Characteristics of 5015 Salivary Gland Neoplasms Registered in the Hiroshima Tumor Tissue Registry over a Period of 39 Years

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

OBJECTIVES

The preoperative classification of pleomorphic adenomas (PMA) and Warthin tumors (WT) in the parotid gland plays an essential role in determining therapeutic strategies. This study aims to develop and validate an ultrasound-based ensemble machine learning (USEML) model, employing nonradiative and noninvasive features to differentiate PMA from WT.

METHODS

A total of 203 patients with histologically confirmed PMA or WT who underwent parotidectomy from two centers were enrolled. Clinical factors, ultrasound (US) features, and radiomic features were extracted to develop three types of machine learning model: clinical models, US models, and USEML models. The diagnostic performance of the USEML model, as well as that of physicians based on experience, was evaluated and validated using receiver operating characteristic (ROC) curves in internal and external validation cohorts. DeLong's test was used for comparisons of AUCs. SHAP values were also utilized to explain the classification model.

RESULTS

The USEML model achieved the highest AUC of 0.891 (95% CI, 0.774-0.961), surpassing the AUCs of both the US (0.847; 95% CI, 0.720-0.932) and clinical (0.814; 95% CI, 0.682-0.908) models. The USEML model also outperformed physicians in both internal and external validation datasets (both p < 0.05). The sensitivity, specificity, negative predictive value, and positive predictive value of the USEML model and physician experience were 89.3%/75.0%, 87.5%/54.2%, 87.5%/65.6%, and 89.3%/65.0%, respectively.

CONCLUSIONS

The USEML model, incorporating clinical factors, ultrasound factors, and radiomic features, demonstrated efficient performance in distinguishing PMA from WT in the parotid gland.

CLINICAL RELEVANCE STATEMENT

This study developed a machine learning model for preoperative diagnosis of pleomorphic adenoma and Warthin tumor in the parotid gland based on clinical, ultrasound, and radiomic features. Furthermore, it outperformed physicians in an external validation dataset, indicating its potential for clinical application.

KEY POINTS

• Differentiating pleomorphic adenoma (PMA) and Warthin tumor (WT) affects management decisions and is currently done by invasive biopsy. • Integration of US-radiomic, clinical, and ultrasound findings in a machine learning model results in improved diagnostic accuracy. • The ultrasound-based ensemble machine learning (USEML) model consistently outperforms physicians, suggesting its potential applicability in clinical settings.

Pleomorphic adenoma and carcinoma ex-pleomorphic adenoma tumorigenesis: A proteomic analysis

OBJECTIVES

To conduct a comprehensive proteomic analysis of normal salivary gland tissue, pleomorphic adenoma (PA), and carcinoma ex-pleomorphic adenoma (CXPA), and validate the proteomic findings using immunohistochemistry.

METHODS

Six normal salivary gland tissues, seven PA and seven CXPA samples underwent laser microdissection followed by liquid chromatography coupled to mass spectrometry. Protein identification and quantification were performed using MaxQuant software. Statistical analysis and functional enrichment were conducted using the Perseus platform and STRING tool, respectively. Immunohistochemistry was used for validation.

RESULTS

Comparative proteomic analysis revealed 2680 proteins across the three tissue types, with 799 significantly altered between groups. Translocation protein SEC63 homolog, Annexin A6 and Biglycan were up-regulated in CXPA compared to PA. Decorin was markedly up-regulated in both PA and CXPA compared to normal salivary gland (log2 fold changes of 7.58 and 7.38, respectively). Validation confirmed elevated levels of Biglycan and Decorin in the extracellular matrix of CXPA compared to PA.

CONCLUSIONS

Proteomic analysis identified differential protein expression patterns associated with malignant transformation of PA into CXPA. Findings indicate a crucial role for extracellular matrix proteins, specifically Biglycan and Decorin, in the tumorigenic progression of PA and CXPA.

Low FDG uptake in lung metastasis despite high FDG uptake in a primary adenoid cystic carcinoma of a sublingual gland

Adenoid cystic carcinoma is a rare malignant tumor that primarily occurs in the salivary glands. There are few reports of sublingual gland adenoid cystic carcinoma with lung metastases on which 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) was performed. We report the case of a 57-year-old Japanese woman with an adenoid cystic carcinoma of the sublingual gland with lung metastases in whom the FDG uptake of the lung metastasis was low despite high FDG uptake in the primary lesion. The pathological examination revealed that solid components were more visible and the Ki-67 index was more positive in the primary lesion compared to the metastatic lesion. We speculate that differences in tumor growth ability might have resulted in the differences in FDG uptake. This case demonstrates that significant differences might occur in the FDG uptake between primary and metastatic tumors.

