Identification and culture of functional salivary gland ductal epithelial cells.

Sialadenitis is a prevalent salivary gland disease resulting in decreased salivary flow rate. To date, little is known about the exact changes and mechanism of ductal cells in sialadenitis. This study aims to establish an efficient method to identify and isolate ductal cells, thereby facilitating further research on this specific cell type. Immunofluorescence for cytokeratin 13 and cytokeratin 19 was conducted in salivary glands to confirm their specificity as ductal cell markers. The dissected ducts were assessed through PCR and Western blot of cytokeratin 19 and digested by dispase and collagenase. The functionality of the isolated ductal cells was determined by measuring intracellular calcium. Cytokeratin 19 and cytokeratin 13 were expressed in all segments of human ducts. Cytokeratin 19 was limited to ducts excluding granular convoluted tubules in rat and mouse. The purities of the obtained ductal cells were approximately 98% in humans and 93% in rats. Furthermore, intracellular free calcium increased with time and concentration of carbachol treatment. Cytokeratin 19 serves as a dependable marker for identifying ductal cells in salivary glands, except for granular convoluted tubules. Moreover, we have successfully developed an efficient method for isolating ductal cells from salivary glands.

Comparative Efficacy and Side Effect Profiles of Interventions for Pediatric Saliva Control: A Cohort Study.

OBJECTIVE: To compare efficacy and side effect profile data on conservative, behavioral, pharmacological, and surgical treatments used for pediatric saliva control. STUDY DESIGN: A cohort study of children (n = 483) referred to a specialty Saliva Control service between May 2014 and November 2019 was performed, using quantitative data from pretreatment and post-treatment questionnaires (the Drooling Impact Scale [DIS], Drooling Rating Scale [DRS]) and recording of side effects. Overall, 483 children were included; treatment choices were based on published international guidelines. RESULTS: The greatest improvement was seen after intraglandular botulinum toxin A (BTX-A) injections (n = 207; 551 courses; mean DIS change, 34.7; 95% CI = 29.2-35.7) or duct transpositional surgery (n = 31; mean change in DIS, 29.0; 95% CI, 22.3-35.7). Oral anticholinergics were associated with good outcomes, with no significant statistical difference between glycopyrronium bromide (n = 150; mean DIS change, 21.5; 95% CI, 19.1-24.0) or trihexyphenidyl (n = 87; mean DIS change, 22.4; 95% CI, 18.9-25.8). Inhaled ipratropium bromide was not as efficacious (n = 80; mean DIS change, 11.1; 95% CI, 8.9-13.3). Oromotor programs were used in a selected group with reliable outcomes (n = 9; mean DIS change, 13.0). Side effects were consistent with previous studies. Overall, in cases of milder severity, enterally administered therapies provided a good first-line option. With more severe problems, BTX-A injections or saliva duct transpositional surgery were more effective and well tolerated. CONCLUSIONS: We describe a large, single-center pediatric saliva control cohort, providing direct comparison of the efficacy and side effect profiles for all available interventions and inform clinical practice for specialists when considering different options. BTX-A injections or saliva duct transpositional surgery seem to be more effective for saliva control that is more severe.

Salivary duct carcinoma with squamous differentiation: histomorphological and immunophenotypical analysis of six cases.

