Mucoepidermoid carcinoma. An update and review of the literature

Exploring the Landscape of Salivary Gland Disorders: A Comprehensive Bibliometric Analysis

Objective

This study aims to conduct a major bibliometric analysis of salivary gland disorders, exploring publication characteristics, trends, and influential contributors. The primary objective is to improve understanding of the current state of research in this area and to identify potential directions for future investigation.

Methods

A comprehensive study was conducted analysing 11,679 publications from 1980 to 2023 retrieved from the Web of Science Core Collection. The analysis included collaboration across countries, keyword co-occurrence, co-citation networks and clustering. CiteSpace and VOSviewer were used to explore relationships and create visualisations.

Results

The analysis revealed a dynamic landscape of salivary gland research, with the United States leading in both the number of publications (n = 2998) and centrality (0.26). Network analysis unveiled nine clusters, including topics such as parotidectomy and immunohistochemistry. Co-occurrence analysis of keywords highlighted evolving trends, with recent emphasis on terms such as sialendoscopy, cytopathology, and gene fusion. The timeline view illustrated the changing significance of terms over the years, reflecting current areas of interest such as radiomics and mucoepidermoid carcinoma.

Conclusion

This study provides a comprehensive overview of the field, offering insights into influential work, collaborative networks, and emerging trends. The outputs of the analysis can guide researchers and clinicians in shaping future investigations.

Mucoepidermoid carcinoma lacking squamous component arising in rare location: utility of MAML2 genetic testing for diagnosis

Salivary gland malignancies are rare, accounting for less than 5% of head and neck cancers. Mucoepidermoid carcinoma (MEC) is the most common salivary gland tumour, predominantly found in the parotid gland. However, it has rarely been reported in the tongue. Histologically, these tumours typically exhibit a combination of mucous, squamous and intermediate cell components. In the 2022 version of the WHO classification of salivary gland tumours, MAML2 rearrangement is desirable but not essential for diagnosis. In rare cases, MEC may lack a squamous component, posing diagnostic challenges. In such cases, MAML2 rearrangement is crucial for diagnosis. We present a unique case of a man in his 60s with a MEC arising in the tongue with predominantly clear cells and devoid of squamous components. This case emphasises the critical role of MAML2 genetic testing in achieving an accurate diagnosis in rare locations with unusual morphology.

Predictors of recurrence and survival after salivary gland cancer surgery: A multicenter, retrospective study in northern Japan

OBJECTIVES

Salivary gland cancer is a rare disease composed of more than 20 histological types with different grades of malignancy. The aim of this multicenter, retrospective study was to identify the most important predictors affecting recurrence and survival after surgery.

MATERIAL AND METHODS

A total of 543 patients with salivary gland cancers that underwent curative surgery between 2012 and 2022 in 13 institutions in northern Japan were evaluated in this study. Predictors affecting recurrence and survival were identified by univariate and multivariate Cox regression analyses. Age, sex, primary site, histological type, pathological T status, surgical margin, lymph node metastasis, extranodal extension, and postoperative radiotherapy were the variables evaluated.

RESULTS

Multivariate Cox regression analysis showed that increasing age, submandibular cancer, pathological T status 3 or 4, positive surgical margin, and lymph node metastasis, especially with extranodal extension, were independent risk factors for both recurrence and survival. Sublingual cancer was an independent risk factor for recurrence. Postoperative radiotherapy was associated with a lower risk of recurrence and a good prognosis, and adenoid cystic carcinoma was associated with a good prognosis.

CONCLUSION

Lymph node metastasis with extranodal extension was the most important prognostic factor affecting both recurrence and survival after surgery, adenoid cystic carcinoma was associated with a good prognosis, and postoperative radiotherapy was associated with a lower risk of recurrence and a good prognosis.

The Immunoexpression and Prognostic Significance of Stem Cell Markers in Malignant Salivary Gland Tumors: A Systematic Review and Meta-Analysis

Background/Objectives: Salivary gland carcinomas encompass a broad group of malignant lesions characterized by varied prognoses. Stem cells have been associated with the potential for self-renewal and differentiation to various subpopulations, resulting in histopathological variability and diverse biological behavior, features that characterize salivary gland carcinomas. This study aims to provide a thorough systematic review of immunohistochemical studies regarding the expression and prognostic significance of stem cell markers between different malignant salivary gland tumors (MSGTs). Methods: The English literature was searched via the databases MEDLINE/PubMed, EMBASE via OVID, Web of Science, Scopus, and CINHAL via EBSCO. The Joanna Briggs Institute Critical Appraisal Tool was used for risk of bias (RoB) assessment. Meta-analysis was conducted for markers evaluated in the same pair of diseases in at least two studies. Results: Fifty-four studies reported the expression of stem cell markers, e.g., c-KIT, CD44, CD133, CD24, ALDH1, BMI1, SOX2, OCT4, and NANOG, in various MSGTs. Low, moderate, and high RoB was observed in twenty-five, eleven, and eighteen studies, respectively. Meta-analysis revealed an outstanding discriminative ability of c-KIT for adenoid cystic carcinoma (AdCC) over polymorphous adenocarcinoma [P(LG)A] but did not confirm the prognostic significance of stem cell markers in MSGTs. Conclusions: This study indicated a possible link between stem cells and the histopathological heterogeneity and diverse biological behavior that characterize the MSGTs. c-KIT might be of diagnostic value in discriminating between AdCC and P(LG)A.

Mucoepidermoid carcinoma: Enhancing diagnostic accuracy and treatment strategy through machine learning models and web-based prognostic tool

BACKGROUND

Oral cancer, particularly mucoepidermoid carcinoma (MEC), presents diagnostic challenges due to its histological diversity and rarity. This study aimed to develop machine learning (ML) models to predict survival outcomes for MEC patients and pioneer a clinically accessible prognostic tool.

METHODS

Using the SEER database (2000-2020), we constructed predictive models with five ML algorithms: Random Forest Classifier (RFC), Gradient Boosting Classifier (GBC), Logistic Regression (LR), K-Nearest Neighbors (KNN), and Multilayer Perceptron (MLP). Predictive variables were identified via Cox regression, and Kaplan-Meier analysis assessed survival trends. Model performance was validated through the area under the curve (AUC) of receiver operating characteristic (ROC) curves.

RESULTS

This study included 1314 patients diagnosed with MEC of the oral cavity. The RFC demonstrated the highest predictive accuracy (AUC = 0.55), followed by the GBC and RFC (AUC = 0.53). The most affected primary site was the hard palate, followed by the retromolar and cheek mucosa. Survival rates varied with the treatment modality, with the highest rates observed in patients undergoing surgery alone. ML models have identified age, sex, and metastasis as significant prognostic factors influencing survival outcomes, underscoring the complexity and heterogeneity of MEC.

CONCLUSIONS

This study highlights ML's potential to enhance survival predictions and personalize treatment for MEC patients. We developed the first web-based prognostic tool, providing a novel, accessible solution for improving clinical decision-making in MEC.

Active Surveillance for Pleomorphic Adenomas of the Parotid-Tumor Growth Rate, Potential Malignancy, and Surgical Sequalae

OBJECTIVE

The outcomes of active surveillance (AS) for pleomorphic adenomas (PA) as an alternative to upfront parotidectomy have not been previously documented in the literature. This cohort study aims to assess the safety and feasibility of AS for parotid gland PA.

METHODS

All patients with of previously untreated PA managed between 1990 and 2015 were reviewed. Patients who underwent AS for a minimum of 1 year from the initial consultation were identified. Patient demographics, the reason for AS, tumor growth rate, indication for surgery in those patients eventually operated, final pathology, and surgical sequelae were analyzed.