The Usefulness of Fine Needle Aspiration Cytology in the Management of Parotid Gland Masses at a Tertiary Academic Hospital

Background

Fine needle aspiration cytology (FNAC) is an integral part of the preoperative work-up of parotid tumours.

Aim

To determine the rate of concordance between FNAC and histology following parotidectomy.

Methods

A review of records of patients who had parotidectomy which was preceded FNAC was done. Data collected included patients' demography, presenting symptoms and clinical signs; cytology and post-operative histology results.

Results

Seventy-seven records were found and 14 were excluded. Forty-five (71%: 45/63) of the tumours were benign, 21% (13/63) malignant and 8% (5/63) inflammatory lesions. Forty-one (91.1%: 41/45) of the benign tumours had concordance between FNAC and final histology. Seven (63.6%: 7/11) of FNAC diagnosed malignancies were confirmed on histology.

Conclusion

Around 71% of parotid masses were benign. Painful masses are more likely to be malignant and FNAC is more reliable for the diagnosis of pleomorphic adenoma than rare benign and malignant tumours of the parotid gland.

A nomogram incorporating clinical, conventional ultrasound and shear wave elastography findings for distinguishing pleomorphic adenoma from Warthin's tumor of the major salivary glands

OBJECTIVE

Pre-operative differentiation between pleomorphic adenoma (PA) and Warthin's tumor (WT) of the major salivary glands is crucial for treatment decisions. The purpose of this study was to develop and validate a nomogram incorporating clinical, conventional ultrasound (CUS) and shear wave elastography (SWE) features to differentiate PA from WT.

METHODS

A total of 113 patients with histological diagnosis of PA or WT of the major salivary glands treated at Fujian Medical University Union Hospital were enrolled in training cohort (n = 75; PA = 41, WT = 34) and validation cohort (n = 38; PA = 22, WT = 16). The least absolute shrinkage and selection operator (LASSO) regression algorithm was used for screening the most optimal clinical, CUS, and SWE features. Different models, including the nomogram model, clinic-CUS (Clin+CUS) and SWE model, were built using logistic regression. The performance levels of the models were evaluated and validated on the training and validation cohorts, and then compared among the three models.

RESULTS

The nomogram incorporating the clinical, CUS and SWE features showed favorable predictive value for differentiating PA from WT, with the area under the curves (AUCs) of 0.947 and 0.903 for the training cohort and validation cohort, respectively. Decision curve analysis showed that the nomogram model outperformed the Clin+CUS model and SWE model in terms of clinical usefulness.

CONCLUSIONS

The nomogram had good performance in distinguishing major salivary PA from WT and held potential for optimizing the clinical decision-making process.

Salivary gland neoplasms in small biopsies and fine needle aspirations

Salivary gland neoplasms are rare and represent a diverse group of head and neck tumors. Their diagnosis in limited cellularity specimens can be challenging as many of these have overlapping clinical, radiological presentation, and pathologic features. Fine needle aspiration and/or core biopsies are more of a norm than rarity to be performed preoperatively to provide invaluable information that can guide clinical management including surgery. Even though these limited specimens may not always provide a definitive diagnosis; they have high sensitivity in confirming primary neoplasia, assessing the tumor grade, and ruling out non-surgical disease. An algorithmic pattern based approach can help narrow the differential diagnosis; leading to a definitive diagnosis with the help of specific ancillary studies.

Role of Histone Deacetylases in the Pathogenesis of Salivary Gland Tumors and Therapeutic Targeting Options

Salivary gland tumors (SGTs) comprise a rare and heterogenous category of benign/malignant neoplasms with progressively increasing knowledge of the molecular mechanisms underpinning their pathogenesis, poor prognosis, and therapeutic treatment efficacy. Emerging data are pointing toward an interplay of genetic and epigenetic factors contributing to their heterogeneity and diverse clinical phenotypes. Post-translational histone modifications such as histone acetylation/deacetylation have been shown to actively participate in the pathobiology of SGTs, further suggesting that histone deacetylating factors (HDACs), selective or pan-HDAC inhibitors (HDACis), might present effective treatment options for these neoplasms. Herein, we describe the molecular and epigenetic mechanisms underlying the pathology of the different types of SGTs, focusing on histone acetylation/deacetylation effects on gene expression as well as the progress of HDACis in SGT therapy and the current status of relevant clinical trials.

