Spatio-temporal expression of Sox2+ progenitor cells regulates the regeneration of rat submandibular gland.

OBJECTIVE: Sox2 plays crucial roles in tissues homeostasis and regeneration. However, there are lack of a comprehensive examination of Sox2 expression and its functional role in submandibular gland regeneration. Therefore, we aimed to elucidate the impact of Sox2 on submandibular gland regeneration. MATERIALS AND METHODS: A Sprague-Dawley rat submandibular gland duct ligation/de-ligation regeneration model was conducted in this study. Sox2-shRNA vectors were retro-ductally administered into the submandibular gland to establish a stable Sox2 knockdown model. Conventional histopathological and molecular biological methods were used to investigate phenotypic changes. RESULTS: The submandibular gland normalized completely 28 days after ligature removal (following 7 days of duct ligation). AQP5 expression gradually increased after ligation removal until returning to normal levels. In submandibular gland regeneration, Sox2 re-expressed and co-expressed with AQP5+ acinar cells, and Sox2 expression peaked on day 14, recovered to normal on day 28, reproducing the developmental pattern. Sox2 knockdown hindered gland regeneration and induced irreversible fibrosis. The AQP5 expression was significantly lower than the contemporaneous solely ligated group, while the blue collagen deposition and the Vimentin expression increased prominently. The expression of CD68, IL-1ß, TNF-α and IL-17A increased significantly, and epithelial cells in the Sox2 knockdown group expressed higher levels of IL-17A. CONCLUSIONS: These findings highlight Sox2 as a crucial regulator of the acinar cell lineage. Sox2+ progenitor cells are pivotal for acinar cell maintenance, which is indispensable for submandibular gland regeneration. Collectively, our findings may help develop targeted interventions for enhancing tissue repair and preventing irreversible fibrosis in salivary gland disorders.

Intranodal palisaded myofibroblastoma in the submandibular gland region: a case report.

Intranodal palisaded myofibroblastoma (IPM) is a rare benign tumor of the lymph nodes, particularly in inguinal lymph nodes. IPM originating from the submandibular gland lymph nodes is rarely encountered in clinical practice. Herein, we report the case of a 31-year-old male patient with IPM of the submandibular gland region and describe in detail magnetic resonance imaging findings and pathology. Magnetic resonance imaging detected a heterogeneous lesion with a hypointense rim on T2-weighted imaging with specificity in the left submandibular gland region. This case report will contribute to the accumulation of experience in the diagnosis of this disease.

Immunohistochemical expression of the cation channel TRPC6 in the submandibular and lacrimal gland and in salivary gland tumors.

BACKGROUND: Canonical transient receptor potential channels play a crucial role in cancer cell proliferation. While TRPC6 subtype detection in submandibular glands and the relevance of some TRPC channels in this gland have been shown in animal models, its histological detection in human lacrimal and submandibular glands, as well as related tumors, lacks systematic study. Studying TRPC6 in humans could lead to new therapeutic options. This research aimed to immunohistochemically detect TRPC6 in human samples of physiological lacrimal and submandibular glands and of adenoid cystic carcinoma and mucoepidermoid carcinoma. METHODS: Seven fixed body donors and samples of six cancer patients were examined. The ten tissue samples collected from the submandibular and lacrimal glands were then processed into histological slides and stained with hematoxylin-eosin. Tumor samples were provided as sections. TRPC6 presence was determined by immunohistochemistry, which was performed by indirect detection with a primary TRPC6 antibody, a secondary HRP-conjugated antibody and the chromogen diaminobenzidine. RESULTS: Results confirm TRPC6 expression in all ten physiological gland samples: all samples showed a immunohistochemical signal with varying intensity. No significant gender-specific differences could be observed. TRPC6 was detected in four of six submandibular adenoid cystic carcinoma and the mucoepidermoid carcinoma samples, especially in tumor cells' cytoplasma and nuclei. Excretory ducts consistently showed TRPC6. Mucous tubules, their nuclei and the nuclei of adipocytes generally showed no signal while serous acini and their nuclei showed a weak TRPC6 signal. CONCLUSION: The discovery of TRPC6 in glandular tissue indicates a role in salivary gland function and calcium homeostasis is a basis for further research into its significance for tumor development in adenoid cystic carcinoma and mucoepidermoid carcinoma of salivary glands. TRPC6 could be used as a target for treatment of these tumors. However, the correlation between TRPC6 and submandibular and lacrimal gland diseases requires further exploration.