RESULTS

During the study period, 610 patients with primary PA were treated in our institution. Of whom, 14 (2.3%) underwent AS for a period between 1 and 10 years with a median of 3.73 years (interquartile range [IQR] 1.3-4.9). Patient comorbidities were the most common reason for opting for AS (n = 6, 43%), followed by patients' preference to delay surgery (n = 4, 29%) and older age (n = 2, 14%). The median growth rate was 0.58 mm/year (IQR 0.04, 3.8, range -5.01 to 4.98 mm/year). In patients who eventually underwent parotidectomy (n = 10, 71.4%), the most common reason for intervention was tumor growth (8/10, 80%). Two patients had postsurgical mild transient facial nerve paresis with full recovery, and no carcinomas were discovered on final pathology.

CONCLUSION

In this selected cohort of patients with PA, the tumor growth rate was lower than traditionally believed. Patients who eventually underwent surgery did not suffer from serious complications and there was no evidence of clinical or pathological malignancy.

MAML2-rearrranged sclerosing mucoepidermoid carcinoma of submandibular gland: an incidental finding in a patient with history of recurrent sialadenitis and Sjögren's syndrome

The Sclerosing subtype of mucoepidermoid carcinoma is rare, with only 39 cases reported in literature. We present a new case of sclerosing mucoepidermoid carcinoma (SMEC) with MAML2 rearrangements. A 49-year-old woman with Sjögren's syndrome experienced recurrent submandibular sialadenitis and sialolithiasis, leading to the removal of her right gland. Postoperative imaging revealed a calcified mass in her left gland which was subsequently resected. The pathologic examination revealed a well-defined tumor with extensive fibrous stroma, predominantly epidermoid cells, and occasional mucinous components. There was a dense lymphocytic and plasma cell infiltrate at the tumor's periphery. Immunohistochemistry was positive for p40 and CK7, few IgG4+ plasma cells. No eosinophils were identified. Fluorescence in situ hybridization (FISH) revealed rearrangement of the MAML2 (11q21) region. Adjuvant radiation was not recommended because of the patient's history of autoimmune diseases and the fact that the tumor was small, localized, and had negative resection margins. The patient was advised to undergo a repeat CT scan of the neck, scheduled for 3 months later. This case highlights the importance of considering SMEC in the differential diagnosis of patients with sialolithiasis or Sjögren's syndrome.

Primary intraosseous squamous cell carcinoma originating from a mandibular odontogenic cyst: A case report

Malignant transformation arising in the background of jaw cysts is a rare and often misdiagnosed condition, particularly when developing from residual root-derived cysts. We present a case of epithelial malignancy originating from a residual root-derived cyst in the mandible of a man around 50 years old. Histological evaluation of the sections revealed that the epithelial lining of the cystic lesion contained well-differentiated squamous cell carcinoma components. Finally, a segmental mandibulectomy was performed, and the defect was reconstructed with free iliac bone grafting. This case underscores the critical role of chronic inflammation in the malignant transformation of mandibular cysts and enriches the current database on odontogenic cyst malignancy.

Neck Dissection in cT3/T4 Mucoepidermoid Carcinoma of the Oral Cavity and Oropharynx

Previous research has reported high occult nodal metastases rates for T3/T4 mucoepidermoid carcinoma (MEC) of the oropharynx (OP) and oral cavity (OC). Our study evaluates if there is a benefit of neck dissection (ND) in these patients. The 2004-2016 National Cancer Database was queried for cases of adult MEC of the OC and OP. Patients with clinical T3/T4 disease were included while those with metastatic disease were excluded. Patients were divided into two cohorts: those treated with and without ND. Univariate chi-square, Kaplan-Meier, and multivariable Cox regression analyses were implemented. A total of 243 patients met inclusion criteria, of which 79 (32.5%) underwent ND. The majority of patients were less than 60 years old (60.1%), White (76.2%), and male (53.5%). 92 (37.9%) patients had clinically node-positive (cN+) disease. ND patients had higher rates of cN + disease (53.2% vs. 30.5%, p = 0.002). Of patients undergoing ND, 35 (44.3%) had cN0 disease while 42 (53.2%) had cN + disease. ND patients more commonly had grade III/IV tumors (45.1% vs. 23.4%, p = 0.002). Upon examination of dissected nodes, 20.3% of cN0 patients undergoing ND were found to have occult nodal metastases. There was no significant difference in 5-year overall survival between patients with and without ND (61.8% vs. 53.6%, p = 0.610), even on multivariable Cox analysis (hazard ratio: 1.52, 95% confidence interval: 0.73-3.18, p = 0.269). Our study found patients with cN0 MEC of the OC and OP have a high rate (20.3%) of occult nodal metastasis. In this cohort, patients with ND were not found to have improved survival, possibly due to statistical underpowering. Further research is needed to evaluate the indications and benefit of ND for this rare tumor presentation.

Managing malignant sublingual gland tumors: a single institution experience with 23 patients

BACKGROUND

Due to the relative rarity of malignant sublingual gland tumors, diagnosing and treating them clinically pose challenges. Hence, there's a need to explore the pathological types, characteristics, treatment methods, and prognosis of primary malignant tumors of the sublingual gland to improve our understanding and management of these rare yet highly malignant conditions.

METHODS

This study reviewed cases of primary malignant sublingual gland tumors, analyzing their characteristics. The treatment methods included surgical excision, with additional radiotherapy, or brachytherapy for advanced stages or positive surgical margins. The study also summarized different treatment approaches, including lymph node dissection and soft tissue reconstruction using free flaps such as the anterolateral thigh flap and forearm flap.

RESULTS

We have gathered 23 cases of sublingual gland malignancies treated at the Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, from January 2013 to May 2024. The most common pathological types were adenoid cystic carcinoma and mucoepidermoid carcinoma, with rare cases of mucosa-associated lymphoid tissue (MALT) lymphoma and nonspecific salivary gland clear cell carcinoma. Early diagnosis and surgical intervention were crucial for a favorable prognosis. Marginal mandibulectomy was necessary for cases involving the mandible. Patients with positive preoperative lymph node detection required cervical lymph node dissection. Extensive tissue defects in the floor of the mouth were effectively reconstructed with free flaps to prevent oral-mandibular fistula.

CONCLUSION

Surgical excision remains the preferred treatment for malignant sublingual gland tumors. Early diagnosis and comprehensive surgical management are essential for improving prognosis. The study's limitations include a small sample size and short follow-up duration, necessitating further research with larger clinical samples to confirm these findings.

Epidemiology, prognostic factors, and treatment of head and neck mucoepidermoid carcinoma: Analysis of the surveillance, epidemiology, and end results database

OBJECTIVES

To investigate prognostic factors in patients with head and neck Mucoepidermoid Carcinoma (MEC), especially the impact of treatment modalities on survival.

METHODS

Patients with primary head and neck MEC between 2000 and 2015 were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Prognostic factors related to Overall Survival (OS) and Cancer-Specific Survival (CSS), as well as the impact of treatments, were evaluated by multivariable Cox regression analysis.

RESULTS

We identified 2692 patients diagnosed with head and neck MEC, of whom 1397 (51.89%) had a parotid gland primary, 569 (22.14%) died, and 341 (12.67%) died of MEC. Older age (≥53 years), males, unmarried, lower income, tumor site in other head and neck areas, higher tumor grade, larger tumor size, and higher stage were related to poorer OS and CSS. Patients who did not undergo surgery (HR=3.20, 95% CI 2.45‒4.18) had worse OS, while no significant difference was detected between partial and total organ excision on patients' OS (p=0.729). For combination therapy, patients who received radiotherapy only (HR=3.21, 95% CI 2.27-4.53) or no surgery and no radiotherapy (HR=2.59, 95% CI 1.83-3.67) were correlated with worse OS (vs. surgery only), but no significant difference was detected between surgery only and surgery combined with radiotherapy on patients' OS (p=0.218). For CSS, the corresponding results were consistent with OS.