CT based intratumor and peritumoral radiomics for differentiating complete from incomplete capsular characteristics of parotid pleomorphic adenoma: a two-center study

OBJECTIVE

Capsular characteristics of pleomorphic adenoma (PA) has various forms. Patients without complete capsule has a higher risk of recurrence than patients with complete capsule. We aimed to develop and validate CT-based intratumoral and peritumoral radiomics models to make a differential diagnosis between parotid PA with and without complete capsule.

METHODS

Data of 260 patients (166 patients with PA from institution 1 (training set) and 94 patients (test set) from institution 2) were retrospectively analyzed. Three Volume of interest (VOIs) were defined in the CT images of each patient: tumor volume of interest (VOI_tumor), VOI_peritumor, and VOI_{intra-plus peritumor}. Radiomics features were extracted from each VOI and used to train nine different machine learning algorithms. Model performance was evaluated using receiver operating characteristic (ROC) curves and the area under the curve (AUC).

RESULTS

The results showed that the radiomics models based on features from VOI_{intra-plus peritumor} achieved higher AUCs compared to models based on features from VOI_tumor. The best performing model was Linear discriminant analysis, which achieved an AUC of 0.86 in the tenfold cross-validation and 0.869 in the test set. The model was based on 15 features, including shape-based features and texture features.

CONCLUSIONS

We demonstrated the feasibility of combining artificial intelligence with CT-based peritumoral radiomics features can be used to accurately predict capsular characteristics of parotid PA. This may assist in clinical decision-making by preoperative identification of capsular characteristics of parotid PA.

Salivary gland tumors: A 13-year clinicopathologic retrospective study in a Brazilian northeast population

Background

The present study aimed to evaluate the clinicopathologic features of salivary gland tumors (SGTs) in a Brazillian northeast population.

Material and Methods

A retrospective descriptive cross-sectional study was performed (1995-2009). All cases of SGTs diagnosed in a private surgical pathology service in Brazil were reviewed, and clinicopathological data were collected.

Results

A total of 23.258 histopathological records of biopsies were analyzed, and 174 cases were diagnosed as SGTs (0.7%). Of these, 117 (67.2%) were classified as benign, and 57 (32.8%) were malignant. The series comprised 89 females (51.1%) and 85 males (48.9%), with a mean age of 50.2 years (range: 3-96 years) and a roughly equal female-to-male ratio (1:1). Most tumors occurred in the parotid gland (n = 82, 47.1%), followed by the palate (n = 45, 25.9%), submandibular gland (n = 15, 8.6%). Pleomorphic adenoma (n = 83; 70.9%) and mucoepidermoid carcinoma (n = 19, 33.3%) were the most frequent benign and malignant tumors, respectively. After reevaluation of morphology and immunohistochemical analysis, seven tumors (4.0%) were reclassified following the current WHO Classification of the Head and Neck Tumors.

Conclusions

The general features of SGT from the studied Brazilian population were similar to previously published reports in other countries. However, SGTs do not show any sex predilection. Although careful morphological analysis is the key to the correct diagnosis of these tumors, immunohistochemical analysis is essential to establish an accurate diagnosis in the face of challenging cases. Key words:Salivary gland tumors, epidemiology, head and neck pathology.

Concurrent Warthin tumor and Kimura disease: a case report

BACKGROUND

Warthin tumor (WT) is a common benign salivary tumor of the parotid gland. Clinically, it occurs in men in their fifth to seventh decades who typically smoke cigarettes. WTs have been reported with different head and neck neoplasms and other salivary gland tumors within the same or another salivary gland. Kimura disease (KD) is a rare chronic inflammatory disease with unknown etiology affecting young to middle-aged Asian men. KD presents as an asymptomatic nodule in the head and neck area, with regional lymphadenopathy and salivary gland involvement.

