Identification of circRNAs expression profiles and functional networks in parotid gland of type 2 diabetes mouse.

BACKGROUND: Circular RNAs (circRNAs) are a novel kind of non-coding RNAs proved to play crucial roles in the development of multiple diabetic complications. However, their expression and function in diabetes mellitus (DM)-impaired salivary glands are unknown. RESULTS: By using microarray technology, 663 upregulated and 999 downregulated circRNAs companied with 813 upregulated and 525 downregulated mRNAs were identified in the parotid glands (PGs) of type2 DM mice under a 2-fold change and P < 0.05 cutoff criteria. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analysis of upregulated mRNAs showed enrichments in immune system process and peroxisome proliferator-activated receptor (PPAR) signaling pathway. Infiltration of inflammatory cells and increased inflammatory cytokines were observed in diabetic PGs. Seven differently expressed circRNAs validated by qRT-PCR were selected for coding-non-coding gene co-expression (CNC) and competing endogenous RNA (ceRNA) networks analysis. PPAR signaling pathway was primarily enriched through analysis of circRNA-mRNA networks. Moreover, the circRNA-miRNA-mRNA networks highlighted an enrichment in the regulation of actin cytoskeleton. CONCLUSION: The inflammatory response is elevated in diabetic PGs. The selected seven distinct circRNAs may attribute to the injury of diabetic PG by modulating inflammatory response through PPAR signaling pathway and actin cytoskeleton in diabetic PGs.

Histopathological comparison of Sjögren-related features between paired labial and parotid salivary gland biopsies of sicca patients.

OBJECTIVES: To compare focus score (FS) and other histopathological features between paired labial and parotid salivary gland biopsies in a diagnostic cohort of suspected Sjögren's disease (SjD) patients. METHODS: Labial and parotid salivary gland biopsies were simultaneously obtained from patients with sicca complaints, suspected of having SjD. Biopsies were formalin fixed and paraffin embedded. Sections were stained with haematoxylin & eosin (H&E) and for CD3, CD20, CD45, cytokeratin, CD21, Bcl6, activation induced deaminase (AID), and IgA/IgG. FS and other histopathological features characteristic for SjD were analysed. RESULTS: Based on the expert opinion of three experienced rheumatologists, 36 patients were diagnosed as SjD and 63 as non-SjD sicca patients. When taking all patients together, absolute agreement of various histopathological features between labial and parotid biopsies was high and varied between 80% (FS) and 93% ((pre-)lymphoepithelial lesions (LELs)). More labial gland biopsies had a FS ≥ 1 compared with their parotid counterpart. Accordingly, the area of infiltrate was larger in labial gland biopsies. When considering only SjD patients, labial glands contained significantly less B-lymphocytes, GCs/mm2 and less severe LELs compared with parotid glands. CONCLUSION: Labial and parotid glands from SjD patients contain similar histopathological key features, and thus both glands can be used for diagnosis and classification of SjD. However, parotid salivary glands reveal more evident B-lymphocyte related features, while labial glands exhibit more inflammation, which may be partially unrelated to SjD.

Application of the Milan system for reporting salivary gland cytopathology to core needle biopsies of the parotid gland.

AIMS: The Milan system for reporting salivary gland cytopathology was developed by an international group of experts and first published in 2018 with the goal to standardise reporting of salivary gland aspirates. Seven categories with distinct risks of malignancy were proposed. Core needle biopsies (CNB) of salivary glands are also common, but reporting lacks standardisation. Here we explore the feasibility of a Milan-like reporting system on CNB of the parotid gland. METHODS AND RESULTS: Our laboratory information system was searched for parotid gland CNBs from 2010 to 2021. Reports were translated into a Milan-like reporting system. When available, CNB findings were correlated with cytology and resection specimens. In order to compare the performance of CNB with fine-needle aspirations (FNA), we established a second cohort of cases consisting of parotid FNA with surgical follow-up. The risk of neoplasia (RON) and risk of malignancy (ROM) was calculated for FNA and CNB Milan categories using cases with follow-up resection. We analysed 100 cases of parotid gland CNB. Of these cases, 32 underwent subsequent resection, while 52 had concurrent FNA. A total of 20 cases had concurrent FNA and underwent follow-up resection. In 63 (63%) cases, a specific diagnosis was provided on CNB, with 18 cases undergoing follow-up resection having an accuracy rate of 94%. CONCLUSIONS: This study confirms the feasible of using a Milan-like system in the setting of parotid gland CNB with differentiation in RON and ROM. CNB allows assessment of architectural features that may allow more specific diagnoses in some cases.