CONCLUSION

Surgical resection only may be a better survival option for head and neck MEC.

Adolescent tongue base tumour with diagnostic histopathological dilemma

Mucoepidermoid carcinoma arising from minor salivary glands at the base of the tongue is rare. Surgical excision of the tumours remains the primary treatment of choice. The prognosis of this tumour depends on optimum clearance of the disease surgically, clinical staging and histopathological grading. Postoperatively, radiotherapy depends on the grading and histopathological features of the tumour. Long-term follow-up is a must to detect early recurrences of oropharyngeal tumours. In our case, the tumour was removed by the transoral route because it was a limited tumour and for better postoperative functional outcomes. Concurrent chemoradiotherapy was advised to address the perineural invasion and residual tumour of the base of the tongue region.

Unusual Presentation of a Parotid Gland Malignancy: A Case Report

The most commonly occurring malignant salivary gland tumor is mucoepidermoid carcinoma (MEC). It consists of intermediate cells, squamous cells, and mucous-secreting cells. It is usually not capsulated and is identified by mucocarmine staining. Mucoepidermoid carcinoma exists in the thyroid gland and lungs as well. This report presents a case of a very rare sclerosing variant of MEC of the parotid gland in a 48-year-old patient. The patient presented with a small swelling below the left earlobe. Ultrasound-guided fine-needle aspiration cytology (FNAC) was carried out. A diagnosis of pleomorphic adenoma was given. The patient underwent a partial parotidectomy under general anesthesia. The final diagnosis was made through histopathological examination after the surgical removal of the tumor. The patient is now under close follow-up to look out for a recurrence. This case highlights the importance of recognizing and managing rare variants of MEC to optimize patient outcomes.

Parotid Gland Tumors: Molecular Diagnostic Approaches

Parotid gland pathology represents a web of differential diagnoses. There are many complex cases that require extensive diagnostic tests for a complete and correct final pathology diagnosis. Currently the official classification of parotid gland tumors extends over more than 40 subtypes. We performed a query of the PubMed database regarding the use of molecular biology tests in performing a better characterization of the tumors in specific cases. By using fluorescence in situ hybridization (FISH), reverse transcription polymerase chain reaction (RT-PCR) or next-generation sequencing, the team managing complex cases can offer a personalized therapeutic solution. We review the molecular differential diagnosis according to published articles in the last 5 years for many types of parotid gland tumors ranging from benign to borderline malign tumors to malign aggressive tumors. Mucoepidermoid carcinoma is a distinct subtype of parotid malignancy that was the subject of a consistent number of articles. However, the molecular biology diagnosis techniques helped more in excluding the diagnosis of mucoepidermoid carcinoma, and probably retrospectively limiting the number of cases with this final diagnosis. In Romania, the molecular biology diagnosis is available only in limited research facilities and should receive more consistent funding that will make it available on a larger scale. The novelty of this scoping review is that we propose an algorithm for molecular differential diagnosis of the tumors that could be encountered in the parotid gland.

Tumor budding - a potential biomarker in low grade salivary gland carcinomas?

Background

Low-grade salivary gland carcinoma is regularly treated with surgical therapy of the salivary gland without elective neck dissection in T1/2 carcinomas, either alone or with adjuvant radiation therapy. However, occult metastasis and locoregional recurrence influence therapy and outcome. Tumor budding is an emerging prognostic pathological factor in many carcinomas, but has not yet been adequately considered in salivary gland carcinomas.

Methods

We conducted a retrospective single-center study of 64 patients diagnosed with low-grade carcinoma of the major salivary glands treated between 2003 and 2017. Pathological risk factors and TNM classification were thoroughly assessed for each case. All hematoxylin and eosin (HE)-stained histological specimens underwent careful examination, and tumor budding was identified following the guidelines set forth by the International Tumor Budding Consensus Conference in 2016.

Results

Tumor budding was not statistically significant concerning 5-year survival rate (5-YSR) (p=0.969) and mean overall survival (log-rank p=0.315). Whereas 5-year disease-free survival rate (5-YDFSR) was 87% in the low tumor budding group and 61.1% in the intermediate and high tumor budding group (p=0.021). Mean disease-free survival accounted for 100.2 months (CI: 88.6;111.9) in the low budding score group and 58.7 months (CI: 42.8;74.6) in the other group (log-rank p=0.032). Notably, pT1/2 showed significantly lower tumor buds than pT3/4 stages (2.43 tumor buds/0.785 mm2 vs. 4.19 tumor buds/0.785 mm2, p=0.034). Similar findings were noted comparing nodal-positive and nodal-negative patients, as well as patients with and without lymphovascular invasion and perineural invasion (each p<0.05).

Conclusions

Tumor budding might be used as an additional prognostic factor for recurrence in low-grade salivary gland carcinoma, seemingly associated with a higher nodal metastasis rate and advanced tumor stages and a worse 5-YDFSR. Consequently, the evaluation of tumor budding in resection specimens of low-grade salivary gland tumor may prove valuable in decision-making for neck dissection and follow-up strategy.

Mucoepidermoid carcinoma of the hard palate mimicking a dental abscess: Case report

Mucoepidermoid carcinoma is a malignant tumor that arises from the salivary glands. The recommended treatment strategy typically involves surgical intervention, sometimes complemented by radiotherapy, depending on the histological grade of the tumor. A case of a 22-year-old female patient without medical history was described. The clinical examination revealed a bluish lesion located on the hard palate. The histological examination confirmed the diagnosis of a low-grade mucoepidermoid carcinoma. Resection of the lesion was performed and oro-nasal communication was immediately closed by a prosthetic obturator and later on by a rotational palate flap. The patient was followed up for 12 months, and there was no evidence of any recurrence. This article highlights the importance of prompt clinical diagnosis of such lesions and provides an opportunity to review these cancer therapeutic measures to reduce postoperative morbidity.

Clinical Behavior of the Mucoepidermoid Carcinoma of the Larynx-A Scoping Review

OBJECTIVE

Mucoepidermoid carcinomas (MEC) of the larynx account for less than 1% of all laryngeal tumors. The unique features and clinical behavior of these rare entities remain unknown. To fill this knowledge gap, we performed a scoping review of every reported case of laryngeal MEC to study the clinical behavior and the treatment modalities in this rare entity.

REVIEW METHODS

We followed the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) statement.

DATA SOURCES

MedLine, Google Scholar, and Science Direct databases were searched to identify eligible studies.

RESULTS

We concluded with 25 studies and overall 66 cases. Our study revealed that the average age of cases was 55.7 years, and the range was from 12 to 81 years, with younger onset in females. Supraglottic (60%) is the most common subsite of laryngeal MEC s followed by glottis (27.3%). Supraglottic carcinomas frequently present with metastatic neck disease at the time of the initial diagnosis and require more extensive surgical approaches. Surgery with negative surgical margins seems to be the cornerstone in the treatment of MEC. Radiation therapy has not been tested widely as monotherapy but is considered a useful adjuvant modality.

CONCLUSION

This study suggests that negative surgical margins seem to be associated to higher disease control rate and that high-grade supraglottic cases likely benefit from addressing neck disease simultaneously.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2578-2584, 2024.