CASE PRESENTATION

A 64-year-old Arabic man presented with a 10-year history of an asymptomatic swelling of the left face. Computed tomography showed a well-defined, multicystic mass with heterogeneous enhancement. The resected mass was composed of two distinct components. There was a well-demarcated proliferation of papillary and cystic oncocytic epithelium with lymphoid stroma, consistent with WT. Some areas exhibited sclerotic fibrosis, with multiple lymphoid follicles showing folliculolysis, follicular hyperplasia, and eosinophilic infiltrate. The patient's immunoglobulin E level serum was elevated, confirming a coexisting KD. The patient underwent a left superficial parotidectomy, with no recurrence at a 30-month follow-up.

CONCLUSION

This report describes the first concurrent case of WT and KD in the parotid gland.

Solitary Scalp Metastases of Parotid Pleomorphic Adenoma: A Case Report

Pleomorphic adenoma (PA) of the parotid gland is considered one of the commonest benign salivary gland neoplasms in both adults and pediatrics. However, metastatic pleomorphic adenoma (MPA) is extremely rare. In the past three decades, multiple cases were reported in the literature of MPA, where the metastatic phase has been preceded by a local recurrence for the majority of the cases. Metastases to the lungs, liver, bone, head and neck were reported. This paper will discuss a rare case presentation of MPA that metastasised solely to the face and scalp subcutaneous tissue with no other sites of metastases in a male adult.

An attention base U-net for parotid tumor autosegmentation

A parotid neoplasm is an uncommon condition that only accounts for less than 3% of all head and neck cancers, and they make up less than 0.3% of all new cancers diagnosed annually. Due to their nonspecific imaging features and heterogeneous nature, accurate preoperative diagnosis remains a challenge. Automatic parotid tumor segmentation may help physicians evaluate these tumors. Two hundred eighty-five patients diagnosed with benign or malignant parotid tumors were enrolled in this study. Parotid and tumor tissues were segmented by 3 radiologists on T1-weighted (T1w), T2-weighted (T2w) and T1-weighted contrast-enhanced (T1wC) MR images. These images were randomly divided into two datasets, including a training dataset (90%) and an validation dataset (10%). A 10-fold cross-validation was performed to assess the performance. An attention base U-net for parotid tumor autosegmentation was created on the MRI T1w, T2 and T1wC images. The results were evaluated in a separate dataset, and the mean Dice similarity coefficient (DICE) for both parotids was 0.88. The mean DICE for left and right tumors was 0.85 and 0.86, respectively. These results indicate that the performance of this model corresponds with the radiologist's manual segmentation. In conclusion, an attention base U-net for parotid tumor autosegmentation may assist physicians to evaluate parotid gland tumors.

Malignant transformation of Warthin's tumor into squamous cell carcinoma: A case report

Malignant transformation of Warthin's tumor into squamous cell carcinoma is rare. The present study reported on a case of a 67-year-old male patient diagnosed with this condition. Microscopically, the tumor was mainly composed of squamous cell carcinoma and lymphoid stroma. Furthermore, the squamous cell carcinoma cells were arranged in a solid flake-like, papillary and cystic shape. Local bleeding was observed in the mass and a large number of lymphoid stroma-associated centers were observed between the cancer cells. The expression of cytokeratin (CK)5/6, P40, CK7, CK18, CK8 and MutS protein homolog 2 was detected by immunohistochemistry, in addition to Epstein-Barr encoding region in situ hybridization (−), Ki-67 (epithelial 25% +) and p53 (wild-type). The diagnosis of malignant transformation of Warthin's tumor into squamous cell carcinoma depends on the histopathology. The microscopic diagnosis is based on the dynamic process of scaling, atypical hyperplasia and cancerization of the eosinophilic columnar epithelium. Of note, it is also necessary to differentiate it from cervical malignant tumors such as lymphoepithelial carcinoma. The main clinical treatment is surgical resection with negative margins.

Distribution and Frequency of Salivary Gland Tumours: An International Multicenter Study

BACKGROUND

Salivary gland tumours (SGT) are a relatively rare group of neoplasms with a wide range of histopathological appearance and clinical features. To date, most of the epidemiological studies on salivary gland tumours are limited for a variety of reason including being out of date, extrapolated from either a single centre or country studies, or investigating either major or minor glands only.

METHODS

This study aimed to mitigate these shortcomings by analysing epidemiological data including demographic, anatomical location and histological diagnoses of SGT from multiple centres across the world. The analysed data included age, gender, location and histological diagnosis from fifteen centres covering the majority of the world health organisation (WHO) geographical regions between 2006 and 2019.