FGFR1/2/3-rearranged carcinoma of the head and neck: expanded histological spectrum crossing path with high-risk HPV in the sinonasal tract.

AIMS: Oncogenic FGFR1/2/3 rearrangements are found in various cancers. Reported cases in head and neck (HN) are mainly squamous cell carcinomas (SCCs) with FGFR3::TACC3 fusions, a subset of which also harbour high-risk human papillomavirus (HPV). However, the knowledge of the clinicopathological spectrum of FGFR-rearranged head and neck carcinomas (FHNC) is limited. METHODS AND RESULTS: A retrospective MSK-fusion clinical sequencing cohort 2016-23 was searched to identify malignant tumours in the HN region harbouring FGFR1/2/3 fusion. FHNC were characterised by histological examination, immunohistochemistry and molecular analysis. Electronic medical records were reviewed. Three FHNC were identified. Two cases (cases 1 and 2) involved sinonasal tract and were high-grade carcinomas with squamous, basaloid, glandular and/or ductal-myoepithelial features. Case 1 arose in a 79-year-old man and harboured FGFR2::KIF1A fusion. Case 2 arose in a 58-year-old man, appeared as HPV-related multiphenotypic sinonasal carcinoma (HMSC), and was positive for FGFR2::TACC2 fusion and concurrent high-risk HPV, non-type 16/18. Case 3 was FGFR3::TACC3 fusion-positive keratinising SCCs arising in the parotid of a 60-year-old man. All three cases presented at stage T4. Clinical follow-up was available in two cases; case 1 remained disease-free for 41 months post-treatment and case 3 died of disease 2 months after the diagnosis. CONCLUSIONS: FHNC include a morphological spectrum of carcinomas with squamous features and may occur in different HN locations, such as parotid gland and the sinonasal tract. Sinonasal cases can harbour FGFR2 rearrangement with or without associated high-risk HPV. Timely recognition of FHNC could help select patients potentially amenable to targeted therapy with FGFR inhibitors. Further studies are needed (1) to determine if FGFR2 rearranged/HPV-positive sinonasal carcinomas are biologically distinct from HMSC, and (2) to elucidate the biological and clinical significance of FGFR2 rearrangement in the context of high-risk HPV.

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.

An ultrasound-based ensemble machine learning model for the preoperative classification of pleomorphic adenoma and Warthin tumor in the parotid gland.

OBJECTIVES: The preoperative classification of pleomorphic adenomas (PMA) and Warthin tumors (WT) in the parotid gland plays an essential role in determining therapeutic strategies. This study aims to develop and validate an ultrasound-based ensemble machine learning (USEML) model, employing nonradiative and noninvasive features to differentiate PMA from WT. METHODS: A total of 203 patients with histologically confirmed PMA or WT who underwent parotidectomy from two centers were enrolled. Clinical factors, ultrasound (US) features, and radiomic features were extracted to develop three types of machine learning model: clinical models, US models, and USEML models. The diagnostic performance of the USEML model, as well as that of physicians based on experience, was evaluated and validated using receiver operating characteristic (ROC) curves in internal and external validation cohorts. DeLong's test was used for comparisons of AUCs. SHAP values were also utilized to explain the classification model. RESULTS: The USEML model achieved the highest AUC of 0.891 (95% CI, 0.774-0.961), surpassing the AUCs of both the US (0.847; 95% CI, 0.720-0.932) and clinical (0.814; 95% CI, 0.682-0.908) models. The USEML model also outperformed physicians in both internal and external validation datasets (both p < 0.05). The sensitivity, specificity, negative predictive value, and positive predictive value of the USEML model and physician experience were 89.3%/75.0%, 87.5%/54.2%, 87.5%/65.6%, and 89.3%/65.0%, respectively. CONCLUSIONS: The USEML model, incorporating clinical factors, ultrasound factors, and radiomic features, demonstrated efficient performance in distinguishing PMA from WT in the parotid gland. CLINICAL RELEVANCE STATEMENT: This study developed a machine learning model for preoperative diagnosis of pleomorphic adenoma and Warthin tumor in the parotid gland based on clinical, ultrasound, and radiomic features. Furthermore, it outperformed physicians in an external validation dataset, indicating its potential for clinical application. KEY POINTS: • Differentiating pleomorphic adenoma (PMA) and Warthin tumor (WT) affects management decisions and is currently done by invasive biopsy. • Integration of US-radiomic, clinical, and ultrasound findings in a machine learning model results in improved diagnostic accuracy. • The ultrasound-based ensemble machine learning (USEML) model consistently outperforms physicians, suggesting its potential applicability in clinical settings.