BACKGROUND AND AIMS: Salivary duct carcinoma (SDC) is an aggressive salivary malignancy with multiple morphological subtypes. Primary salivary squamous cell carcinoma (SCC) requires exclusion of high-grade salivary malignancies and metastatic disease and is considered exceptionally rare. We report six cases of SDC with resemblance to SCC on account of variable, but often extensive, squamous differentiation. METHODS AND RESULTS: A retrospective review (2009-2023) at two institutions of SDC with histological and immunophenotypical evidence of squamous differentiation identified six cases. Medical charts and available glass slides were reviewed. There were five males and one female with a median age of 63 years, with tumours involving the parotid (five of six) and submandibular (one of six) glands. All six tumours showed a conventional SDC component comprising < 5-90% of viable tumour. Squamous differentiation comprised 10-95%+ (> 75% in three of six cases) of total viable tumour, and demonstrated CK5/6, p63 and/or p40 immunoexpression in all cases. A sarcomatoid component, comprising 10-60% of viable tumour, was present in three of six (50%) cases. All tumours were androgen receptor (AR)-positive, but only two of six (33.3%) retained AR immunoreactivity in the squamous component. Metastatic SDC to regional lymph nodes exhibited exclusive squamous differentiation in two of six (33.3%) cases. CONCLUSION: Squamous differentiation, histologically and immunophenotypically, can be extensive in SDC. AR expression may be lost in the squamous component and metastases may demonstrate only squamous differentiation. These findings cast further doubt on the existence of primary salivary SCC. SDC should be considered whenever encountering a carcinoma with squamous differentiation in major salivary glands or within cervical lymph nodes in the setting of a salivary mass.

A randomized phase II trial on the addition of dutasteride to combined androgen blockade therapy versus combined androgen blockade therapy alone in patients with advanced or metastatic salivary duct carcinoma - the DUCT study protocol.

BACKGROUND: Salivary duct carcinoma (SDC) is a rare and aggressive subtype of salivary gland cancer, frequently associated with incurable recurrences and distant metastases (R/M). Proliferation of SDC relies on androgen receptor (AR) signalling, prompting the use of combined androgen blockade (CAB, i.e., luteinizing hormone-releasing hormone agonist and/or AR antagonists) to R/M SDC patients. However, only a subset of patients benefits from such treatments. We have shown that response to CAB is associated with steroid 5α-reductase 1 (SRD5A1) mRNA expression. SRD5A1 catalyses the intracellular conversion of testosterone into the more potent AR-agonist dihydrotestosterone. This conversion can be inhibited by dutasteride, a potent SRD5A1-inhibitor, which is currently prescribed for benign prostatic hyperplasia. We hypothesize that repurposing dutasteride to target AR signalling in SDC could enhance therapeutic response and clinical outcome in SDC patients. METHODS: This prospective, open-label, randomized controlled phase II clinical trial, is designed to investigate whether dutasteride as an adjunct drug to CAB improves response rate and clinical outcome in patients with AR-positive R/M SDC. Patients are divided in two cohorts based on their prior systemic treatments. In cohort A, CAB-naïve patients (n = 74) will be randomly assigned to either a control arm (Arm 1) receiving CAB (goserelin 10.8 mg/3m and bicalutamide 50 mg/OD) or an experimental arm (Arm 2) where dutasteride (0.5 mg/OD) is added to the CAB regimen. In cohort B, patients with disease progression after adjuvant or first-line palliative CAB therapy (max. n = 24) will receive goserelin, bicalutamide, and dutasteride to assess whether the addition of dutasteride can overcome therapy resistance. The primary endpoints are the objective response rate and duration of response. Secondary endpoints are progression-free survival, overall survival, clinical benefit rate, quality of life, and safety. Translational research will be performed to explore molecular target expression differences and their correlation with clinical outcome. DISCUSSION: The DUCT study addresses an unmet medical need by investigating the repurposing of dutasteride to enhance treatment response and improve clinical outcome for patients with R/M SDC, especially those with limited alternative treatment options, such as HER2-negative cases. By repurposing a registered low-cost drug, this trial's findings could be readily applied into clinical practice. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT05513365. Date of registration: August 24, 2022. PROTOCOL VERSION: Current protocol version 4.0, February 21, 2024.

Comparing botulinum toxin and 4-duct ligation for Sialorrhea in children - A systematic review.