RESULTS

A total of 5739 cases were analysed including 65% benign and 35% malignant tumours. A slight female predilection (54%) and peak incidence between the fourth and seventh decade for both benign and malignant tumours was observed. The majority (68%) of the SGT presented in major and 32% in the minor glands. The parotid gland was the most common location (70%) for benign and minor glands (47%) for malignant tumours. Pleomorphic adenoma (70%), and Warthin's tumour (17%), were the most common benign tumours whereas mucoepidermoid carcinoma (26%) and adenoid cystic carcinoma (17%) were the most frequent malignant tumours.

CONCLUSIONS

This multicentre investigation presents the largest cohort study to date analysing salivary gland tumour data from tertiary centres scattered across the globe. These findings should serve as a baseline for future studies evaluating the epidemiological landscape of these tumours.

Establishment of prognostic nomogram for high-grade parotid gland mucoepidermoid carcinoma based on the SEER database

Purpose: We aim to investigate the clinical factors that affect the prognosis of overall survival (OS) for patients with high-grade parotid gland mucoepidermoid carcinoma (high-grade pMEC) and construct a nomogram for prognosis prediction. Subjects and method: Totally, 519 patients diagnosed as high-grade pMEC from the surveillance, epidemiology, and end results (SEER) database between 2004 and 2015 were reviewed. Independent prognostic factors for OS were identified by univariate and multivariate Cox regression analyses. Nomogram was generated to predict the individual's 3- and 5- year OS rates by using R software. Prediction ability was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC) and model calibration was evaluated through calibration plots. Decision curve analysis (DCA) was used to assess the clinical usefulness and net benefit. Results: The results of univariate analysis demonstrated that age, AJCC stage, T stage, N stage, M stage, extraparenchymal lesions, regional lymph nodes status, lymph node dissection status, radiotherapy, chemotherapy, and surgery were significantly correlated with the OS (P < 0.05). Multivariate Cox regression analyses showed that older age at diagnosis, advanced AJCC stage, and positive regional lymph nodes were independent risk factors for OS. In addition, the present study revealed that radiotherapy and surgery were independent protective factors for OS (P < 0.05). The nomograms showed accurate prognostic ability that individually predict 3-years and 5-years overall survival (OS) rates based on age, AJCC stage, regional lymph nodes status, radiotherapy, and surgery. The area under the receiver operating characteristic (ROC) curve (AUC) of the nomogram used to predict the 3-year and 5-year overall survival rate were 0.779 and 0.793, indicating that the model had a good predictive power for the overall survival in high-grade pMEC patient. Conclusions: Using the SEER database, we performed univariate and multivariate analyses to determine independent prognostic factors in high-grade pMEC patients. Subsequently, we constructed and validated a prognostic nomogram to predict 3-and 5-year OS rates based on the SEER database and can assist clinicians to intuitively evaluate prognosis of high-grade pMEC patients.

Establishment of a patient‑derived mucoepidermoid carcinoma cell line with the CRTC1‑MAML2 fusion gene

Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of the major and minor salivary glands. Surgical resection is the only curative treatment and there is no effective post-operative therapy for MEC. The present study reports an Institutional Review Board-approved case of a 45-year-old Japanese female diagnosed with low-grade MEC in the hard palate. Radical resection, supraomohyoid neck dissection and antero-lateral thigh flap reconstruction was performed. A MEC cell line was then established from the resected tumor tissue. Short tandem repeat profiling confirmed the origin and authenticity of the cell line, that harbors a CRTC1-MAML2 translocation, which is frequently observed in MEC. Amphiregulin (AREG), identified as one of the targets of the CRTC1-MAML2 fusion gene, was expressed in the cell line. The AREG receptor, epidermal growth factor receptor (EGFR) was also highly phosphorylated. The results predicted that AREG-EGFR signaling, which is required for tumor growth and survival, might be activated in the cell line in a cell-autonomous manner. As AREG expression is associated with EGFR-targeted drug resistance, this cell line might assist with the identification of novel strategies for MEC treatment.

Adenoid cystic carcinoma of the sublingual gland developing lung metastasis 20 years after primary treatment: A case report and literature review

RATIONALE

Adenoid cystic carcinoma (ACC) is a rare malignant tumor that primarily occurs in the salivary glands. Distant metastases can develop despite favorable local control. Moreover, distant metastasis of ACC can occur after a long time interval without local recurrence. We report the first case of ACC of the sublingual gland that developed lung metastasis 20 years after primary treatment.

