis involving temporomandibular joint is infrequent presentation of Skeletal TB. Here we present a rare case of extrapulmonary tuberculosis that was initially misdiagnosed as a parotid lesion due to atypical signs and symptoms and multiple in-conclusive FNAC reports. The final diagnosis was established by histopathological report.

Common Tumor in an uncommon location: Pleomorphic Adenoma of nasal cavity - a case Report.

Pleomorphic adenoma (PA) is the most common benign salivary gland tumor of which parotid gland involvement is the most common. PA may arise from minor salivary glands as well, however, PA is very rare in the sinonasal and nasopharyngeal areas. It usually affects middle aged females. They are frequently misdiagnosed due to high cellularity and myxoid stroma, leading to delay in diagnosis & further appropriate management. Here we present a case report of a female who presented with gradually progressive nasal obstruction, on examination found to have a nasal mass in right nasal cavity. Imaging was done and the nasal mass was excised. Histopathological report revealed a PA. Common tumor in an uncommon location: Pleomorphic adenoma of the nasal cavity - a case report.

An anatomy-aware framework for automatic segmentation of parotid tumor from multimodal MRI.

Magnetic Resonance Imaging (MRI) plays an important role in diagnosing the parotid tumor, where accurate segmentation of tumors is highly desired for determining appropriate treatment plans and avoiding unnecessary surgery. However, the task remains nontrivial and challenging due to ambiguous boundaries and various sizes of the tumor, as well as the presence of a large number of anatomical structures around the parotid gland that are similar to the tumor. To overcome these problems, we propose a novel anatomy-aware framework for automatic segmentation of parotid tumors from multimodal MRI. First, a Transformer-based multimodal fusion network PT-Net is proposed in this paper. The encoder of PT-Net extracts and fuses contextual information from three modalities of MRI from coarse to fine, to obtain cross-modality and multi-scale tumor information. The decoder stacks the feature maps of different modalities and calibrates the multimodal information using the channel attention mechanism. Second, considering that the segmentation model is prone to be disturbed by similar anatomical structures and make wrong predictions, we design anatomy-aware loss. By calculating the distance between the activation regions of the prediction segmentation and the ground truth, our loss function forces the model to distinguish similar anatomical structures with the tumor and make correct predictions. Extensive experiments with MRI scans of the parotid tumor showed that our PT-Net achieved higher segmentation accuracy than existing networks. The anatomy-aware loss outperformed state-of-the-art loss functions for parotid tumor segmentation. Our framework can potentially improve the quality of preoperative diagnosis and surgery planning of parotid tumors.

Neural network combining with clinical ultrasonography: A new approach for classification of salivary gland tumors.

OBJECTIVE: Little information is available about deep learning methods used in ultrasound images of salivary gland tumors. We aimed to compare the accuracy of the ultrasound-trained model to computed tomography or magnetic resonance imaging trained model. MATERIALS AND METHODS: Six hundred and thirty-eight patients were included in this retrospective study. There were 558 benign and 80 malignant salivary gland tumors. A total of 500 images (250 benign and 250 malignant) were acquired in the training and validation set, then 62 images (31 benign and 31 malignant) in the test set. Both machine learning and deep learning were used in our model. RESULTS: The test accuracy, sensitivity, and specificity of our final model were 93.5%, 100%, and 87%, respectively. There were no over fitting in our model as the validation accuracy was similar with the test accuracy. CONCLUSIONS: The sensitivity and specificity were comparable with current MRI and CT images using artificial intelligence.

Epstein-Barr Virus-Associated Lymphoepithelial Carcinoma Arising in a Salivary Sebaceous Lymphadenoma.