INTRODUCTION: Sialorrhea or drooling can result in physical and psychosocial complications, such as aspiration and social isolation. Treatment options include botulinum toxin into the salivary glands and 4-duct ligation (i.e., simultaneous ligation of the bilateral parotid and submandibular ducts). This systematic review aimed to compare the efficacy and complication rates of botulinum toxin and 4-duct ligation for the treatment of drooling in children. METHODS: Following PRISMA guidelines, PubMed, Embase, Web of Science, and Cochrane Library were searched from inception through June 17, 2021 for studies examining the efficacy of botulinum toxin or 4-duct ligation for drooling in children. Data were summarized by pooled counts, percentages, and means. Complication rates were compared by a chi-squared test. RESULTS: A total of 22 studies (n = 606) examining botulinum toxin and 5 studies (n = 124) examining 4-duct ligation were included. From 12 botulinum toxin studies (n = 211), mean drooling frequency and severity scores was 7.5 at baseline. Mean difference from baseline was -2.6 (n = 92) at 4 weeks follow-up, -2.1 at 8 weeks (n = 41), -2.1 at 12 weeks (n = 56), and - 2.1 at 16 weeks (n = 58). From 4 4-duct ligation studies (n = 103), mean baseline drooling frequency and severity score was 8.4. Mean difference was -3.7 at mean follow-up of 35.6 months (n = 103). Eighteen botulinum studies (n = 343) recorded 53 (15.5 %) complications, including thickened saliva (n = 9), dysphagia (n = 4), and cheek abscesses (n = 4). Four 4-duct ligation studies (n = 108) recorded 25 (23.1 %) complications, including parotid gland swelling (n = 4), aspiration pneumonia (n = 3), and oxygen desaturation (n = 3). There was no statistically significant difference in complication rates between botulinum toxin and four-duct ligation (p = 0.065). CONCLUSION: Botulinum toxin injection and 4-duct ligation are both effective in improving sialorrhea in children and have comparable complication rates.

The extent of androgen receptor and HER2 expression allows for targeted therapy in most cases of salivary duct carcinoma: analysis of clinical and histopathological data in a tertiary care center.

PURPOSE: The incidence of salivary duct carcinoma (SDC) seems to be underestimated due to inaccurate classification. Further, the frequency of SDC patients with targeted therapy options according to current guidelines is unclear. Therefore, this study aimed at (a) describing the proportion of SDC among salivary gland carcinoma (SGC) before and after reclassification of cases initially classified as adenocarcinoma, not otherwise specified (ANOS); and (b) quantifying the frequency of SDC patients with targeted therapy options. METHODS: All patients with SDC or ANOS treated in a tertiary care center between 1996 and 2023 were identified. Histopathological diagnosis was verified for patients primarily diagnosed with SDC and reviewed for patients initially diagnosed with ANOS. Clinical data for SDC patients were retrieved from clinical charts. Immunohistochemical (IHC) androgen receptor (AR) and HER2 staining was performed. RESULTS: Among 46 SDC, 34 were primarily diagnosed as SDC and 12 had initially been classified as ANOS. The proportion of SDC among SGC was 12.1% and was rising when comparing the time periods 2000-2015 (7.1-11.5%) versus 2016-2023 (15.4-18.1%). Nuclear AR staining in > 70% of tumor cells was found in 56.8% and HER2 positivity (IHC 3 +) in 36.4% of cases. 70.5% of patients showed AR staining in > 70% of tumor cells and/or HER2 positivity and therefore at least one molecular target. 5-year overall and disease-free survival (DFS) were 62.8% and 41.0%. Multivariate Cox regression revealed positive resection margins (HR = 4.0, p = 0.03) as independent negative predictor for DFS. CONCLUSIONS: The results suggest a rising SDC incidence and show that the extent of the AR and HER2 expression allows for targeted therapy in most SDC cases.

MR sialographic assessment of the masseter muscle and the ductal kinking in patients with recurrent parotitis.