TGFβ signaling pathway in salivary gland tumors

OBJECTIVE

Pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) are the most prevalent salivary gland tumors. Their pathogenesis has been recently associated with complex molecular cascades, including the TGFβ signaling pathway. The aim of this study was to evaluate the expression of genes associated with the TGFβ signaling pathway (TGFB1, ITGB6, SMAD2, SMAD4, FBN1, LTBP1, and c-MYC) to map possible downstream alterations in the TGFβ cascade.

DESIGN

Thirteen PA, 17 MEC, 13 ACC, and 10 non-neoplastic salivary gland samples were analyzed by real-time RT-PCR.

RESULTS

Cases of PA presented increased TGFB1, LTPB1, c-MYC, and FBN1 expressions, whereas SMAD2 expression was decreased when compared to non-neoplastic tissue. MEC patients displayed increased expressions of TGFB1, ITGB6, FBN1, and c-MYC and decreased expressions of SMAD2 and SMAD4. ACC cases exhibited elevated expressions of the investigated genes except TGFB1. The present results suggest that decreased expression of SMAD2 and SMAD4 does not impede the transcriptional regulation of c-MYC, especially in PA and MEC. Increased expressions of ITGB6, TGFB1, LTBP1, and FBN1 appear to be related to the regulation of the TGFβ signaling pathway in these tumors. Additionally, we observed a higher expression of SMAD4 in ACC and a raised expression of ITGB6 and lowered expression of SMAD2 in MEC.

CONCLUSIONS

Our study demonstrated the differential expression of TGFβ cascade members in salivary gland tumors such as SMAD2/SMAD4 and c-MYC as well as the participation of ITGB6, TGFB1, LTBP1, and FBN1, contributing to the understanding of the mechanisms involved in tumor progression.

Brain metastases of the mucoepidermoid lung carcinoma: a case report

Mucoepidermoid carcinoma, a salivary gland tumor, rarely occurs in bronchial mucous glands. Brain metastases are rarely seen which makes for a challenging diagnosis and treatment approach. A 40-year-old woman presented with confusion, and ataxia, accompanied by a declining Glasgow Coma Score. Brain computerized tomography revealed two hyperdense, postcontrast-enhanced infra- and supratentorial lesions with perifocal edema. First causing obstructive hydrocephalus. The initial surgery involved external ventricular drainage system placement leading to the patient's clinical improvement. After radiological diagnostics, both lesions were resected without complications. Histopathological analysis revealed solid clusters of atypical, polygonal epithelial cells exhibiting mucin production, classified as a poorly differentiated mucoepidermoid carcinoma metastasis which originated from the upper lobe's apicoposterior segment and left lung. The correct treatment approach remains elusive due to the infrequent occurrence and challenging diagnosis. While new oncological and radiosurgery options promise improved overall survival rates, radical resection remains the preferred initial option.

Molecular Aspects of Mucoepidermoid Carcinoma and Adenoid Cystic Carcinoma of the Salivary Gland

BACKGROUND

Salivary gland tumors (SGTs) are rare and highly heterogeneous lesions, making diagnosis a challenging activity. In addition, the small number of studies and samples evaluated difficults the determination of prognosis and diagnosis. Despite the solid advances achieved by research, there is still an intense need to investigate biomarkers for diagnosis, prognosis and that explain the evolution and progression of SGTs.

METHODS

We performed a comprehensive literature review of the molecular alterations focusing on the most frequent malignant SGTs: mucoepidermoid carcinoma and adenoid cystic carcinoma.

RESULTS

Due to the importance of biomarkers in the tumorigenenic process, this review aimed to address the mechanisms involved and to describe molecular and biomarker pathways to better understand some aspects of the pathophysiology of salivary gland tumorigenesis.

CONCLUSIONS

Molecular analysis is essential not only to improve the diagnosis and prognosis of the tumors but also to identify novel driver pathways in the precision medicine scenario.

Adenoid cystic carcinoma of the retromolar pad region: A case report

INTRODUCTION

Adenoid cystic carcinoma (ACC) is one of the most common salivary gland malignancies, mostly occurs in the major and minor salivary glands in the oral and maxillofacial region. The development of ACC in the retromolar pad is extremely rare, which limits establishing proper diagnosis and management.

PRESENTATION OF CASE

A patient described a 2-month history of finding a mass behind the lower left posterior teeth. Based on the physical examination and radiographic findings, we got an initial impression of a benign mucocele, the nature of which was to be investigated further. Pathological examination of the resected tissue resulted in a diagnosis of ACC. Follow-up visits showed no recurrence during the subsequent 54 months.

DISCUSSION

In cases with an uncertain diagnosis based on medical history, clinical features and imaging examinations, it is important to proceed carefully with the possibility of a tumor in mind.

CONCLUSION

ACC in the retromolar pad is rare and can be easily misdiagnosed. Clinical, radiographic, and pathological evidence confirm a definitive diagnosis. Long-term follow-up is important for the full analysis of ACC treatment.

Machine learning-based survival prediction nomogram for postoperative parotid mucoepidermoid carcinoma

Parotid mucoepidermoid carcinoma (P-MEC) is a significant histopathological subtype of salivary gland cancer with inherent heterogeneity and complexity. Existing clinical models inadequately offer personalized treatment options for patients. In response, we assessed the efficacy of four machine learning algorithms vis-à-vis traditional analysis in forecasting the overall survival (OS) of P-MEC patients. Using the SEER database, we analyzed data from 882 postoperative P-MEC patients (stages I-IVA). Single-factor Cox regression and four machine learning techniques (random forest, LASSO, XGBoost, best subset regression) were employed for variable selection. The optimal model was derived via stepwise backward regression, Akaike Information Criterion (AIC), and Area Under the Curve (AUC). Bootstrap resampling facilitated internal validation, while prediction accuracy was gauged through C-index, time-dependent ROC curve, and calibration curve. The model's clinical relevance was ascertained using decision curve analysis (DCA). The study found 3-, 5-, and 10-year OS rates of 0.887, 0.841, and 0.753, respectively. XGBoost, BSR, and LASSO stood out in predictive efficacy, identifying seven key prognostic factors including age, pathological grade, T stage, N stage, radiation therapy, chemotherapy, and marital status. A subsequent nomogram revealed a C-index of 0.8499 (3-year), 0.8557 (5-year), and 0.8375 (10-year) and AUC values of 0.8670, 0.8879, and 0.8767, respectively. The model also highlighted the clinical significance of postoperative radiotherapy across varying risk levels. Our prognostic model, grounded in machine learning, surpasses traditional models in prediction and offer superior visualization of variable importance.

Low-grade mucoepidermoid carcinoma mimicking benign cystic lesions in the salivary gland: A diagnostic dilemma

Mucoepidermoid carcinoma (MEC) is a common malignancy arising in the parotid gland. The diagnosis of MEC is typically based on its morphological features alone, characteristically containing mucocytes, intermediate cells and epidermoid cells. However, when cystic degeneration is diffuse, it is challenging to distinguish MEC from other benign cystic tumors. This is a case report of a 58-year-old Caucasian man who presented with a parotid mass. H&E sections of the mass reveal multiloculated cysts lined by bland-looking epithelium with only rare papillary architectures. The papillary proliferation contains mucocytes, and epidermoid cells highlighted by the p63 immunohistochemistry study. The diagnosis was confirmed by FISH result of positive MAML2 (11q21) rearrangement. Patient underwent parotidectomy and is disease-free 6 months post-surgery. MEC with cystic degeneration is a common diagnostic pitfall which can mimic many benign lesions in the salivary gland. We present a rare case with MEC with extensive cystic change, its molecular and pathologic findings and review the diagnostic features of MEC, its benign mimickers and useful tools for distinguishing these entities.

