Facial Nerve Injury after Extracapsular Dissection for Benign Parotid Tumors with and without Intraoperative Monitoring: A Retrospective Study of a Single Center.

BACKGROUND: Facial nerve injury (FNI) is the most common complication of parotid surgery and manifests as FN paralysis. The use of intraoperative facial nerve monitoring (IFNM) is becoming an established intraoperative aid for surgeons, assisting in the identification of the location and dissection of the facial nerve trunk or branches. The postoperative outcomes of parotid surgery with and without monitoring have been addressed in only a limited number of studies. OBJECTIVE: The objective of this study is to evaluate the incidence of postoperative paralysis in patients undergoing extracapsular dissection (ED) for benign parotid tumors concerning the use or non-use of IFNM. MATERIALS AND METHODS: The retrospective study was conducted at the Maxillo-Facial Department of the Magna Graecia University of Catanzaro. The patients were divided into two groups: Group 1 consisted of patients who underwent surgery without IFNM (1 January 2015 to 31 December 2018); Group 2, on the other hand, consisted of patients who underwent surgery with IFNM (1 January 2019 to 31 December 2022). Group 2 employed the Nerve Integrity Monitor (Medtronic's NIM®). To classify the FN function, we employed the modified House-Brackmann classification system. To evaluate the dependence between the "use of IFNM" and "postoperative paralysis", a descriptive analysis was conducted, including applying the Chi-squared test and calculating the Pearson correlation. Subsequently, a binary logistic regression model was applied to further evaluate the correlation between the latter. The level of statistical significance was set at p < 0.05. RESULTS: A total of 276 patients were included in the study: 120 subjects were assigned to Group 1 (43.5%, comprising 60 men and 60 women) and 156 subjects were assigned to Group 2 (56.5%, comprising 93 men and 63 women). In 91.7% of the cases (n. 253, precisely 105 in Group 1 and 148 in Group 2), no FNI occurred. In 8.33% of the cases (n. 23, specifically 15 in Group 1 and 8 in Group 2), postoperative paralysis was observed. Of these subjects, only two in Group 1 had permanent paralysis (8.69%); therefore, 91.31% had transient paralysis. As a result, 91.31% of the subjects exhibited transient paralysis. In the case of FNI, 78% of the cases involved the marginal mandibular branch (n. 18), 13% involved the temporo-zygomatic branch (n. 3), and 7% involved more than one branch (n = 2). The results of the multivariable binary logistic regression analysis demonstrated that the use of IFNM was a statistically significant influencing factor, with an estimated reduction in postoperative paralysis of approximately 62% (OR 0.378; 95% CI: 0.155-0.92). In Group 2, the occurrence of transient complications was significantly reduced (OR 0.387; 95% CI: 0.149-1.002 with p < 0.05). DISCUSSION AND CONCLUSIONS: The use of IFNM in the ED for benign parotid tumors significantly reduces the rate of FNI and, consequently, postoperative FN paralysis. On the other hand, the use of monitoring systems must not replace the experience and anatomical knowledge of the surgeon.

[Application of modified Z-shaped cosmetic incision in parotid benign tumor resection].

Objective:To explore the safety and aesthetic effect of modified Z-shaped cosmetic incision in parotid benign tumor resection. Methods:A prospective study was conducted. A total of 44 patients with benign parotid tumor resection were randomly divided into experimental group（n=22） and control group（n=22）. The experimental group underwent modified Z-shaped cosmetic incision, while the control group underwent the traditional S-shaped incision. The surgical duration, hospital stay, complications and maxillofacial aesthetics were compared between the two groups. Results:There was no significant difference in gender, age, surgical method, pathological type between the experimental group and the control group（P>0.05）. The maxillofacial aesthetics and surgical duration of the two groups was statistically significant（P<0.05）, while there was no statistically significant difference in terms of hospitalization days, surgical complications and Vancouver scar scale score （P>0.05）. Conclusion:The modified Z-shaped cosmetic incision has a better effect on improving the maxillofacial aesthetics after benign parotid tumor resection, and compared with the traditional S-shaped incision, the safety is consistent, so it is worthy of clinical promotion and application.

Modified buried vertical mattress suture technique for excisional suturing of benign parotid tumors: A retrospective study.

AIM: The purpose of this retrospective patient chart review was to analyze the clinical data of 52 patients with benign parotid tumors who underwent modified buried vertical mattress sutures and to assess the postoperative complication rate and patient scarring. METHODS: A total of 52 patients with benign parotid tumors underwent total parotidectomy and modified buried vertical mattress suture. Variables included general characteristics (age, gender, tumor diameter, and pathologic type), surgical indicators (suture time, wound healing time, operative time, hospital stay, bleeding volume, and drainage volume), complication rates, and Sunnybrook facial neurological function score, visual scar scale (VSS) score and patient and observer scar assessment scale (POSAS) score. RESULTS: Most tumors were less than 3 cm in diameter, with pleomorphic adenomas being the most common. Suture time was 14.83 ± 1.61 min, operative time was 58.90 ± 15.76 min and hospital stay were 5.12 ± 0.96 days. Postoperatively, salivary fistulae developed in one patient, Frey's syndrome in two patients, temporary facial paralysis in six patients and temporary numbness in the incision area in six patients. At 6 months postoperatively, 86.5% of patients had a Sunnybrook score of more than 80, and VSS scores and POSAS scores were between one and two. CONCLUSION: The postoperative complication rate was 30.8%, and the scarring in the facial incision area was mild and close to normal skin at 3 years postoperatively.

Parotid Enlargement as a Rare First Site of Manifestation in Extramedullary Acute Lymphoblastic Leukemia: A Case Report.

Parotid neoplasm in children is very rare, and most of these tumors are benign. Parotid enlargement in children is usually caused by infection or inflammation. We report a case of a 12-year-old boy who presented with the initial manifestation of bilateral parotid enlargement. He complained of two weeks of parotid swelling, during which the tumor gradually increased in size as he battled a monthlong on-and-off fever. An intravenous antibiotic was administered, as the first diagnosis was infection. Imaging studies of the swelling displayed features of infection, which was not resolved by the antibiotic. Fine-needle aspiration cytology was initially planned to establish a diagnosis. However, due to other findings in the clinical examination, such as bilateral scrotal swelling with abnormal blood work, the child was referred to other specialists for further assessment. Eventually, he was diagnosed with B-cell acute lymphoblastic leukemia by a hematology team.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.