BACKGROUND: Lymphadenomas are rare benign tumors of the major salivary glands that are further classified as sebaceous and non-sebaceous. No association with viruses has been reported so far. Little is known about the mechanisms that allow lymphadenomas to undergo malignant transformation. Among these rare instances, there has never been a malignant transformation to Epstein-Barr virus (EBV)-associated lymphoepithelial carcinoma. METHODS: Clinical data of the reported case were retrieved from the patient's electronic medical record. Hematoxylin & eosin-stained slides, immunohistochemical tests, and in situ hybridization performed for routine diagnostic purposes were reviewed. RESULTS: We report a salivary gland sebaceous lymphadenoma in which the luminal components were mostly replaced by malignant epithelial cells with markedly atypical nuclear features. Presence of EBV was demonstrated in all components by EBER. The morphological and immunohistochemical findings were consistent with a lymphoepithelial carcinoma arising from a sebaceous lymphadenoma. CONCLUSION: We report the first case of an Epstein-Barr virus-associated lymphoepithelial carcinoma arising from a sebaceous lymphadenoma.

Parotid Acinic Cell Carcinoma as a Presentation of Birt-Hogg-Dube Syndrome.

Birt-Hogg-Dube syndrome (BHD) is a rare autosomal dominant disease classically associated with fibrofolliculomas, pulmonary cysts, spontaneous pneumothorax, and renal cancers. Information about its manifestation aside from the ones listed prior is limited. There have been several reports of BHD associated with parotid oncocytomas and rare benign epithelial tumors. Here, we report the first known case of BHD in association with parotid acinic cell carcinoma, a rare low-grade malignant tumor of salivary glands.

Proposal for a novel classification of benign parotid tumors based on localization.

OBJECTIVE: Postoperative facial nerve paralysis is the most problematic complication after surgical treatment of parotid tumors. Localization of tumors is highly relevant for the surgical approach, but existing classification systems do not focus on the association between localization and surgical technique. Therefore, we created a new localization-based classification system for benign parotid tumors and investigated the characteristics of tumors in each localization and the frequency of postoperative facial nerve paralysis by retrospectively applying the classification to previous cases. METHODS: First, we defined 6 portions of the parotid gland (upper, U; lower, L; posterior, P; anterior, A; superficial, S; deep, D) by dividing the transverse plane into an upper and lower portion at the mandibular marginal branch, the longitudinal plane into a posterior and anterior portion at the midline of the parotid anteroposterior diameter, and the sagittal plane into a superficial and deep portion along the course of the facial nerve. Then, we defined 8 locations by combining the 6 portions in all possible ways (i.e., U-P-S, U-P-D, U-A-S, U-A-D, L-P-S, L-P-D, L-A-S, L-A-D). We used this classification to define the tumor localization in 948 patients who had undergone partial superficial parotidectomy for benign parotid tumors and then investigated the incidence, histopathological type, signs/symptoms, diagnosis, surgery, and complications in each area. RESULTS: Pleomorphic adenomas comprised approximately 70% of tumors in the upper portion but only approximately 35% in the lower portion. The rate of postoperative facial nerve paralysis was significantly higher for tumors in deep locations than in superficial locations (33.9% vs 14.9%, respectively), and the odds ratios for postoperative facial nerve paralysis in the U-P-D and U-A-D locations were 7.6 and 4.8 compared to the L-P-S location. When maximum diameter, operation time, bleeding volume, sex (reference: female), and age were added as control variables, the odds ratios were 4.2 and 3.0. CONCLUSION: Determining tumor localization preoperatively with the new localization-based classification of parotid tumors is helpful not only for predicting the histopathological type but also for predicting surgical complications, particularly postoperative facial nerve paralysis.

Endoscope-Assisted Resection of Benign Parotid Tumors via Concealed Post-Auricular Sulcus Incision.