Partial facial paralysis induced by sialolithiasis of the parotid gland: a case report.

BACKGROUND: Facial paralysis due to parotid sialolithiasis-induced parotitis is a unusual clinical phenomenon that has not been reported in prior literature. This scenario can present a diagnostic challenge due to its rarity and complex symptomatology, particularly if a patient has other potential contributing factors such as facial trauma or bilateral forehead botox injections as in this patient. This case report elucidates such a complex presentation, aiming to increase awareness and promote timely recognition among clinicians. CASE PRESENTATION: A 56-year-old male, with a medical history significant for hyperlipidemia, recurrent parotitis secondary to parotid sialolithiasis, and recent bilateral forehead cosmetic Botox injections presented to the emergency department with right lower facial drooping. This onset was about an hour after waking up and was of 4 h duration. The patient also had a history of a recent ground level fall four days prior that resulted in facial trauma to his right eyebrow without any evident neurological deficits in the region of the injury. A thorough neurological exam revealed sensory and motor deficits across the entirety of the right face, indicating a potential lesion affecting the buccal and marginal mandibular branches of the facial nerve (CN VII). Several differential diagnoses were considered for the lower motor neuron lesion, including soft tissue trauma or swelling from the recent fall, compression due to the known parotid stone, stroke, and complex migraines. An MRI of the brain was conducted to rule out a stroke, with no significant findings. A subsequent CT scan of the neck revealed an obstructed and dilated right Stensen's duct with a noticeably larger and anteriorly displaced sialolith and evidence of parotid gland inflammation. A final diagnosis of facial palsy due to parotitis secondary to sialolithiasis was made. The patient was discharged and later scheduled for a procedure to remove the sialolith which resolved his facial paralysis. CONCLUSIONS: This case emphasizes the need for a comprehensive approach to the differential diagnosis in presentations of facial palsy. It underscores the potential involvement of parotid sialolithiasis, particularly in patients with a history of recurrent parotitis or facial trauma. Prompt recognition of such uncommon presentations can prevent undue interventions, aid in timely appropriate management, and significantly contribute to the patient's recovery and prevention of long-term complications.

MR-Neurography of the facial nerve in parotid tumors: intra-parotid nerve visualization and surgical correlation.

PURPOSE: One of the most severe complications in surgery of parotid tumors is facial palsy. Imaging of the intra-parotid facial nerve is challenging due to small dimensions. Our aim was to assess, in patients with parotid tumors, the ability of high-resolution 3D double-echo steady-state sequence with water excitation (DE3D-WE) (1) to visualize the extracranial facial nerve and its tracts, (2) to evaluate their relationship to the parotid lesion and (3) to compare MRI and surgical findings. METHODS: A retrospective study was conducted including all patients with parotid tumors, who underwent MRI from April 2022 to December 2023. Two radiologists independently reviewed DE3D-WE images, assessing quality of visualization of the facial nerve bilaterally and localizing the nerve's divisions in relation to the tumor. MRI data were compared with surgical findings. RESULTS: Forty consecutive patients were included (M:F = 22:18; mean age 56.3 ± 17.4 years). DE3D-WE could excellently visualize the nerve main trunk and the temporofacial division in all cases. The cervicofacial branch was visible in 99% of cases and visibility was good. Distal divisions were displayed in 34% of cases with a higher visibility on the tumor side (p < 0.05). Interrater agreement was high (weighted kappa 0.94 ± 0.01 [95% CI 0.92-0.97]). Compared to surgery accuracy of MRI in localizing the nerve was 100% for the main trunk, 96% for the temporofacial and 89% for the cervicofacial branches. CONCLUSIONS: Facial nerve MR-neurography represents a reliable tool. DE3D-WE can play an important role in surgical planning of patients with parotid tumors, reducing the risk of nerve injury.