Re-evaluating a historic cohort of sinonasal and skull base mucoepidermoid carcinoma: an institutional experience

AIMS

Primary mucoepidermoid carcinomas (MECs) of the sinonasal tract and nasopharynx are rare entities that represent a diagnostic challenge, especially in biopsy samples. Herein, we present a case series of MECs of the sinonasal and skull base and its mimics to evaluate the clinicopathological and molecular characteristics in order to avoid misdiagnosis.

METHODS

We reviewed the pathology records of patients diagnosed from 2014 to 2022. Thirty MECs were consecutively diagnosed during that period.

RESULTS

Based on morphological and fluorescence in situ hybridization (FISH) analyses, 30 tumors originally diagnosed as MECs were separated into MAML2 fusion-positive (7 cases) and MAML2 fusion-negative groups (23 cases), in which 14 tumors were positive for the EWSR1::ATF1 fusion; these tumors were reclassified to have hyalinizing clear cell carcinoma (HCCC). The remaining nine MAML2 FISH negative cases were reconfirmed as squamous cell carcinoma (SCC, 3 cases) which showed keratinization and high Ki-67 expression; DEK::AFF2 carcinomas (2 cases), in which DEK gene rearrangement was detected by FISH; and MECs as previously described (4 cases) with typical morphological features. Including 7 MAML2 rearrangements tumors, 11 MEC cases had a male-to-female ratio of 4.5:1, and 6 tumors arose from the nasopharyngeal region, while 5 tumors arose from the sinonasal region. The prognosis of this series of salivary gland-type MECs was favorable.

CONCLUSIONS

Our study confirmed that HCCC runs the risk of being misdiagnosed as MEC in the sinonasal tract and nasopharynx, particularly with biopsy specimens. Careful histological evaluation with supporting molecular testing can facilitate pathological diagnoses.

Salivary gland carcinoma: Towards a more personalised approach

Salivary Gland carcinomas (SGCs) are rare tumors accounting for less than 1% of all cancers with 21 histologically diverse subtypes. The rarity of the disease presents a challenge for clinicians to conduct large size randomized controlled trials. Surgery and radiotherapy remain the only curative treatment for localized disease, whereas treatments for recurrent and metastatic disease remain more challenging with very disappointing results for chemotherapy. The different histological subtypes harbor various genetic alterations, some pathognomonic with a diagnostic impact for pathologists in confirming a difficult diagnosis and others with therapeutic implications regardless of the histologic subtype. Current international guidelines urge pathologists to identify androgen receptor status, HER-2 expression that could be determined by immunohistochemistry, and TRK status in patients with non-adenoid cystic salivary gland carcinoma that are eligible to initiate a systemic treatment, in order to offer them available targeted therapies or refer them to clinical trials based on their mutational profile. A more advanced molecular profiling by next generation sequencing would offer a larger panel of molecular alterations with possible therapeutic implications such as NOTCH, PI3K, BRAF, MYB, and EGFR. In the following review, we present the most common genetic alterations in SGCs as well as actionable mutations with the latest available data on therapeutic options and upcoming clinical trials.

Histologic grading of salivary gland mucoepidermoid carcinoma: A comparison of four grading systems and correlation with survival

BACKGROUND

Mucoepidermoid carcinoma (MEC) is the most common malignant lesion of salivary glands. A number of histologic grading systems are in use for MEC with variable agreement between them.

METHODS

This study was aimed at comparison of four grading systems for MEC: two qualitative (modified Healy and MSKCC grading) and two quantitative (AFIP and Brandwein grading). A retrospective search for diagnosed cases of MEC over eight years yielded 11 cases with adequate clinical details and histologic slides available for review. All cases were reviewed and graded as per the four grading systems. An inter-system agreement was assessed, and Kaplan-Meier analysis was performed to correlate the grading with clinical outcomes.

RESULTS

A general agreement between all four grading systems was seen in 72.7% of cases. Brandwein grading assigned the highest percentage of high grades (18.2%), whereas Memorial Sloan-Kettering Cancer Center (MSKCC) assigned the highest percentage of low-grade MEC (72.7%). The agreement between MSKCC and modified Healy was highest at 90% of cases. There was generally a poor agreement between MSKCC and Brandwein grading systems. The MSKCC grading system showed a significant correlation with disease-free survival in MEC patients.

CONCLUSION

Hence, the MSKCC grading system might serve as a better histologic grading system with a predictive value for the biologic behavior of the tumor. Further larger studies are required to validate these findings and implement the uniform use of MSKCC grading for MEC of salivary glands.

Utilizing orthodontic appliances to retain and disguise a pediatric maxillary obturator throughout growth

Unique challenges are encountered when providing an obturator for an adolescent patient. Challenges include the need to modify the obturator throughout growth, engaging the mixed dentition or partially erupted teeth with minimal undercuts, the psychosocial challenges of an actively maturing patient, and the possible need for coincidental orthodontic therapy. This clinical report describes the ongoing rehabilitation of a patient who presented at the age of 10 with a biopsy-confirmed palatal mucoepidermoid carcinoma. Incorporating orthodontic brackets for retention of innovative adjustable obturator clasps allowed for the favorable function of the obturator prosthesis and the ability to alter the prosthesis over time.

Cystic lesions in the salivary gland. Pitfalls to be avoided on cytology

Cystic lesions of the salivary glands are very uncommon entities. However, on occasion, some neoplasms of the salivary glands show a cystic component, which may be predominant or only partially cystic. Basal cell adenoma, canalicular adenoma, oncocytoma, sebaceous adenoma, intraductal papilloma, epithelial-myoepithelial carcinoma, intraductal carcinoma, and secretory carcinoma are such cystic entities. Cystic degeneration and necrosis, which can develop within solid tumours, represent another possibility. The ability to recognise this type of lesion is a challenge in diagnostic cytology because hypocellular fluid is frequently recovered. Furthermore, evaluating all of the differential diagnoses for cystic lesions of the salivary glands is helpful in obtaining the correct diagnosis. Herein, we evaluate the various types of cystic lesions within the salivary glands.

Number of positive lymph nodes is superior to neck stage of the 8th AJCC in predicting prognosis in parotid mucoepidermoid carcinoma

BACKGROUND

To clarify the impact of the number of positive lymph nodes (LNs) on the prognosis of parotid mucoepidermoid carcinoma (MEC).

METHODS

Patients who underwent neck dissection for parotid MEC were retrospectively enrolled. The primary outcome variable was overall survival (OS). Associations between OS and LN factors, including the AJCC N stage, intraparotid LN metastasis, number of positive LNs, LN size, and extranodal extension (ENE), were evaluated using Cox proportional hazard regression analyses.

RESULTS

A total of 720 patients were included with a mean age of 56 ± 16 years. There was no additional survival compromise until two positive LNs were presented. After adjusting for the number of positive LNs, intraparotid LN metastasis, ENE, and LN size were not related to prognosis. Our proposed N stage based on the number of metastatic LNs (0/1 vs. 2-4 vs. 5+) showed a superior C-index to the AJCC N stage in OS prediction.

CONCLUSION

Quantitative LN burden was an important determinant of prognosis, and the proposed N stage provided better OS stratification than the AJCC N stage.