PATIENT CONCERNS

A 52-year-old man was referred to our department with a 1-year history of painful swelling on the right oral floor.

DIAGNOSIS

An incisional biopsy was performed, and histopathological examination revealed malignancy.

INTERVENTIONS

Surgical excision of the right oral floor and right supra-omohyoid neck dissection with postoperative chemoradiation therapy were performed, and ACC of the sublingual gland was diagnosed. Left pulmonary metastasis was detected 20 years after the primary treatment. Metastasectomy was performed; however, subsequently, skin and bone metastases developed.

OUTCOMES

After receiving palliative care, the patient died of multiple organ failure.

LESSONS

As late distant metastasis of salivary ACC can develop, patients who undergo primary treatment need a long-term, strict follow-up plan even if locoregional control is favorable.

A Synopsis of Signaling Crosstalk of Pericytes and Endothelial Cells in Salivary Gland

The salivary gland (SG) microvasculature constitutes a dynamic cellular organization instrumental to preserving tissue stability and homeostasis. The interplay between pericytes (PCs) and endothelial cells (ECs) culminates as a key ingredient that coordinates the development, maturation, and integrity of vessel building blocks. PCs, as a variety of mesenchymal stem cells, enthrall in the field of regenerative medicine, supporting the notion of regeneration and repair. PC-EC interconnections are pivotal in the kinetic and intricate process of angiogenesis during both embryological and post-natal development. The disruption of this complex interlinkage corresponds to SG pathogenesis, including inflammation, autoimmune disorders (Sjögren’s syndrome), and tumorigenesis. Here, we provided a global portrayal of major signaling pathways between PCs and ECs that cooperate to enhance vascular steadiness through the synergistic interchange. Additionally, we delineated how the crosstalk among molecular networks affiliate to contribute to a malignant context. Additionally, within SG microarchitecture, telocytes and myoepithelial cells assemble a labyrinthine companionship, which together with PCs appear to synchronize the regenerative potential of parenchymal constituents. By underscoring the intricacy of signaling cascades within cellular latticework, this review sketched a perceptive basis for target-selective drugs to safeguard SG function.

Head-and-Neck Solid Tumors in Children: A Retrospective Review from a Tertiary Care Institute in North India

Objectives

The aim of this study was to review the clinical profile, management, and outcome of solid tumors in the head-and-neck region in children at our institute.

Methods

We retrospectively reviewed children with head-and-neck solid tumors who were treated jointly under the departments of Pediatric Surgery and Otorhinolaryngology at our institute between 2016 and 2019.

Results

In the study period, 10 children (6 males, 4 females) with a median age of 9.5 years (range 5 days-16 years) were treated by our unit. The patients had four tumors arising from the parotid, 2 from nose/naso-pharynx, 1 each from the tongue, submandibular gland, para-pharyngeal space, and infratemporal fossa. A majority (90%) of the patients underwent complete surgical excision of the tumor, preserving the loco-regional neurovascular structures to minimize postoperative morbidity. Malignant lesions were seen in 4 patients (2 rhabdomyosarcoma, 1 primitive neuro-ectodermal tumor, 1 mucoepidermoid carcinoma) and 6 patients had benign pathology (3 pleomorphic adenoma, 2 mature teratoma, 1 schwanomma). Additional therapy with chemotherapy and local radiotherapy was required in 3 out of 4 patients with malignant pathology. The median follow-up duration is 15 months. At last follow-up, all patients are alive and 9 out of 10 patients (90%) are disease-free.

Conclusion

Our experience highlights rare and difficult tumors in the head-and-neck region in children. These tumors are not commonly managed by the pediatric surgeon in routine practice. The paper outlines the multi-modality management of these tumors, which is essential for an optimal outcome.