Ultrasound-guided percutaneous thermal ablation of parotid tumors: experience from two-centers.

Objective: To evaluate the efficacy and feasibility of ultrasound-guided percutaneous thermal ablation (TA) for treating benign parotid tumors.Methods: Patients with benign parotid tumors who underwent ultrasound-guided microwave ablation (MWA) or radiofrequency ablation (RFA) between January 2020 and March 2023 were included in this retrospective study. Change in tumor size (maximum diameter, tumor volume(V), volume reduction rate (VRR)) and cosmetic score (CS) were evaluated during a one-year follow-up period. We also recorded the incidence of any complications associated with TA.Results: A total of 23 patients (13 males and 10 females; median age 65 years, range 5-91 years) were included. The mean VRR at 1, 3, 6, and 12 months after TA was 37.03%±10.23%, 56.52%±8.76%, 82.28%±7.89%, and 89.39%±6.45%, respectively. Mean CS also changed from 3.39 ± 0.66 to 1.75 ± 0.93 (p < 0.001) by the end of follow-up time. Subgroup analysis showed that tumors with smaller initial maximum diameter had a faster CS reduction rate than those with larger initial diameter. The incidence of facial nerve dysfunction was 8.70%.Conclusion: Ultrasound-guided percutaneous TA is an effective and safe treatment option for patients with benign parotid tumors.

Carcinoma showing thymus-like elements (CASTLE) with amyloid deposition in the parotid gland.

Carcinoma showing thymus-like elements (CASTLE) is a rare tumor that commonly occurs in the thyroid gland. Extrathyroidal CASTLE is rarer, and only 11 cases of CASTLE of major salivary glands have been reported to date. We report the first case of amyloid deposition in parotid CASTLE. A 63-year-old man presented with a slowly growing mass in the left parotid region. Computed tomography revealed an approximately 28 × 23 mm mass lesion in the left parotid gland, and squamous cell carcinoma was suspected on biopsy. The patient underwent a parotidectomy with neck dissection. Morphologically, the tumor cells were squamoid and formed nests with lymphoid infiltration. Immunohistochemically, the tumor cells exhibited immunoreactivity for CD5, CD117/c-kit and Bcl-2, p40, and CK5 but not for p16. We diagnosed the tumor as parotid CASTLE. Amyloid deposition was also observed in the primary tumor and metastatic lymph node lesions, which were immunoreactive for cytokeratin 5. Tumor cytokeratin-derived amyloid deposition may be one of characteristics of parotid CASTLE.

Lymphatic drainage patterns of malignant skin tumors in the head and neck region: a single-center retrospective study.

BACKGROUND: This study aimed to clarify the relationship between primary site and lymphatic drainage pattern for malignant skin tumors in the head and neck region. Malignant melanoma and squamous cell carcinoma in the head and neck region are known to have poor prognosis because of lymph node metastasis. Nevertheless, numerous aspects of lymphatic drainage patterns remain elusive. METHODS: We statistically analyzed data of 47 patients with malignant skin tumors in the head and neck region. Information was collected on the patients' clinical characteristics, primary tumor site, and lymphatic drainage patterns. RESULTS: The parotid lymph nodes drained the greatest amount of lymph from skin tumors of the head and neck. Important lymphatic drainage pathways were the superficial cervical nodes for primary tumors in the buccal/nasal region, level IA and level IB nodes for primary tumors in the lip region, the occipital nodes, posterior auricular nodes, and level VA nodes in the parietal/occipital region, and the preauricular nodes in the auricular region. CONCLUSION: These findings have considerable significance in terms of understanding lymphatic drainage patterns for malignant skin tumors in the head and neck and may be useful for clinical decision-making and when planning treatment. Further research and clinical applications are expected to contribute to an improved prognosis in patients with cutaneous head and neck malignancies.