Malignant Minor Salivary gland neoplasms ofLarynx: Our Experience

<br><b>Introduction:</b> Malignant minor salivary gland tumors are rare, accounting for fewer than 1% of all laryngeal cancers.</br> <br><b>Aim:</b> This study aims to share our experiences regarding clinical, radiological, pathological profiles and their management.</br> <br><b>Materials and methods:</b> The current study reviews 11 cases of malignant minor salivary gland tumors of the larynx treated surgically at our Institute between 2005 and 2019.</br> <br><b>Results:</b> The mean age of the patients was 54 years (range 38-75 years) with six females and five males in the series (1.2:1). Subglottis and trachea were the sites of origin in 54% of the cases, and hoarseness with dyspnea were the most common presenting symptoms. There were nine Adenoid cystic and two Mucoepidermoid carcinoma patients. Surgery was the primary mode of treatment.</br> <br><b>Conclusions:</b> Most of the larynx's malignant minor salivary gland tumors are submucosal in origin. The outcome and prognosis vary considerably based on the tumor's histology, grade, and stage.</br>.

A case of lung carcinoma with a unique biphasic feature: Implications for histogenesis of "fake mucoepidermoid carcinoma" developing in the peripheral lung

We present a case of lung carcinoma with a unique biphasic feature. The patient was a 67-year-old male smoker with idiopathic pulmonary fibrosis (IPF). A subpleural tumor in the left lower lobe, embedded in fibrotic tissue, was resected. Histologically, the tumor consisted of major and minor components of mucoepidermoid carcinoma (MEC) and surrounding conventional lepidic adenocarcinoma, respectively. Both components had the same TP53 somatic mutation (p.V157F) but not Mastermind-like 2 (MAML2) gene rearrangement. The two components may have developed from an identical origin. The tumor could be trans-differentiating from lepidic adenocarcinoma to MEC, possibly promoted by IPF-induced tissue damage. The final diagnosis was "adenosquamous carcinoma with mucoepidermoid-like features (that may originate from lepidic adenocarcinoma)." This case has implications for the potential histogenesis of peripheral lung MEC. Over time, the MEC would expand and outgrow the lepidic adenocarcinoma, making it impossible to distinguish between fake and true MEC. The present case suggests that peripheral MEC could differ from proximal MEC in its histogenesis and molecular genetics. Thus, careful examination is necessary to diagnose peripheral lung MEC, particularly in patients with interstitial lung diseases.

Overexpression of LAG3, TIM3, and A2aR in adenoid cystic carcinoma and mucoepidermoid carcinoma

OBJECTIVE

Adenoid cystic carcinoma (AdCC) and mucoepidermoid carcinoma (MEC) are the two most frequent malignancies of salivary glands. This study aims to explore the expression and migration of LAG3, TIM3, and A2aR in AdCC and MEC, and the potential relationship with oncogenic signaling molecules and immunosuppressive cytokines.

MATERIALS AND METHODS

Custom made human salivary gland tissue microarrays included 81 AdCCs, 52 MECs, 76 normal salivary glands (NSG), and 14 pleomorphic adenoma (PMA) samples. Immunohistochemical analysis of lymphocyte activation gene 3 (LAG3), T-cell immunoglobulin and mucin domain-containing protein 3 (TIM3), adenosine 2a receptor (A2aR), oncogenic phosphorylated S6 kinase (p-S6) and ERK_1/2 (p-ERK_1/2 ), and TGF-β1 was performed with salivary gland tissue microarrays of human samples. The correlation of the immunostaining was analyzed based on a digital pathological system, and data were evaluated by hierarchical cluster. Further in vitro studies of knockdown immune checkpoints LAG3, TIM3, and A2aR were carried out by siRNA transfection.

RESULTS

The expression levels of LAG3, TIM3, and A2aR were remarkably increased in AdCC and MEC, compared with NSG and PMA samples, but were independent of pathology grade. They were closely correlated with TGF-β1, slightly related to p-ERK_1/2 and p-S6. After the knockdown of immune checkpoints LAG3, TIM3, and A2aR, the migration of SACC-LM cell line was significantly reduced.

CONCLUSIONS

These results suggested that LAG3, TIM3, and A2aR are overexpressed in AdCC and MEC, may promote migration of SACC-LM cell and correlated with TGF-β1 and oncogenic signaling pathways.

High-grade mucoepidermoid carcinoma of the salivary gland in a bull

Salivary gland neoplasia is uncommon in veterinary species and has rarely been reported in cattle. Adenocarcinoma, squamous cell carcinoma, and pleomorphic carcinoma have been described in the parotid gland of dairy cows. Here we describe a case of high-grade mucoepidermoid carcinoma in a bull. The bull had a chronic history of caudal mandibular soft tissue swelling. Postmortem examination revealed a 30 × 30-cm mass with a caseonecrotic center, hemorrhage and necrosis of the ipsilateral cervical musculature, osteolysis of the right paracondylar process of the skull and right horn base, pulmonary nodules, and enlarged tracheobronchial lymph nodes. Histology of the mass, lungs, and lymph nodes revealed an invasive neoplasm composed of epithelial cells arranged in nests and ductular structures supported by a spindle cell stroma, with frequent central necrosis. Immunohistochemistry revealed that epithelial cells were diffusely positive for pancytokeratin and p63 with multifocal vimentin positivity; stromal cells were diffusely positive for vimentin and α-SMA. A salivary gland mucoepidermoid carcinoma was diagnosed based on these findings. Although rare, salivary gland neoplasia should be considered a differential diagnosis for mandibular masses in cattle.

Recurrent Giant Mucoepidermoid Carcinoma of the Parotid: A Case Report and Review of Literature

Mucoepidermoid carcinoma is the most common salivary gland malignancy and about one third occurs in the parotid gland. The peak incidence is commonly seen between the third and fifth decades of life. It routinely presents as a fixed, painless mass below the ear. However, its presentation as a giant mass is exceedingly rare. Here, we report a case of a recurrent giant exophytic mucoepidermoid carcinoma in a young male. He underwent Revision Total Parotidectomy with Modified Radical neck dissection with Sural nerve grafting and an Anterolateral thigh flap reconstruction followed by Adjuvant radiotherapy. The rarity of the clinical presentation and the management challenges faced in a young male are being discussed in this case report.

The Therapeutic Landscape of Salivary Gland Malignancies-Where Are We Now?

Salivary gland malignancies (SGMs) account for less than 5% of new diagnoses in head and neck tumors. If feasible, surgery is the preferred treatment modality. Nevertheless, some malignancies have a tendency of recurrence, with possible distant metastasis. Alternative treatment strategies, such as primary radiation or chemotherapeutics, often present low response rates. As a result, there is an unmet need for novel therapeutic approaches. Nowadays, target-based therapies (e.g., small inhibitors and immunotherapy) are used by the medical oncologist for possible treatment of advanced SGMs. Based on recent published trials, some novel treatments may provide additional disease control for some patients. However, sample sizes are small, the general findings are unsatisfactory, and a lot of uncertainties remain to be elucidated. Nevertheless, research shows that patients do not benefit from blind administration of systemic treatments and therefore a more personalized approach is highly needed. The aim of this review paper is to summarize the most recent advances in the biological understanding and molecular pathways of salivary gland cancers, the association of these pathways with the current treatments used and their implications for more personalized targeted-based therapies.

Bioinformatic Analysis for Mucoepidermoid and Adenoid Cystic Carcinoma of Therapeutic Targets

Salivary gland neoplasms are a heterogeneous neoplasm group, including mucoepidermoid carcinoma (MECa), adenoid cystic carcinoma (AdCC), and many others. Objective: We aimed to identify new critical genes of MECa and AdCC using bioinformatics analysis. Methods: Gene expression profile of GSE153283 was analyzed by the GEO2R online tool to use the DAVID software for their subsequent enrichment. Protein–protein interactions (PPI) were visualized using String. Cytoscape with MCODE plugin followed by Kaplan–Meier online for overall survival analysis were performed. Results: 97 upregulated genes were identified for MECa and 86 for AdCC. PPI analysis revealed 22 genes for MECa and 63 for AdCC that were validated by Kaplan–Meier that showed FN1 and SPP1 for MECa, and EGF and ERBB2 for AdCC as more significant candidate genes for each neoplasm. Conclusion: With bioinformatics methods, we identify upregulated genes in MECa and AdCC. The resulting candidate genes as possible therapeutic targets were FN1, SPP1, EGF, and ERBB2, and all those genes had been tested as a target in other neoplasm kinds but not salivary gland neoplasm. The bioinformatic evidence is a solid strategy to select them for more extensive research with clinical impact.