A Rare Case of Brain Metastasis from Dedifferentiated Acinic Cell Carcinoma of the Parotid Gland and Review of the Literature

Acinic cell carcinoma (ACC) is a low or intermediate-grade malignant epithelial neoplasm of the salivary glands that generally shows an indolent behavior. Most cases arise in the major salivary glands, especially the parotid gland. ACC is usually known as a low-grade malignant tumor; however, poorly differentiated and high-grade transformed variants have been reported and may tend to be late recurrence and metastasis. Our case was a 49-year-old woman with a history of a right parotid rapidly growing mass lesion, which was cytologically diagnosed as monomorphic adenoma on fine-needle aspiration (FNA). Finally, the diagnosis of ACC with dedifferentiated components was reported, followed by parotidectomy. After 30 sessions of radiotherapy, she presented with hemifacial paresis. An imaging examination of the brain showed intracranial hemorrhage, and she underwent a craniotomy. We performed histopathological and immunohistochemical (IHC) examinations and diagnosed metastatic ACC with dedifferentiated components. Few ACC cases with dedifferentiated components and with aggressive behavior have been reported in the literature , and to the best of our knowledge, this article is the first English report in Iranian population.

Deep Learning for Differentiating Benign From Malignant Parotid Lesions on MR Images

Purpose/Objectives(s)

Salivary gland tumors are a rare, histologically heterogeneous group of tumors. The distinction between malignant and benign tumors of the parotid gland is clinically important. This study aims to develop and evaluate a deep-learning network for diagnosing parotid gland tumors via the deep learning of MR images.

Materials/Methods

Two hundred thirty-three patients with parotid gland tumors were enrolled in this study. Histology results were available for all tumors. All patients underwent MRI scans, including T1-weighted, CE-T1-weighted and T2-weighted imaging series. The parotid glands and tumors were segmented on all three MR image series by a radiologist with 10 years of clinical experience. A total of 3791 parotid gland region images were cropped from the MR images. A label (pleomorphic adenoma and Warthin tumor, malignant tumor or free of tumor), which was based on histology results, was assigned to each image. To train the deep-learning model, these data were randomly divided into a training dataset (90%, comprising 3035 MR images from 212 patients: 714 pleomorphic adenoma images, 558 Warthin tumor images, 861 malignant tumor images, and 902 images free of tumor) and a validation dataset (10%, comprising 275 images from 21 patients: 57 pleomorphic adenoma images, 36 Warthin tumor images, 93 malignant tumor images, and 89 images free of tumor). A modified ResNet model was developed to classify these images. The input images were resized to 224x224 pixels, including four channels (T1-weighted tumor images only, T2-weighted tumor images only, CE-T1-weighted tumor images only and parotid gland images). Random image flipping and contrast adjustment were used for data enhancement. The model was trained for 1200 epochs with a learning rate of 1e-6, and the Adam optimizer was implemented. It took approximately 2 hours to complete the whole training procedure. The whole program was developed with PyTorch (version 1.2).

Results

The model accuracy with the training dataset was 92.94% (95% CI [0.91, 0.93]). The micro-AUC was 0.98. The experimental results showed that the accuracy of the final algorithm in the diagnosis and staging of parotid cancer was 82.18% (95% CI [0.77, 0.86]). The micro-AUC was 0.93.

Conclusion

The proposed model may be used to assist clinicians in the diagnosis of parotid tumors. However, future larger-scale multicenter studies are required for full validation.

Epidemiology of Primary Epithelial Salivary Gland Tumors in Southern Poland-A 26-Year, Clinicopathologic, Retrospective Analysis

(1) Background: Epidemiological studies of epithelial salivary gland neoplasms are difficult to conduct effectively due to tumor rarity, histological heterogeneity, tumor location diversity, and a lack of national registries collecting data. This study presents 26 years of epidemiological data from a single institution in southern Poland that estimates incidence rates of primary epithelial salivary gland tumors. (2) Methods: The charts of 805 patients with epithelial salivary gland tumors were retrospectively reviewed. (3) Results: Pleomorphic adenomas occurred less frequently in elderly patients; however, Warthin tumors were more common (p < 0.001). Pediatric patients mainly suffered from mucoepidermoid carcinoma. The estimated crude and European age-standardized incidence rates of all primary epithelial salivary gland tumors were 6.7 and 6.02 per 100,000 population, respectively. The incidence rates of salivary gland tumors increased in recent years; however, this is attributed to an increase in benign tumors (p < 0.001). (4) Conclusions: The incidence of primary epithelial salivary gland tumors in southern Poland has increased over the past 26 years. This increase is attributed to a rise in the number of patients with benign tumors, particularly Warthin tumors in elderly patients. Moreover, the incidence of malignant salivary gland tumors appears to be higher in pediatric patients.