Rapamycin alleviates irradiation-induced parotid injury by enhancing the whole gland homeostasis.

OBJECTIVES: Salivary gland injury is one of the most common complications of radiotherapy in head-and-neck cancers. This study investigated the mechanism by which rapamycin prevents irradiation (IR)-induced injury in the parotid glands. MATERIALS AND METHODS: Miniature pigs either received (a) no treatment (NT), (b) IR in the right parotid gland for 5 consecutive days (IR), or intraperitoneal administration of rapamycin (Rap) 1 h prior to IR (IR + Rap). Tissues were collected at three distinct time points (24 h, 4 weeks, and 16 weeks) after IR. Histological analyses, western blot, and real-time reverse transcriptase-polymerase chain reaction were performed to explore the mechanisms of IR-induced injury in the parotid gland. RESULTS: Rapamycin treatment maintained parotid salivary flow 16 weeks post-IR, preserved the number of acinar cells, and reduced parotid tissue fibrosis, as well as reduced apoptosis levels, decreased cleaved caspase-3 expression, and increased the Bcl-2/Bax ratio in the parotid glands. Autophagy marker LC3B was upregulated by rapamycin after IR, while P62 expression was downregulated. Rapamycin reduced the expression of pro-inflammatory factors and the mesenchymal tissue fibrosis following IR. CONCLUSIONS: Rapamycin maintains gland homeostasis after IR by decreasing apoptosis, reducing the expression of pro-inflammatory factors, and enhancing autophagy.

A case of renal sarcoidosis complicated by parotid gland and uterine lesions.

BACKGROUND: Sarcoidosis is a systemic disease that can affect multiple organs. While pulmonary sarcoidosis is most commonly observed, renal sarcoidosis occurs less frequently. We herein report a case of sarcoidosis with an exceptionally rare distribution including renal lesions. CASE PRESENTATION: A 51-year-old Japanese female was referred because of bilateral parotid swelling and renal dysfunction. Computed tomography scan showed the swelling of bilateral kidneys, parotid glands, and uterus. Ga scintigraphy also showed remarkable accumulation in these organs. Renal biopsy and cytological evaluations of parotid gland and uterus were performed and she was diagnosed as sarcoidosis of these organs. Treatment was initiated with prednisolone 40 mg/day and then renal dysfunction subsequently improved. In addition, the swelling of parotid glands and uterus improved and Ga accumulation in each organ had disappeared. CONCLUSION: This is a first case of renal sarcoidosis complicated by parotid glands and uterus lesions. Pathological findings and the reactivity observed in Ga scintigraphy indicated the presence of lesions in these organs.

Growth rates over time of unoperated parotid benign tumors.

INTRODUCTION: The treatment of parotid benign tumor is in principle surgery, but observation may be necessary in some cases. The purpose of this study was to investigate the growth rates over time of unoperated parotid benign tumors. METHODS: We retrospectively reviewed the medical records of 63 patients with unoperated parotid benign tumors diagnosed at our institution between January 2010 and December 2022. RESULTS: Forty-nine of the 63 patients had a Warthin tumor and 13 patients had a pleomorphic adenoma. On average, the unoperated parotid benign tumors grew 0.02 cm in length and 0.4 cm3 in volume per year. Compared to pleomorphic adenomas, Warthin tumors were more predominant in male patients and in those with a smoking history and a longer duration of smoking history; patients with Warthin tumors were also followed up longer (p < 0.05). However, the length and volume growth rates of unoperated Warthin tumors and pleomorphic adenomas did not significantly differ. CONCLUSION: Surgery is the standard treatment for parotid benign tumors. However, small benign parotid tumors identified during preoperative examination can be observed through close follow-up, taking into account the patient's medical and general condition.