Dysfunction of the masseter muscle may cause pathological kinking of the parotid duct leading to parotitis; MR sialography is a non-invasive radiological examination that allows to evaluate dynamically the ductal system of the parotid glands. In the present study we aimed to assess the relationships between Stensen's duct and masseter muscle and their implications in the aetiopathogenesis of recurrent parotitis secondary to masseter muscle dysfunction. Forty-one patients with recurrent unilateral parotitis and nine with bilateral recurrent parotitis, all with a clinical suspicious of masseter muscle hypertrophy due to bruxism were enrolled. They underwent ultrasonography as a first line examination and then MR sialography and sialendoscopy. Different anatomical features were studied. Involved parotid glands had a wider duct compared to contralateral unaffected parotid glands of patients with recurrent parotitis (p = 0.00134); male subjects with parotitis had a longer duct compared to the salivary glands of healthy patients (p = 0.00943 for affected glands and p = 0.00629 for the contralateral). A concordance between the evidence of an acute duct angle during sialendoscopy and a wider duct in patients with parotitis was observed although not statistically significant. These initial findings suggest that the masticatory muscle dysfunction related to bruxism seems to condition alteration of parotid duct course and anatomy thus favouring the occurrence of recurrent parotitis. A specific diagnostic iter based on clinical evaluation, dynamic ultrasonography and MR sialography, is therefore, mandatory to confirm the relationship between masseter muscle anatomy and parotid duct anomalies; this is the premise for an adequate therapeutic approach to underlying masticatory muscle disorder.

The anterior lobe of the parotid gland: a CT sialographic study.

OBJECTIVES: To investigate the imaging and anatomic features of the anterior lobe (AL) of the superficial parotid gland (SPG). METHODS: Computed tomographic sialography examinations were undertaken for 142 parotid glands in 77 patients. Whole computer tomography (CT) data were analyzed using multi-planar reformation and maximum intensity projection to generate sialographic CT images. The tributary ducts of the SPG were analyzed to classify the parotid morphology. Three-dimensional analyses were used to investigate the AL and its relationship with adjacent anatomic landmarks. RESULTS: Four major types (I-IV) and 2 minor types (V-VI) of the AL and the superficial parotid gland were observed. Type I AL (83/142) was contiguous and not separated from the retromandibular parotid gland. Type II AL (16/142) was detached from the retromandibular parotid gland with 1-4 tributary ducts. Type III AL (12/142) showed a small isolated lobe above the Stensen duct around the anterior edge of the masseter. Type IV (28/142) showed the absence of the AL. Type V (3/142) shows the absence of the retromandibular parotid gland. Type VI (3/142) showed the presence of ectopic salivary gland beneath the Stensen duct anterior to the retromandibular parotid gland. CONCLUSIONS: The AL gives rise to the morphological variations of the superficial parotid gland. AL also gives rise to the accessory parotid gland when it is detached from the retromandibular parotid gland.

Comparative analysis of approaches to the Wharton's duct during surgery of the submandibular gland: A retrospective case-control study.

INTRODUCTION: We investigated complications and recurrence rates after surgical techniques for sialolith removal with intact and resected Wharton's duct of the submandibular gland. METHODS: The retrospective case-control analysis of a series analysed 271 surgical operations (2003-2022) for sialolithiasis performed at a hospital department of Otolaryngology-Head and Neck Surgery. The study compared two approaches: (1) pure endoscopic technique or pinpoint stone removal with Wharton's duct left intact and (2) transoral duct dissection or pinpoint stone removal technique, after which the duct was shortened. While choosing the surgical option, the size of the stone, the location of the stone, and the presence of multiple stones were taken into account. The rates of complications (lingual nerve paraesthesia, duct stenosis, drooling, and sialoadenitis), the incidence of foreign bodies, and the rate of recurrence during follow-up of ≥18 months were compared. RESULTS: 323 sialoliths were removed from 271 patients. Of these 323 calculi, 150 were removed by the first approach and 173 by the second approach. The calculi varied in diameter from 2 to 38 mm with an average diameter of 8.2 mm. For all 271 patients, the rate of recurrence was 4.8%, but 11 recurrent cases (8.7%) appeared after the first approach surgeries and 2 cases (1.4%) after the second approach surgeries (p = .03). Other variables did not show statistically significant differences. CONCLUSIONS: Surgical removal of the submandibular calculi, ending with shortening of Wharton's duct, reduces the recurrence rate for sialolithiasis but does not affect the rate of postsurgical complications.

Diagnosis and Surgical correction of salivary affections in buffaloes (Bubalus bubalis); a retrospective study.