Unicystic Mucoepidermoid Carcinoma: A Pitfall for Clinical and Pathologic Diagnosis

Unicystic mucoepidermoid carcinoma (UC-MEC) is a rare MEC variant, and its diagnosis is frequently problematic. This study is aimed at summarizing its clinicopathologic characteristics, treatment, and prognosis and proposing key points to avoid missed diagnosis and misdiagnosis in clinical and pathological conditions. This retrospective study included 30 UC-MEC cases, and the clinical findings were collected from the clinical medical records. Radiographic features, histologic behaviors, MAML2 rearrangement by fluorescence in situ hybridization (FISH), and follow-up data were analyzed. Moreover, glandular odontogenic cyst (GOC) and cytadenoma (CA) were used as controls. In the UC-MEC group, 19 patients were female (63%), and 11 were male (37%). The mean patient age was 39.5 (range, 7–72 years). The affected locations included the jaw (8 maxillary, 3 mandibular) and salivary glands (7 parotid, 11 palates, and 1 floor of the mouth). The chief complaint was swelling; the lesions were all cystic, among which 66.7% were well circumscribed and 33.3% poorly defined. Microscopic examination showed two UC-MEC histologic subtypes. Type A presented as a single cyst with mural thickening (8/30, 27%) lined predominantly by epidermoid cells with interspersed intermediate and mucinous cells, and type B (22/30, 73%) showed infiltrative tumor islands in the cystic wall or the surrounding tissue. FISH analysis suggested that approximately 66.7% of UC-MEC harbored a MAML2 rearrangement. During the median follow-up period of 42 months (range, 6–120 months), all type A patients and 68% of type B patients who underwent complete surgical resection lived without relapse. Seven cases with type B cancer that underwent curettage initially had local recurrence. Clinicians and pathologists hardly recognize UC-MEC owing to its cystic architecture. Specific epidermoid, mucous, and intermediate tumor cells, and MAML2 fusion testing, are essential to avoid potential diagnostic pitfalls. Prompting and completing resection surgery with negative margins would have a favorable prognosis.

Tumour Seeding Following Core Biopsy of a Mucoepidermoid Carcinoma of the Parotid: Radiological Evidence and a Surgical Approach to En-Bloc Dissection of the Mass and Tract

Tumour seeding along the needle tract following core needle biopsy of the parotid is a recognised complication. We present a unique case of mucoepidermoid carcinoma of the parotid in an 18-year-old patient with associated tumour seeding within the core needle biopsy tract. Tumour seeding was confirmed both histologically and radiologically on magnetic resonance imaging as early as 35 days post-biopsy. The patient was treated successfully with a combination of surgery and adjuvant proton beam therapy. This case also visually demonstrates a surgical approach to en-block excision of the mass and tract.

Polarized Microscopic Analysis of Picrosirius Red Stained Salivary Gland Pathologies: An Observational Study

OBJECTIVE

 Salivary gland diseases and their pathologies may affect the glandular structure including collagen, a major stromal component, in response to tissue damage or diseases. This study aimed to examine the changes in collagens in different salivary gland diseases using polarized picrosirius red staining.

MATERIALS AND METHODS

 The submandibular gland samples diagnosed as sialadenitis, chronic sclerosing sialadenitis, pleomorphic adenoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma were stained with picrosirius red, Masson's trichrome, and anticollagen I staining. The quantity of collagens was examined and reported as a percentage of positive picrosirius red area. The maturity of collagens was studied with polarized light microscope and reported as a percentage of orange-red and yellow-green polarized collagens, representing the mature and immature collagens, respectively.

STATISTICAL ANALYSIS

 The % positive areas for picrosirius red representing the collagen amount among salivary gland diseases were analyzed by one-way analysis of variance with Tukey's test. The % orange-red and % yellow-green polarized areas representing the collagen maturity were analyzed by Kruskal-Wallis test and Mann-Whitney U test.

RESULTS

 The malignant tumors, adenoid cystic carcinoma (29.92) and mucoepidermoid carcinoma (26.59), had higher significant percentage of positive picrosirius red area, compared with the benign tumor (14.56), chronic sclerosing sialadenitis (10.61), and sialadenitis (7.22) (p < 0.05). The percentages of orange-red polarized areas are 48.07, 39.6, 62.67, 83.75, and 76.05 in sialadenitis, chronic sclerosing sialadenitis, pleomorphic adenoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma, respectively. This percentage tended to increase in the benign and malignant lesions with statistical difference, compared with the inflammatory lesions (p < 0.05). There was no statistical difference in the percentages of yellow-green polarized areas among various salivary gland diseases. In addition, the results of Masson's trichrome and anticollagen I staining are corresponding to that of picrosirius red among various salivary gland diseases.

CONCLUSIONS

 Polarized picrosirius red demonstrated the most amounts of collagen in the malignant lesion, and represented the different maturity of collagens in each lesion group. Studying the amounts and maturity of collagen with picrosirius red for extracellular matrix alteration in salivary gland diseases along with routine hematoxylin and eosin, Masson's trichrome, and immunohistochemistry may provide a better understanding in different salivary gland pathologies.

The Diagnostic Value of Ultrasound-Based Deep Learning in Differentiating Parotid Gland Tumors

Objectives. Evidence suggests that about 80% of all salivary gland tumors involve the parotid glands, with approximately 20% of parotid gland tumors (PGTs) being malignant. Discriminating benign and malignant parotid gland lesions preoperatively is vital for selecting the appropriate treatment strategy. This study explored the diagnostic performance of deep learning system for discriminating benign and malignant PGTs in ultrasonography images and compared it with radiologists. Methods. A total of 251 consecutive patients with surgical resection and proven parotid gland malignant or benign tumors who underwent preoperative ultrasound examinations were enrolled in this study between January 2014 and November 2020. Next, we compared the diagnostic accuracy of deep learning methods (ViT-B\16, EfficientNetB3, DenseNet121, and ResNet50) and radiologists in parotid gland tumor. In addition, the area under the curve (AUC), specificity, sensitivity, positive predictive value, and negative predictive value were calculated. Results. Among the 251 patients, 176/251 were the training set, whereas 75/251 were the validation set. Results showed that 74/251 patients had malignant tumor. Deep learning models achieved good performance in differentiating benign from malignant tumors, with the diagnostic accuracy and AUCs of ViT-B\16, EfficientNetB3, DenseNet121, and ResNet50 model being 81% and 0.81, 80% and 0.82, 77% and 0.81, and 79% and 0.80, respectively. On the other hand, the diagnostic accuracy and AUCs of radiologists were 77%-81% and 0.68-0.75, respectively. It was evident that the diagnostic accuracy of deep learning methods was higher than that of inexperienced radiologists, but there was no significant difference between deep learning methods and experienced radiologists. Conclusions. This study shows that the deep learning system can be used for diagnosing parotid tumors. The findings also suggest that the deep learning system may improve the diagnosis performance of inexperienced radiologists.