Spirulina platensis shields the submandibular gland from cadmium toxicity by bolstering antioxidant defenses and maintaining its structural integrity.

Cadmium (Cd), an element categorized as a non-essential transitional metal, has potential hazards to the health of both human beings and animals. Spirulina platensis (SP), a type of blue-green algae, possesses a high concentration of essential antioxidants. The present study aimed to explore the possible defensive role of SP against Cd-induced submandibular gland injury in rats by assessment of biomarkers related to both oxidative stress and inflammatory processes, which were further explored through histopathological examination of submandibular gland tissue. Consequently, the study included 32 mature rats, subdivided into four different groups as follows: control, SP, Cadmium chloride (CdCl2), and CdCl2/SP. The duration of the study was 24days. The results revealed that CdCl2 induced submandibular gland injury as shown by the oxidant/antioxidant imbalance and increased inflammatory reactions, in addition to, histopathological changes and overexpression of BAX immunostaining. Concurrent SP administration to CdCl2-treated rats significantly improved all these effects. We concluded that concurrent SP supplement improved the submandibular gland injury provoked by CdCl2.

[Clinical application of retroauricular hairline approach in submandibular gland resection assisted by endoscope].

Objective:To investigate the clinical effect of retroauricular hairline approach in submandibular gland resection assisted by endoscope. Methods:A total of 18 patients with submandibular gland benign tumors treated in our hospital from September 2022 to September 2023 were selected. A 5 cm incision was designed in the retroauricular hairline, and the flap was turned over directly to the anterior edge of sternocleidomastoid muscle, then the flap was turned over to build the cavity through endoscopic surgery, and submandibular gland resection was completed with the assistance of endoscope. After operation, a negative pressure drainage was placed into the hairline, and the wound was closed by continuous intracutaneous suture. The clinical effect was evaluated after 3-6 months follow-up. Results:All patients underwent submandibular gland resection with endoscopic assistance as planned, and none of them converted to submaxillary incision during operation. The operation time was 65-97 min, with an average of 75 min. Intraoperative bleeding was 10-20 mL, with an average of 14 mL.No tongue numbness, wound infection, or tumor recurrence occurred after operation. However, there were 10 patients with ear numbness and discomfort of auricle after surgery, which gradually recovered after 6-9 months of follow-up. Two patients had crooked mouth after surgery, and the symptoms were gradually relieved after follow-up. All incisions healed in stage I and were concealed. Conclusion:Endoscopic retroauricular hairline approach is a choice for submandibular gland resection with good cosmetic effect, less trauma and fewer complications.

Acute upper airway obstruction caused by mouth floor cellulitis in a patient of advanced age: a case report and literature review.

Mouth floor cellulitis is a type of diffuse cellulitis involving the submandibular, submental, and sublingual spaces. This condition may cause asphyxia due to elevation and posterior deviation of the tissues of the floor of the mouth. The severity of submandibular gland infection often escalates in the presence of underlying comorbidities. Advanced age, hyperglycemia, and an immunocompromised status often lead to the rapid development of infection, resulting in complications such as acute upper airway obstruction. These complications increase treatment difficulty and the risk of mortality. We herein report a case involving an older adult with diabetes who developed mouth floor cellulitis secondary to a submandibular gland infection. Despite the severity of the submandibular gland infection, a timely, effective, and multidisciplinary approach improved the patient's prognosis.

Decellularization of Rat Submandibular Gland for Salivary Gland Tissue-Engineering Applications.