Partial superficial parotidectomy for pleomorphic adenoma of the parotid gland: Early post-operative outcomes.

INTRODUCTION: There has been historical controversy regarding the extent of resection in the management of pleomorphic adenomas. This study aims to evaluate the extent of surgery and short-term postoperative outcomes of partial superficial parotidectomy (PSP) for the management of pleomorphic adenomas at a tertiary, high-volume center. METHODS: A retrospective chart review of patients who underwent PSP was performed. Variables included demographics, pre-operative facial nerve function, operative techniques, postoperative complications/facial nerve function, and recurrence. RESULTS: 151 adults who underwent PSP for pleomorphic adenoma from January 1st, 2000 to December 31st, 2022 were identified. Median age was 55 (IQR 40-66) years with females representing 74 % of the cohort. Median tumor size at presentation was 1.8 (IQR 1.3-2.3) cm. Baseline facial nerve function was excellent for most patients (House-Brackmann I, 99 %). Most patients underwent a superficial inferior parotidectomy (88 %). Modified Blair incision (70 %) was the most common incision. Intraoperatively, the facial nerve was identified in 149 (99 %) patients. The main trunk was identified in 126 (85 %) patients. No patient had tumor spillage. Only two patients required parotid bed reconstruction. The most common complication was ear numbness (60 %). Postoperatively, 114 patients were House-Brackmann grade I at both preoperative and postoperative assessment, 8 went from grade I to II, and 1 went from grade VI to II (Bell's palsy that resolved to grade II following surgery). Median follow-up was 1(IQR 1-5) month. CONCLUSION: PSP is efficacious in the management of pleomorphic adenomas with preservation of facial nerve function, and minimal post-operative complications. Future study is needed to assess long term recurrence risk.

Case-tailored indicated extracapsular dissection versus "one-size-fits-all" nerve dissection: Has the bet been won?

OBJECTIVE: The aim of the study was to trace the development of surgical therapy in a large cohort, examine its changes at one single institution that has been specializing in salivary gland pathologies over the last 22 years, and to determine the extent to which a possible shift in the surgical therapy of parotid benign tumors towards less radical methods was correlated with a change in the incidence of facial palsy and Frey's syndrome. STUDY DESIGN: Retrospective clinical study. METHODS: A retrospective evaluation of the records of all patients treated for benign parotid tumors at a tertiary referral center between 2000 and 2022 was carried out. Surgical methods were classified into four groups: extracapsular dissection, partial superficial parotidectomy, superficial parotidectomy and complete parotidectomy. RESULTS: A total of 4037 patients were included in the study. Our analysis demonstrated an increase in the total number of parotidectomies for benign lesions from 71 (2000) to 298 (2022), mostly due to the increase in extracapsular dissections (from 9 to 212). The increased performance of less radical surgery was associated with a significantly decreased incidence of perioperative complications. CONCLUSIONS: Our study showed that the increased performance of less radical surgery was associated with better functional outcomes over the years.

Elective nodal dissection for cN0 intermediate-grade parotid mucoepidermoid carcinoma: A NCDB study.

PURPOSE: To determine the occult nodal disease rate and whether elective regional lymph node dissection (RLND) confers any 10-year overall survival (OS) in cN0 intermediate-grade mucoepidermoid carcinoma (MEC) of the parotid gland. MATERIALS & METHODS: The National Cancer Database was reviewed from 2004 to 2016 on adults with cT1-4aN0M0 intermediate-grade parotid MEC undergoing resection with/without RLND. Comparisons between patients with and without RLND were made. Occult nodal rate and 10-year overall survival (OS) were determined. RESULTS: Out of 898 included patients with cN0 intermediate grade parotid MEC undergoing elective RLND, the occult nodal rate was 7.6%. This was significantly different from low-grade (3.9%) and high-grade (25.7%) cN0 disease. When stratified by pT-classification, marginal differences were identified between low-grade and intermediate-grade tumors, whereas high-grade tumors demonstrated increased occult nodal disease with low T-stage (pT1-pT2, 20.4% vs. 5.1%) and high T-stage (pT3-pT4a, 32.1% vs. 17.6%). Patients undergoing elective RLND were more often treated at an academic facility (53.8% vs. 41.2%), had higher pT3-pT4 tumors (19.2% vs. 10.4%), and more frequently underwent total/radical parotidectomy (46.0% vs. 29.9%) with adjuvant radiation therapy (53.8% vs. 41.0%) Cox-proportional hazard modeling did not identify RLND, regardless if stratified by nodal yield or pT-classification, nor nodal positivity as significant predictors of 10-year OS. CONCLUSIONS: The occult nodal disease in intermediate-grade parotid MEC is low and similar to low-grade. Elective RLND may have a limited impact on OS, though its effect on locoregional control remains unknown. LEVEL OF EVIDENCE: III.