OBJECTIVES: To investigate the feasibility, safety, and effectiveness of endoscopic-assisted resection of benign parotid tumors via concealed post-auricular sulcus incision. METHODS: Between October 2019 and March 2021, eligible patients with diagnosed benign parotid tumors were prospectively included and randomly assigned to two groups: the endoscope-assisted post-auricular sulcus incision group (endoscope group) and the conventional Blair "S" incision group (conventional group). RESULTS: A total of 45 patients were finally included, including 24 subjects in the endoscope group and 21 subjects in the conventional group. No obvious differences were observed in basic information between these two groups of patients. The surgical incision length in endoscope group patients was 4.0 ± 0.4 cm, which was significantly shorter than that in conventional group patients, 10.3 ± 1.6 cm (p < 0.001). The total intraoperative blood loss, the first post-operative day drainage volume, the total post-operative drainage volume, and the total drainage days were all significantly lower in endoscope group patients than in conventional group patients (all p < 0.05). Among 3 months follow-ups, no local recurrence or residual tumor were found in both groups of patients, and there were none of them had permanent facial paralysis or parotid fistula. The self-evaluated appearance satisfaction VAS scores of endoscope group patients were all 0, which was significantly lower than that of conventional group patients, 4.7 ± 1.6 (p < 0.001). CONCLUSION: Compared with the conventional Blair "S" incision surgery, the endoscope-assisted resection of the benign parotid tumors via concealed post-auricular sulcus incision was safe and effective and showed advantages of faster recovery and better self-assessments of appearance satisfaction. LEVEL OF EVIDENCE: 2 Laryngoscope, 133:133-138, 2023.

Metastatic Neuroendocrine Tumors to Parotid Gland: Where Do They Come From?

Background. Metastasis to parotid gland occurs mostly from skin cancers of the head and neck region. Metastatic neuroendocrine tumors to the parotid gland are rare and not well studied so far. In this study, we undertook a retrospective review of secondary neuroendocrine tumors of the parotid diagnosed in our institution. The most common entities, primary tumor locations, their clinical presentations and histopathological features were analyzed. Methods. Cases of secondary neuroendocrine tumors to parotid diagnosed from August 1995 to Jan 2021 were retrieved from our institution's pathology databases, and their clinicopathological features were reviewed. Results. About 29% (120 of 420 cases) of parotid neoplasms were malignant, including 70 cases of parotid primary malignant tumors and 50 cases of metastases to parotid glands. Among metastatic tumors to the parotid glands, squamous cell carcinoma and melanoma of the head and neck region together accounted for about 78% of the cases. Only 11 of 50 metastatic tumors to the parotid were neuroendocrine carcinomas (22%). The most common primaries were poorly differentiated neuroendocrine carcinoma of lung (5 of 11 cases), including 4 cases of small cell carcinoma and one case of large cell neuroendocrine carcinoma. The second most common secondary tumor was Merkel cell carcinoma (4 of 11 cases, 36%) including one case of direct invasion from overlying skin. Medullary carcinoma of the thyroid comprised the rest of the metastases to the parotid (2 of 11 cases, 18%). Conclusion. Our results show that metastatic neuroendocrine carcinomas to the parotid gland account for about 22% of all metastatic tumors to the organ. Lung is the most common primary neuroendocrine carcinoma location. It is not uncommon for metastatic neuroendocrine carcinoma to present as the first sign of systemic clinical manifestation. Merkel cell carcinoma is the second most common entity that metastasizes to parotid, followed by medullary carcinoma of the thyroid.

Current status of diffusion-weighted imaging in differentiating parotid tumors.

Recently, diffusion-weighted imaging (DWI) is an essential magnetic resonance imaging (MRI) protocol for head and neck imaging in clinical practice as it plays an important role in lesion detection, tumor extension evaluation, differential diagnosis, therapeutic effect prediction, therapy evaluation, and recurrence diagnosis. Especially in the parotid gland, several studies have already attempted to achieve accurate differentiation between benign and malignant tumors using DWI. A conventional single-shot echo-planar-based DWI is widely used for head and neck imaging, whereas advanced DWI sequences, such as intravoxel incoherent motion, diffusion kurtosis imaging, periodically rotated overlapping parallel lines with enhanced reconstruction, and readout-segmented echo-planar imaging (readout segmentation of long variable echo-trains), have been used to characterize parotid tumors. The mean apparent diffusion coefficient values are easily measured and useful for assessing cellularity and histological characteristics, whereas advanced image analyses, such as histogram analysis, texture analysis, and machine and deep learning, have been rapidly developed. Furthermore, a combination of DWI and other MRI protocols has reportedly improved the diagnostic accuracy of parotid tumors. This review article summarizes the current state of DWI in differentiating parotid tumors.