OBJECTIVES: This study describes a robust and versatile method for decellularization of rat submandibular glands (SMGs). METHODS: Briefly, rat SMGs were harvested and subjected to perfusion cycles using an anionic detergent. Native and decellularized SMG tissues were subjected to histological analysis using hematoxylin and eosin (H&E) stain and immunohistochemical staining using Hoescht reagent. Further, complementary DNA was synthesized using the native and decellularized SMG tissues and subjected to quantitative reverse transcription polymerase chain reaction (RT-PCR) using rat-specific genes (i.e., α-amylase [Amyl], aquaporin 5 [Aqp5], mucin 19 [Muc19] and glyceraldehyde-3-phosphate dehydrogenase [GAPDH]). The total DNA within native and decellularized SMG tissues were also quantified. RESULTS: H&E staining of SMG tissues revealed preserved ECM content. Decellularized SMG scaffolds lacked cellular material but retained collagen bundles similar to native SMGs. Hoechst reagent immunostaining showed cell nuclei and DNA present in native SMG but not in decellularized SMG scaffolds. Quantitative RT-PCR analysis showed specific amplification products of salivary gland-specific genes (Amyl, Muc19 and Aqp5) and GAPDH in the native SMG tissues. However, no amplification product was observed in the cDNAs from the decellularized SMG scaffolds, confirming the absence of DNA. Quantification of the DNA content showed that the decellularized SMG scaffolds had significantly lower DNA content than native SMG tissue. CONCLUSIONS: Results from this study demonstrated that the decellularization protocol was effective in removing cellular material while preserving the extracellular matrix components and structural integrity of the native SMG tissue.

Risk stratification of submandibular salivary gland involvement in oral squamous cell carcinoma based on histopathological parameters: A 15-year retrospective study.

Objective: Squamous cell carcinoma (SCC) represents about 90% of all oral malignancies. The study aimed to assess the involvement of the submandibular salivary gland (SMG) in oral SCC (OSCC) patients and the need for SMG excision. Materials and Methods: Demographics, clinical information and staging of the 210 patients undergoing surgery for OSCC were obtained from the department records. The histopathological slides were retrospectively reviewed. The nodal status was also verified with the histopathology reports. Frequency distribution, Chi-square association, ordinal logistic regression analysis and Kaplan-Meier analysis were performed. Results: SMG was excised in 171 patients. Five patients had SMG involvement. Buccal mucosa (BM) and gingivobuccal sulcus had a greater risk of level IB metastases (P < 0.01). Pattern 3 and pattern 4 of invasion had a higher risk of level IB metastases (P = 0.04). Depth of invasion (DOI) >4 mm was associated with level IB lymph node (LN) involvement (P = 0.0001). DOI >4 mm to 8 mm had 3.7 times the risk and a DOI >8 mm to 12 mm had 5 times the risk of level IB metastases. Pattern of invasion (POI), tumour budding and DOI >4 mm were significant prognosticators for patient survival. Conclusion: Histologically, patients may be categorised as 'high risk': those with an increased risk of level IB LN involvement and 'low risk': those at low risk for level IB involvement with the help of POI, tumour budding and DOI as risk factors. In low-risk patients, SMG may be spared and the level IB LNs are dissected. High-risk patients may be chosen as candidates for SMG transfer or excision based on the extent of LN involvement.

Submandibular and sublingual salivary gland involvement in adenoid cystic carcinoma.

Adenoid cystic carcinoma (AdCC) is a malignant salivary gland neoplasm that presents as an indolent but aggressive neoplasm. AdCC histogenesis is linked to the intercalated ducts of the salivary glands, equally affecting the major and minor glands. AdCC is associated with distant metastasis, most commonly to the lungs, and a high recurrence rate. AdCC accounts for 4.2% of all tumors. About 55% of all reported cases affect the submandibular gland, and around 50% of AdCC cases occur in the minor salivary glands. The present review describes a case of AdCC which presented a single nodular swelling on the right side involving the floor of the mouth. It also consolidates the histopathological profile of a case of AdCC with all the relevant histopathological features.