Intra-parotid facial nerve path by MRI tractography: radio-clinical comparison in parotid tumors.

PURPOSE: The objective of our study was to evaluate the ability of preoperative MRI tractography to visualize and predict the path of the facial nerve with respect to an intra-parotid mass. METHODS: We performed an observational bicentric study from June 2019 to August 2020. All patients older than 18 years old, treated for a parotid mass with surgical indication, without MRI contraindication and who agreed to participate in the study were enrolled prospectively. All patients underwent a cervico-facial MRI with tractographic analysis. Postprocessed tractography images of the intra-parotid facial nerve were analyzed by two expert radiologists in head and neck imaging. The intraoperative anatomical description of the facial nerve path and its relationship to the mass was performed by the surgeon during the operation, with no visibility on MRI examination results. A statistical study allowed for the description of the data collected as well as the measurement of inter-observer agreement and agreement between tractography and surgery using kappa coefficients. RESULTS: Fifty-two patients were included. The facial nerve trunk and its first two divisional branches were visualized via tractography in 93.5% of cases (n = 43). The upper distal branches were visualized in 51.1% of cases (n = 23), and the lower branches were visualized in 73.3% of cases (n = 33). Agreement with the location described per-operatively was on average 82.9% for the trunk, 74.15% for the temporal branch, and 75.21% for the cervico-facial branch. CONCLUSION: Fiber tractography analysis by MRI of the intra-parotid facial nerve appears to be a good test for predicting the path of the nerve over the parotid mass and could be an additional tool to guide the surgeon in the operative procedure.

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.

Oncologic outcomes of the most prevalent major salivary gland cancers: retrospective cohort study from single center.

BACKGROUND: The preoperative diagnosis of salivary gland cancer (SGC) is crucial for the application of appropriate treatment, particularly involving the extension of the resection. METHODS: Retrospective search of medical database identified 116 patients treated surgically with malignant tumors of salivary gland between 2010 and 2020. Analysis included the demographical data, clinical course, type of surgical and adjuvant treatment, histology type and margin status, perivascular invasion (LVI), perineural invasion (PNI), metastatic lymph nodes (LN). Facial nerve function, recurrence-free and overall survival were evaluated. Adequate statistics were used for data analysis. RESULTS: The final cohort included 63 SGC patients, with adenoid cystic carcinoma the most common pathological type (27%, n = 17), followed by adenocarcinoma (17.4% n = 11). T1 and T2 patients accounted for majority cases (n = 46). The lymph node metastases were confirmed with the histopathology in 31.7% (n = 20). Distant metastases were observed in 4.8% of cases (n = 3). 38% (n = 24) of SGC were treated selectively with surgery, 49.2% (n = 31) had postoperative radiotherapy and 15.9% (n = 10)-radio-chemotherapy. The final facial nerve function was impaired in 38% of patients. Mean overall survival (OS) for all patients was 108.7 (± 132.1) months, and was the most favorable for acinar cell carcinoma (118.9 ± 45.4) and the poorest for squamous cell carcinoma (44 ± 32). Cox regression analysis of disease-free survival and OS identified significant association only with patients' age over 65 years, the hazard ratio of 7.955 and 6.486, respectively. CONCLUSIONS: The efficacy of treatment modalities for SGC should be verified with regard to the histopathological type, but also the patients' age should be taken into account.