Iodine-125 brachytherapy for the treatment of central mucoepidermoid carcinoma of the jaw in a pre-teen

Central mucoepidermoid carcinoma (MEC) of the jaw is a rare malignant neoplasm, even rarer in teenagers. Radical surgical resection, such as en bloc resection or segmental resection, is the main treatment for MEC of the jaw. This surgical treatment results in a loss of integrity of the jaw. The successful application of iodine-125 brachytherapy for the treatment of intraosseous MEC of the mandible in an 11-year-old girl is reported here. No local recurrence or distant metastasis was observed during 6 years of follow-up. The integrity of the mandible was preserved and the development of the mandible was not significantly affected. Iodine-125 brachytherapy is a potential alternative treatment for central mucoepidermoid carcinoma of the jaw, especially in teenagers, and may preserve the continuity and function of the jaw.

Mammary analogue secretory carcinoma: A challenging case arising in a young man with radiation exposure

Mammary Analogue Secretory Carcinoma (MASC) is a recently described salivary gland tumor frequently sampled via fine-needle aspiration. The cytologic features of MASC are not entirely distinctive and can simulate acinic cell carcinoma, but the tumor harbors an ETV6 gene rearrangement resulting in an ETV6-NTRK3 fusion gene. We present a case of MASC arising in a 31 year old man with a history of multiple radio-embolization procedures.

Outcomes of patients with minor salivary gland mucoepidermoid carcinoma of the palate undergoing submental flap reconstruction following radical resection

OBJECTIVE

To investigate the outcomes of patients with mucoepidermoid carcinoma of the palate undergoing pedicled facial-submental artery island flap (FSIF) reconstruction following resection.

PATIENTS AND METHODS

41 patients with early stage disease and 9 patients with advanced-stage disease underwent radical excision and neck dissection. 37 IIb, 4 class IIa and 9 IIIb maxillary defects were reconstructed with FSIF, folded FSIF or folded FSIF with titanium mesh respectively. The skin paddles were 3 × 8 to 5 × 15 cm and 3 × 8 to 5 × 14 cm, respectively. 5 patients with high grade disease were treated with cobalt 60 adjuvant radiotherapy after operation.

RESULTS

One flap failure occurred, yielding a success rate of 98.0% in the reconstruction of palate II and III defects with FSIF or titanium mesh. The patients were seen for follow-up for 16-60 months postoperative. 76.0% patients alive with no disease (AND); 14.0% patients alive with disease (AD) and 10.0% died of disease (DD). Rates of AND, AD and DD differed significantly according to histopathologic grade and TNM stage (P < 0.001); rates of AND, AD and DD differed obviously according to necrosis of the tumors lymph node metastasis, and tumour cell anaplasia and treatment (P < 0.05).

CONCLUSIONS

Radical resection with wide safety margins of normal tissues including neck dissection is the mainstay of treatment modality. The patients with high grade disease should be treated with postoperative radiotherapy. The FSIF is a reliable and safe method for repairing Brown class II maxillary defects.

Clear Cell Odontogenic Carcinoma a Systematic Review

Clear cell Odontogenic Carcinoma (CCOC) is an uncommon malignant odontogenic tumor (MOT). It is the fifth most common MOT. A systematic review is presented of reported cases, case series and retrospective studies of CCOC, to determine trends in presentation, diagnostic features, treatment, and patient outcome. Searches of detailed databases were carried out to identify papers reporting CCOC. The variables were demographics, patient symptoms, tumor location, histopathological findings, immunohistochemical studies, treatment, follow-up, and recurrence. 117 cases were identified; CCOC was most frequently seen in mature females 65% (n = 76). The total average age was 55.4 with a range from 17 to 89 years, for females 56.4 and males 53.6 years. The mean size was 3.41 cm. The most common location was in the mandibular body 36.2% (n = 42), followed by the anterior mandible 23.3% (n = 27). The most common clinical presentation was a swelling 80.4% (n = 74), and the main symptom was pain 41.3% (n = 31), followed by painless lesion 24% (n = 18). The most common Immunohistochemistry positive expression was CK19, EMA, and CEA, and for special staining periodic acid Shiff (PAS); 97% of cases were treated surgically. The average follow-up was 30.3 months, and recurrence was reported in 52.4% of the cases. Conclusion: CCOC shows a strong predilection for the body and anterior mandible, and females are more frequently affected. CCOCs can be painful and the principle clinical sign is swelling, CCOCs can metastasize, and the prognosis is fair.

Characterization of tumor-associated MUC1 and its glycans expressed in mucoepidermoid carcinoma

Mucoepidermoid carcinoma (MEC) is one of the most frequently misdiagnosed tumors. Glycans are modulated by malignant transformation. Mucin 1 (MUC1) is a mucin whose expression is upregulated in various tumors, including MEC, and it has previously been investigated as a diagnostic and prognostic tumor marker. The present study aimed to reveal the differences in the mucin glycans between MEC and normal salivary glands (NSGs) to discover novel diagnostic markers. Soluble fractions of salivary gland homogenate prepared from three MEC salivary glands and 7 NSGs were evaluated. Mucins in MEC and NSGs were separated using supported molecular matrix electrophoresis, and stained with Alcian blue and monoclonal antibodies. The glycans of the separated mucins were analyzed by mass spectrometry. MUC1 was found in MEC but not in NSGs, and almost all glycans of MUC1 in MEC were sialylated, whereas the glycans of mucins in NSGs were less sialylated. The core 2 type glycans, (Hex)₂(HexNAc)₂(NeuAc)₁ and (Hex)₂(HexNAc)₂(NeuAc)₂, were found to be significantly abundant glycans of MUC1 in MEC. MEC markedly produced MUC1 modified with sialylated core 2 glycans. These data were obtained from the soluble fractions of salivary gland homogenates. These findings provide a basis for the utilization of MUC1 as a serum diagnostic marker for the preoperative diagnosis of MEC.

Stem cell transplantation as treatment for major histocompatibility class I deficiency

Major histocompatibility class I deficiency, due to genetic lesions in TAP1, TAP2, TAPBP, or B2M, manifests with recurrent sinopulmonary infections and granulomatous skin ulceration, and is predominately treated with antimicrobial prophylaxis and chest physiotherapy. One previous report of hematopoietic stem cell transplantation has been described in the literature, demonstrating cure of the immune defect without significant graft-versus-host disease. In this report, we expand the literature on HSCT in MHC-I deficiency with follow-up of the original patient, demonstrating maintained resolution of normal immune function and regression of the granulomatous rash 15 years post-transplant, and describe a further patient with mycobacterial disease whose transplant course was complicated by severe graft-versus-host disease.

Malignant Sinonasal Tumors: Update on Histological and Clinical Management

Tumors of nasal cavity and paranasal sinuses (TuNSs) are rare and heterogeneous malignancies, presenting different histological features and clinical behavior. We reviewed the literature about etiology, biology, and clinical features of TuNSs to define pathologic features and possible treatment strategies. From a diagnostic point of view, it is mandatory to have high expertise and perform an immunohistochemical assessment to distinguish between different histotypes. Due to the extreme rarity of these neoplasms, there are no standard and evidence-based therapeutic strategies, lacking prospective and large clinical trials. In fact, most studies are retrospective analyses. Surgery represents the mainstay of treatment of TuNSs for small and localized tumors allowing complete tumor removal. Locally advanced lesions require more demolitive surgery that should be always followed by adjuvant radio- or chemo-radiotherapy. Recurrent/metastatic disease requires palliative chemo- and/or radiotherapy. Many studies emphasize the role of specific genes mutations in the development of TuNSs like mutations in the exons 4-9 of the TP53 gene, in the exon 9 of the PIK3CA gene and in the promoter of the TERT gene. In the near future, this genetic assessment will have new therapeutic implications. Future improvements in the understanding of the etiology, biology, and clinical features of TuNSs are warranted to improve their management.