AIM: This study aimed to describe the diagnosis and treatment of various surgical salivary affections in buffaloes. MATERIALS AND METHODS: This study included 135 buffaloes examined at Dakahlia Governorate between 2011 and 2022 suffering from various surgical salivary affections. The recorded surgical affections had salivary fistula (n = 44), ectasia of Stenson's duct (n = 11), ranula/mucocele (n = 46), and cervical sialocele (n = 34). The buffaloes were sedated using an intramuscular injection of xylazine (0.05 mg/kg) and local infiltration analgesia of lidocaine for specific surgical interventions. RESULTS: The salivary duct fistula cases were surgically corrected using a retrograde infusion of povidone-iodine into the duct and its double ligation with Prolene following fistulectomy. Intraoral marsupialization was done in buffaloes suffering from ectasia of the parotid duct. The mucocele /ranula was surgically incised with daily flushing with povidone-iodine. The cervical sialocele was treated by giving an elliptical excision on the sialocele, and sialoadenectomy of the mandibular salivary gland was performed to facilitate dynamic fluid/saliva drainage. A 92.5% of diseased buffaloes showed an uneventful recovery without any postoperative complications after the first treatment, whereas 7.5% of animals tended to recur. The most common and almost equally distributed salivary affections recorded in adult buffaloes were parotid duct fistula, mucocele, and cervical sialocele. The Stenson's duct ectasia was commonly registered in calves, being congenital. CONCLUSION: Ranula was the most common salivary affection encountered in adult buffaloes, closely followed by parotid duct fistulae and cervical sialoceles. Stenson's duct ectasia was the least encountered salivary affection in calves and was congenital. All salivary affections were corrected easily and safely, with satisfactory outcomes.

Sialin mediates submandibular gland regeneration ability by affecting polysialic acid synthesis.

OBJECTIVES: Sialin is a multifunctional molecule with a well-described role in physiological equilibrium regulation. The aim of this study was to elucidate the role of sialin in salivary glands regeneration. MATERIALS AND METHODS: Submandibular gland duct ligation/deligation of rat was performed to develop a rat model of submandibular gland regeneration. Phenotype changes were investigated using Western blotting and quantitative real-time polymerase chain reaction, as well as immunohistochemical staining. LV-slc17a5-RNAi vectors were injected into the submandibular glands via retroductal instillation to establish a stable sialin-knockdown model. RESULTS: Submandibular gland tissue structure could completely restore 28 days after duct deligation, when the duct had been ligated for 7 days. The expression of sialin, polysialic acid, and polysialyltransferase IV was significantly increased on Day 0 after duct deligation, and it returned to the level of the control group at Day 28. Moreover, sialin knockdown could weakened gland regeneration by reducing polysialic acid synthesis. Supplementing drinking water with polysialic acid precursors (ManNAc) in drinking water could partially rescue submandibular gland regeneration in sialin-knockdown rats. CONCLUSION: These data indicated that sialin was vital for submandibular gland regeneration which mediated the process of gland regeneration by affecting the polysialic acid synthesis.

Ultrasound-guided thread lifting for the prevention of parotid gland and diagnosing parotid duct complications.

BACKGROUND: Thread lifting is a common minimally invasive plastic surgery procedure. Parotid gland injury caused by thread lifting is a known complication; however, visual evidence of this complication is lacking. OBJECTIVES: This study aimed to present cases of parotid gland injury by thread lifting shown using ultrasound and to discuss the importance of ultrasound detection of the location of the parotid gland before thread insertion. METHODS: This study included eight patients diagnosed with parotid gland perforation and one with parotid duct injury due to threads from November 2020 to October 2022. RESULTS: Six patients showed tenderness and swelling, three were asymptomatic, and one with duct injury showed severe swelling and pain. Although the severity and duration of symptoms have differed, we confirmed the progress of improvement with conservative treatment and confirmed ultrasound findings progressed. CONCLUSIONS: Using ultrasound to detect the parotid gland's location before thread lifting might reduce the chance of parotid duct injury. Identifying immediate parotid duct or gland injury with ultrasound can help to act quickly for delayed pain or swelling and reduce the likelihood of additional complications.