Early Clinical Mapping of Submandibular Gland Fistula: A Case Report and Systematic Review.

Introduction Submandibular gland fistula (SGF) is a rare subset of salivary gland fistulas. It is seldom tough to diagnose them prior to surgical exploration, and it is often clinically confused with close differentials. An early diagnosis based on pertinent clinical features and focused radiological findings can be pivotal in optimal management and help prevent recurrence and avoid unnecessary investigations/interventions. Objective To review articles that discuss SGF and provide vital etiological, clinical, and imaging features of this rare entity that can aid in early clinical diagnosis. Data Synthesis An extensive review involving PubMed and Google Scholar and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. Conclusion Submandibular gland fistula is a rare entity. It can be confused with close differentials, including branchial fistulas, if not thoroughly examined. Discharge from fistulae along with submandibular pain/tenderness and/or swelling are important diagnostic clues. A history of trauma, nodule at the site of discharge, prior submandibular disease/calculi, or discharge aggravated with food further increases a clinical suspicion. Optimal radiological investigation looking for calculi/foreign body and delineating the fistula tract is vital to affirm a diagnosis. Gland with fistula excision is a commonly advocated treatment of choice with no reports of recurrence, although conservative management and gland preserving surgery have also reported a favorable prognosis.

Uncommon Site Presentation: A Case Report of Extraparotid Warthin's Tumor.

Warthin's tumor, also known as adenolymphoma or papillary cystadenoma lymphomatosum, is a benign tumor almost exclusively found in the parotid gland and is the second most common type of benign parotid tumor. Its manifestation as an extraparotid lesion is rare, with a low incidence in the submandibular gland. In this context, we present a case of Warthin's tumor of the submandibular gland in a 66-year-old man who presented with a painless lateral cystic cervical mass. This case highlights the clinical and radiological evidence of an uncommon extraparotid tumor location, with the diagnosis becoming evident only after the enucleation of the mass. Despite the rarity of extraparotid Warthin's tumor and its potential variation in location, the authors recommend considering Warthin's tumor of the submandibular gland in the differential when assessing lateral cervical masses.

Toll-like receptors 2 and 4, and bacterial proteins in IgG4-related sialadenitis, other types of chronic sialadenitis and sialolithiasis.

Background: The association of chronic sclerosing sialadenitis and IgG4-related disease (IgG4-RD) has resulted in the more frequent identification of IgG4-positivity in submandibular gland inflammations, also uncovering IgG4 overexpression in nonspecific inflammations. These findings lead us to hypothesise that IgG4-positive sialadenitis represents a continuous inflammatory process overlapping histologically with IgG4-RD, possibly differing in aetiology. However, the antigen underlying IgG4 overexpression in IgG4-positive sialadenitis and IgG4-RD remains unknown. Materials and methods: Here, we investigated toll-like receptor (TLR) - mediated bacterial inflammation in submandibular gland tissues of patients with IgG4-positive and IgG4-negative chronic inflammatory lesions of the submandibular gland (n = 61), with noninflamed submandibular glands serving as controls (n = 4). Utilising immunohistochemistry, we assessed the expression of TLR2 and TLR4, lipopolysaccharide (LPS) and the P. gingivalis-specific antigen gingipain R1. Results: We observed TLR2- and TLR4-immunopositivity in 64 (98%) samples. However, TLR2 and TLR4 staining intensity was significantly stronger in the IgG4-positive group. LPS- and gingipain R1 immunopositivity were observed in 56 (86%) and 58 (89%) samples, respectively. LPS-positivity localised exclusively in mast cell-like cells, while gingipain R1-positivity remained scarce. Conclusions: A stronger TLR2 or TLR4 expression in IgG4-positive sialadenitis may indicate a tissue-related factor underlying this form of chronic sialadenitis. LPS- and P. gingivalis immunopositivity remained weak throughout this series. Thus, gram-negative bacteria may not represent pathogens underlying these forms of chronic sialadenitis.