Radiomic nomogram for discriminating parotid pleomorphic adenoma from parotid adenolymphoma based on grayscale ultrasonography.

Objectives: To differentiate parotid pleomorphic adenoma (PA) from adenolymphoma (AL) using radiomics of grayscale ultrasonography in combination with clinical features. Methods: This retrospective study aimed to analyze the clinical and radiographic characteristics of 162 cases from December 2019 to March 2023. The study population consisted of a training cohort of 113 patients and a validation cohort of 49 patients. Grayscale ultrasonography was processed using ITP-Snap software and Python to delineate regions of interest (ROIs) and extract radiomic features. Univariate analysis, Spearman's correlation, greedy recursive elimination strategy, and least absolute shrinkage and selection operator (LASSO) correlation were employed to select relevant radiographic features. Subsequently, eight machine learning methods (LR, SVM, KNN, RandomForest, ExtraTrees, XGBoost, LightGBM, and MLP) were employed to build a quantitative radiomic model using the selected features. A radiomic nomogram was developed through the utilization of multivariate logistic regression analysis, integrating both clinical and radiomic data. The accuracy of the nomogram was assessed using receiver operating characteristic (ROC) curve analysis, calibration, decision curve analysis (DCA), and the Hosmer-Lemeshow test. Results: To differentiate PA from AL, the radiomic model using SVM showed optimal discriminatory ability (accuracy = 0.929 and 0.857, sensitivity = 0.946 and 0.800, specificity = 0.921 and 0.897, positive predictive value = 0.854 and 0.842, and negative predictive value = 0.972 and 0.867 in the training and validation cohorts, respectively). A nomogram incorporating rad-Signature and clinical features achieved an area under the ROC curve (AUC) of 0.983 (95% confidence interval [CI]: 0.965-1) and 0.910 (95% CI: 0.830-0.990) in the training and validation cohorts, respectively. Decision curve analysis showed that the nomogram and radiomic model outperformed the clinical-factor model in terms of clinical usefulness. Conclusion: A nomogram based on grayscale ultrasonic radiomics and clinical features served as a non-invasive tool capable of differentiating PA and AL.

Pediatric parotidectomy outcomes: A 14-year multicenter study.

Objectives: Parotidectomy increases childhood challenges. This study aimed to determine the clinical profiles, investigations, and outcomes of pediatric patients who had undergone parotidectomy. Methods: A multicenter retrospective review of parotidectomy in pediatric patients between 2007 and 2020. Results: In 108 parotidectomies, the final diagnoses were benign (47.22%), malignant (36.11%), and non-neoplastic (16.67%). The incidence of facial palsy was 37.03%, which was significantly lower in the superficial group than that in the total parotidectomy group (p = .021). The incidence of facial nerve palsy was significantly higher in the malignancy group than that in the benign group (p = .035). Magnetic resonance imaging (MRI) detected malignancy with 92.8% overall accuracy, 83.3% sensitivity, and 100% specificity. The sensitivity and specificity of fine-needle aspiration (FNA) were 54.2% and 92.7%, respectively. Conclusions: Parotidectomy is commonly performed for benign and non-neoplastic diseases in pediatric patients. Facial nerve palsy is significantly associated with malignant tumors and total parotidectomy. MRI is the most accurate imaging modality for diagnosing malignant lesions. FNA exhibits moderate agreement with the final pathology. Level of Evidence: Level IV.