Ultrasonographic Localization of Parotid Gland Tumor Relative to the Facial Nerve Using Stensen's Duct Criterion.

PURPOSE: During the preoperative evaluation of parotid gland tumors, one of the main concerns is to determine the location of the tumors in relation to the facial nerve. This study aims to assess the value of ultrasound for determining the location of parotid gland tumors in relation to the facial nerve using Stensen's duct. METHODS: This is a retrospective cross-sectional study at a single institute. The subjects who underwent preoperative ultrasound and parotidectomy for parotid gland tumors were included. The subjects with incomplete operative records or no reference standard for the location of parotid gland tumor were excluded. The primary predictor was ultrasound tumor location, which was defined as the location of parotid gland tumors determined by preoperative ultrasound as to whether the tumors were superficial or deep to the facial nerve. The operative records were used as the reference standard for the location of parotid gland tumors. The primary outcome was diagnostic performances of preoperative ultrasound in predicting the location of parotid gland tumors, which were calculated by comparing ultrasound tumor location to the reference standard. Covariates were sex, age, type of surgery, tumor size, and tumor histology. Data analysis involved descriptive and analytic statistics; P < .05 was considered statistically significant. RESULTS: One hundred and two of 140 eligible subjects met inclusion and exclusion criteria. There were 50 male and 52 female, with a mean age of 53.3 years. Ultrasound tumor location was classified as deep in 29 subjects, superficial in 50, and indeterminate in 23. The reference standard was deep in 32 subjects and superficial in 70. Indeterminate ultrasound tumor location results were grouped as either deep or superficial to make every possible cross table in which ultrasound tumor location results were presented as a dichotomy. The mean sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the ultrasound to predict the deep location of parotid tumors were 87.5, 82.1, 70.2, 93.6, and 83.8%, respectively. CONCLUSIONS: Stensen's duct on ultrasound can be a useful criterion to determine the location of parotid gland tumor relative to the facial nerve.

Prognostic models for estimating survival of salivary duct carcinoma: a population-based study.

PURPOSE: In a large salivary duct carcinoma (SDC) cohort, we aimed to investigate the clinical factors influencing their survival outcomes and to further establish prognostic models. METHODS: Data of patients with SDC were extracted from the Surveillance, Epidemiology, and End Results database (1975-2019). A retrospective analysis was conducted to explore the prognostic factors on overall survival (OS) and disease-specific survival (DSS), and corresponding nomograms were established. RESULTS: A steady upward trend in the incidence of SDC was observed over the past four decades. Totally, 399 patients (280 in the training set and 199 in the testing set) were enrolled. Advanced T stage, lymph node metastasis, distant metastasis, and surgery were associated with favorable OS and DSS. Besides, age > 80 years exhibited worse OS. The selected variables above were used to construct nomograms and online web calculators that could accurately predict patient survival. In addition, risk stratification systems were generated to identify low- and high-risk patients. As the risk level increased, the risk of both patient mortality and disease-specific mortality increased. CONCLUSIONS: The SDC incidence was low, but steadily increasing. The proposed prognostic models provided a robust and efficient approach to predict survival and risk stratification in SDC patients.

Transoral removal of submandibular hilar lithiasis: results on the salivary duct system, glandular parenchyma, and quality-of-life recovery.