Tert-expressing cells contribute to salivary gland homeostasis and tissue regeneration after radiation therapy.

Salivary gland homeostasis and regeneration after radiotherapy depend significantly on progenitor cells. However, the lineage of submandibular gland (SMG) progenitor cells remains less defined compared with other normal organs. Here, using a mouse strain expressing regulated CreERT2 recombinase from the endogenous Tert locus, we identify a distinct telomerase-expressing (TertHigh) cell population located in the ductal region of the adult SMG. These TertHigh cells contribute to ductal cell generation during SMG homeostasis and to both ductal and acinar cell renewal 1 year after radiotherapy. TertHigh cells maintain self-renewal capacity during in vitro culture, exhibit resistance to radiation damage, and demonstrate enhanced proliferative activity after radiation exposure. Similarly, primary human SMG cells with high Tert expression display enhanced cell survival after radiotherapy, and CRISPR-activated Tert in human SMG spheres increases proliferation after radiation. RNA sequencing reveals upregulation of "cell cycling" and "oxidative stress response" pathways in TertHigh cells following radiation. Mechanistically, Tert appears to modulate cell survival through ROS levels in SMG spheres following radiation damage. Our findings highlight the significance of TertHigh cells in salivary gland biology, providing insights into their response to radiotherapy and into their use as a potential target for enhancing salivary gland regeneration after radiotherapy.

Primary Epithelioid Angiosarcoma of the Submandibular Gland-A Case Report with Histology-Cytology Correlation and Comprehensive Molecular Analysis.

BACKGROUND: Angiosarcoma is a sarcoma that occurs in a range of tissue types, and only rarely in the salivary glands, showing a predilection for the parotid glands of older patients. Preoperative diagnosis may be challenging, especially on cytology, with significant morphological overlap with high-grade primary salivary gland carcinomas. The molecular alterations of this rare salivary gland neoplasm are also not well-characterized. METHODS AND RESULTS: We present a case of right submandibular gland swelling in a 73-year-old male. On fine needle aspiration, including immunohistochemical stains on cell block, the tumor was initially diagnosed as poorly differentiated carcinoma. Resection of the submandibular gland revealed epithelioid angiosarcoma. We performed molecular work-up of the tumor, utilizing targeted next-generation sequencing, DNA methylation profiling and fluorescence in-situ hybridization. Histopathologic assessment revealed an infiltrative tumor comprising solid sheets of epithelioid cells. The tumor cells formed haphazardly anastomosing vascular channels with intracytoplasmic lumina containing red blood cells. On immunohistochemistry, the tumor cells were positive for CD31, CD34 and ERG. Approximately 40% of the tumor cells showed nuclear expression of GATA3. A pathogenic TP53 R267W mutation was detected on next-generation sequencing. DNA methylation analysis did not cluster the tumor with any known sarcoma type. Copy number analysis showed possible MYC amplification and CDKN2A losses, although only the latter was confirmed on fluorescence in-situ hybridization. CONCLUSION: Epithelioid angiosarcoma is an important differential diagnosis to high-grade salivary gland carcinoma. In particular, GATA3 expression may be encountered in both angiosarcoma and high-grade salivary gland carcinomas and cause diagnostic confusion. Identification of TP53 mutations and CDKN2A losses suggest shared oncogenic pathways with soft tissue angiosarcomas, and should be further investigated.

Solitary Submandibular Schwannoma Mimicking a Salivary Gland Tumor in a Child.

Tumors occurring in the submandibular space are infrequent among pediatric patients, and benign peripheral nerve tumors in this region are exceptionally rare. This study describes the uncommon occurrence of a schwannoma in the submandibular space in a child and describes its management. A 7-year-old child presented with a gradually enlarging swelling over a 7-month period in the submandibular region, clinically resembling a salivary gland tumor. There were no associated marginal mandibular, lingual, or hypoglossal nerve palsy. The mass was excised completely, and histopathological examination revealed it to be a schwannoma. It is appropriate to consider benign peripheral nerve tumors, such as schwannoma, in the differential diagnosis of submandibular space tumors in children.

Novel decision tree models predict the overall survival of patients with submandibular gland cancer.

BACKGROUND: While the accurate prediction of the overall survival (OS) in patients with submandibular gland cancer (SGC) is paramount for informed therapeutic planning, the development of reliable survival prediction models has been hindered by the rarity of SGC cases. The purpose of this study is to identify key prognostic factors for OS in SGC patients using a large database and construct decision tree models to aid the prediction of survival probabilities in 12, 24, 60 and 120 months. MATERIALS AND METHODS: We performed a retrospective cohort study using the Surveillance, Epidemiology and End Result (SEER) program. Demographic and peri-operative predictor variables were identified. The outcome variables overall survival at 12-, 24-, 60, and 120 months. The C5.0 algorithm was utilized to establish the dichotomous decision tree models, with the depth of tree limited within 4 layers. To evaluate the performances of the novel models, the receiver operator characteristic (ROC) curves were generated, and the metrics such as accuracy rate, and area under ROC curve (AUC) were calculated. RESULTS: A total of 1,705, 1,666, 1,543, and 1,413 SGC patients with a follow up of 12, 24, 60 and 120 months and exact survival status were identified from the SEER database. Predictor variables of age, sex, surgery, radiation, chemotherapy, tumor histology, summary stage, metastasis to distant lymph node, and marital status exerted substantial influence on overall survival. Decision tree models were then developed, incorporating these vital prognostic indicators. Favorable consistency was presented between the predicted and actual survival statuses. For the training dataset, the accuracy rates for the 12-, 24-, 60- and 120-month survival models were 0.866, 0.767, 0.737 and 0.797. Correspondingly, the AUC values were 0.841, 0.756, 0.725, and 0.774 for the same time points. CONCLUSIONS: Based on the most important predictor variables identified using the large, SEER database, decision tree models were established that predict OS of SGC patients. The models offer a more exhaustive evaluation of mortality risk and may lead to more personalized treatment strategies.

Pediatric Salivary Gland Pathology.

Benign and malignant salivary gland disorders are uncommon in the pediatric population; however, these can be frequently seen in pediatric otolaryngology or oral and maxillofacial surgery practices. The astute clinician should be aware of the clinical presentation, diagnosis, and management options for common inflammatory, infectious, benign, and malignant disorders of salivary glands.

P2X7R and P2X4R expression of mice submandibular gland in high-fat diet/streptozotocin-induced type 2 diabetes.

Type 2 diabetes mellitus (T2DM) is a chronic inflammatory disease that can compromise the functioning of various organs, including the salivary glands (SG). The purinergic system is one of the most important inflammatory pathways in T2DM condition, and P2X7R and P2X4R are the primary purinergic receptors in SG that regulate inflammatory homeostasis. This study aimed to evaluate P2X7R and P2X4R expression, and morphological changes in the submandibular gland (SMG) in T2DM. Twenty-four 5-week-old mice were randomly assigned to control (CON) and diabetes mellitus (DM) groups (n = 12 each). Body weight, diet, and blood glucose levels were monitored weekly. The histomorphology of the SMG and the expression of the P2X7R, and P2X7R was evaluated by immunohistochemistry (IHC) staining and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) at 11 and 13 weeks of age. Our findings indicate a significant increase in food consumption, body weight, and blood glucose levels in the DM group. Although a significant increase in P2X7R and P2X4R expression was observed in the DM groups, the receptor location remained unchanged. We also observed a significant increase in the acinar area in the DM13w group, and a significant decrease in the ductal area in the DM11w and DM13w groups. Targeting purinergic receptors may offer novel therapeutic methods for diabetic complications.

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.