OBJECTIVE(S): To confirm that hilar transoral submandibular sialolitectomy (TOSL) is the first treatment option for submandibular hilar lithiasis (SHL) in terms of glandular parenchyma recovery, salivary system restoration, and patient quality of life (QoL) improvement. METHODS: Depending on whether the stone was easily palpable, TOSL was carried out with or without sialendoscopy. For the first time in the literature, Magnetic Resonance Sialography (MR-Si) was performed before and after TOSL, to evaluate stone characteristics, glandular parenchyma status, hilum dilation and main duct recanalization. Radiological data was examined independently by two radiologists. COSQ, a recently validated and specific questionnaire, was used to assess associated QoL. RESULTS: Between 2017 and 2022, 29 TOSL patients were examined. With a high interobserver correlation, MR-Si was confirmed as a very useful radiological test in the pre- and post-surgical evaluation of SHL. The salivary main duct was completely recanalized in all cases. The presence of lithiasis was found in 4 patients (13.8%). After surgery, the majority of patients (79.31%) had hilum dilation. There was a statistically significant improvement in parenchyma status, but no significant progression to glandular atrophy. After surgery, COSQ mean values always improved (22.5 to 4.5). CONCLUSIONS: TOSL is the ideal surgical technique for the management of SHL, resulting in improved parenchymal inflammatory changes, recanalization of Wharton's duct, and enhancement patients' QoL. As a result, before removing the submandibular gland, TOSL should be considered as the first treatment option for SHL.

Periocular Mass Due to Persistent Secretion Within a Transplanted Parotid Duct.

A male patient underwent microvascular transplantation of an autologous submandibular gland and its associated (Wharton's) duct for management of very severe right keratoconjunctivitis sicca due to Stevens-Johnson syndrome; due to hypersecretion, the gland was later removed in toto. Twenty-two years later, he presented with a nontender, sausage-like mass lying subcutaneously in the right temple. Intraoperatively a fluctuant tubular mass passing from the temporalis fossa to the superotemporal conjunctiva was identified and excised intact. Histology showed a slightly proteinaceous fluid within a duct lined with cuboidal epithelium, this being compatible with Wharton's duct. This case highlights that iatrogenic causes should be considered with any history of periocular injury or surgery.

Peroxisomes Are Highly Abundant and Heterogeneous in Human Parotid Glands.

The parotid gland is one of the major salivary glands producing a serous secretion, and it plays an essential role in the digestive and immune systems. Knowledge of peroxisomes in the human parotid gland is minimal; furthermore, the peroxisomal compartment and its enzyme composition in the different cell types of the human parotid gland have never been subjected to a detailed investigation. Therefore, we performed a comprehensive analysis of peroxisomes in the human parotid gland's striated duct and acinar cells. We combined biochemical techniques with various light and electron microscopy techniques to determine the localization of parotid secretory proteins and different peroxisomal marker proteins in parotid gland tissue. Moreover, we analyzed the mRNA of numerous gene encoding proteins localized in peroxisomes using real-time quantitative PCR. The results confirm the presence of peroxisomes in all striated duct and acinar cells of the human parotid gland. Immunofluorescence analyses for various peroxisomal proteins showed a higher abundance and more intense staining in striated duct cells compared to acinar cells. Moreover, human parotid glands comprise high quantities of catalase and other antioxidative enzymes in discrete subcellular regions, suggesting their role in protection against oxidative stress. This study provides the first thorough description of parotid peroxisomes in different parotid cell types of healthy human tissue.

Outline of Salivary Gland Pathogenesis of Sjögren's Syndrome and Current Therapeutic Approaches.

Sjögren's syndrome (SS) is an autoimmune disease characterized by the involvement of exocrine glands such as the salivary and lacrimal glands. The minor salivary glands, from which tissue samples may be obtained, are important for the diagnosis, evaluation of therapeutic efficacy, and genetic analyses of SS. In the onset of SS, autoantigens derived from the salivary glands are recognized by antigen-presenting dendritic cells, leading to the activation of T and B cells, cytokine production, autoantibody production by plasma cells, the formation of ectopic germinal centers, and the destruction of salivary gland epithelial cells. A recent therapeutic approach with immune checkpoint inhibitors for malignant tumors enhances the anti-tumor activity of cytotoxic effector T cells, but also induces SS-like autoimmune disease as an adverse event. In the treatment of xerostomia, muscarinic agonists and salivary gland duct cleansing procedure, as well as sialendoscopy, are expected to ameliorate symptoms. Clinical trials on biological therapy to attenuate the hyperresponsiveness of B cells in SS patients with systemic organ involvement have progressed. The efficacy of treatment with mesenchymal stem cells and chimeric antigen receptor T cells for SS has also been investigated. In this review, we will provide an overview of the pathogenesis of salivary gland lesions and recent trends in therapeutic approaches for SS.

[Recent progress in the treatment of intractable sialolithiasis].

Sialolithiasis occurs in approximately 0.45% to 1.20% of the general population. The typical clinical symptom manifests as a painful swelling of the affected glands after a meal or upon salivary stimulation, which extremely affects the life quality of the patients. With the development of sialendoscopy and lithotripsy, most sialoliths can be successfully removed with preservation of the gland. However, sialoliths in the deep hilar-parenchymal submandibular ducts and impacted parotid stones located in the proximal ducts continue to pose great challenges. Our research center for salivary gland diseases (in Peking University School and Hospital of Stomatology) has used sialendoscopy for 17 years and treated >2 000 patients with salivary gland calculi. The success rate was approximately 92% for submandibular gland calculi and 95% for parotid calculi. A variety of minimally invasive surgical techniques have been applied and developed, which add substantial improvements in the treatment of refractory sialolithiasis. Further, the radiographic positioning criteria and treatment strategy are proposed for these intractable stones. Most of the hilar-parenchymal submandibular stones are successfully removed by a transoral approach, including transoral duct slitting and intraductal basket grasping, while a small portion of superficial stones can be removed by a mini-incision in submandibular area. Impacted stones located in the distal third of parotid gland ducts are removed via "peri-ostium incision", which is applied to avoid a cicatricial stenosis from a direct ostium incision. Impacted parotid stones located in the middle and proximal third of the Stensen's duct are removed via a direct mini-incision or a peri-auricular flap. A direct transcutaneous mini-incision is commonly performed under local anesthesia with an imperceptible scar, and is indicated for most of impacted stones located in the middle third, hilum and intraglandular ducts. By contrast, a peri-auricular flap is performed under general anesthesia with relatively larger operational injury of the gland parenchyma, and should be best reserved for deeper intraglandular stones. Laser lithotripsy has been applied in the treatment of sialolithiasis in the past decade, and holmium ∶YAG laser is reported to have the best therapeutic effects. During the past 3 years, our research group has performed laser lithotripsy for a few cases with intractable salivary stones. From our experiences, withdrawal of the endoscopic tip 0.5-1.0 cm away from the extremity of the laser fiber, consistent saline irrigation, and careful monitoring of gland swelling are of vital importance for avoidance of injuries of the ductal wall and the vulnerable endoscope lens during lithotripsy. Larger calculi require multiple treatment procedures. The risk of ductal stenosis can be alleviated by endoscopic dilation. In summary, appropriate use of various endoscopy-assisted lithotomy helps preserve the gland function in most of the patients with refractory sialolithiasis. Further studies are needed in the following aspects: Transcervical removal of intraglandular submandibular stones, intraductal laser lithotripsy of impacted parotid stones and deep submandibular stones, evaluation of long-term postoperative function of the affected gland, et al.

Myoepithelial Carcinoma Arising in a Salivary Duct Cyst of the Parotid Gland: Case Presentation.

Cystic lesions observed in parotid glands are relatively rare and comprise 2-5% of all parotid primaries. A salivary duct cyst (SDC) is a true cyst representing 10% of all salivary gland cysts. The risk of malignant transformation of SDC's epithelium is extremely rare. In the literature, only three cases of carcinoma ex SDC of the parotid gland are described. This report presents the first in the literature case of myoepithelial carcinoma (MECA) arising from a parotid SDC. A 75-year-old male patient was referred to the Department of Cranio-Maxillofacial Surgery of the Jagiellonian University in Cracow, Poland due to a cystic tumor arising from the right parotid gland. Superficial parotidectomy with facial nerve preservation was performed. Histological examination confirmed a rare case of MECA emerging from the SDC. The immunohistochemical profile of MECA ex SDC was presented. During 6 months of the follow-up, local recurrence or distant metastasis was not observed.