Magnetic resonance imaging of salivary gland tumours: Key findings for imaging characterisation

Salivary gland tumours are rare, representing only 3% of all head and neck neoplasms, with the parotid gland being the most common site (80 %). The risk of malignancy is inversely proportional to the size of the gland: lesions arising in the sublingual or minor salivary glands are more likely to be malignant, whereas parotid gland neoplasms are mostly benign. Fine needle aspiration cytology and core needle biopsy are considered the most accurate modalities for the diagnosis of a salivary gland neoplasm; however, they are not always conclusive due to procedural sampling errors and for the presence of a cytological / histological overlap between benign and malignant tumours. Moreover, they cannot be easily performed for parotid deep portion localisation. The role of magnetic resonance imaging (MRI) is growing and advanced techniques (diffusion-weighted and dynamic contrast-enhanced perfusion-weighted imaging) can provide useful additional information for the assessment of salivary gland neoplasms. The aim of this review is to present the main MRI and clinical features of salivary gland tumours to improve their comprehensive evaluation and characterisation.

Clinical Utility of Qualitative Elastography Using Acoustic Radiation Force Impulse for Differentiating Benign from Malignant Salivary Gland Tumors

The goal of the work described here was to evaluate the utility of acoustic radiation force impulse (ARFI) imaging, a novel elastography technique, for differentiating benign from malignant salivary gland tumors. With the use of conventional strain elastography (SE) and ARFI imaging with a four-pattern scoring system, 185 tumors were examined (163 benign/22 malignant). When a score of ≥3 was used to define malignancy, the sensitivity, specificity and accuracy were higher for ARFI imaging (77.3%, 63.8% and 65.4%, respectively) than for conventional SE (54.5%, 56.4% and 56.2%, respectively). ARFI imaging findings revealed that most (92%) Warthin tumors, but only 24% of pleomorphic adenomas, were benign (score: 1 or 2). Attenuation of acoustic push pulses made it difficult to determine the stiffness of malignant tumors in the deep parotid lobes. Thus, ARFI imaging is a useful tool for screening Warthin tumors and exhibits high sensitivity for malignant tumors of salivary glands, other than deep parotid lobe tumors.

Incidence and profile of benign epithelial tumors of salivary glands from a single center in Northeast of Brazil

Background

Benign tumors of the salivary glands are a group of lesions with varied histopathological and clinical spectrum. The aim was to determine the incidence and clinicopathological characteristics of benign salivary gland neoplasms diagnosed between 2007 and 2016 in a single center located in northeastern Brazil.

Material and Methods

Records regarding sex, age, anatomical location, histopathological subtype and treatment were retrieved, and data were analyzed using the Stata/IC software (version 12.0).

Results

There were above 7,100 cases of neoplasms in the head and neck region, of which 403 corresponded to salivary gland neoplasms. Of these, 238 (59%) were benign, being pleomorphic adenoma (PA) the most frequent neoplasm (n=178; 74.8%), followed by Warthin's tumor (WT) (n=23; 9.7%). Overall, most cases occurred in females (n=136; 57.1%) and age ranged from 11 to 83 years. The parotid gland (n=188; 79%) was the most common anatomical site, and all patients were treated by surgical excision. Of the cases diagnosed as PA, malignant transformation to carcinoma ex-pleomorphic adenoma (CAEXPA) occurred in 7 (3.9%) cases.

Conclusions

The present study confirmed the clinical and demographic profile of benign salivary gland neoplasms, which contributes to the continuous knowledge of current data about these lesions.

Key words:Salivary gland, benign neoplasms, epidemiology.

Tumors of the labial mucosa: a retrospective study of 1045 biopsies

BACKGROUND

To investigate the relative frequency of localized mucosal swellings of the upper and lower labial mucosa, the clinical-pathological diagnosis agreement and whether patient's age and gender and tumor's site and size may raise the suspicion of neoplasm.

MATERIAL AND METHODS

Retrospective analysis was performed on upper or lower labial mucosal tumors, histopathologically diagnosed between 2009-2018. The diagnostic categories developmental/reactive tumors, benign and malignant neoplasms were associated with patient's age and gender and tumor's site and size; clinical-pathological diagnosis agreement was, also, evaluated.

RESULTS

Overall, 1000 (95.7%) developmental/reactive tumors, 35 (3.3%) benign and 10 (1%) malignant neoplasms were found. Upper/lower lip tumor ratio was 0.14:1. The diagnostic category was significantly associated with age (p<0.0001), site (p<0.0001) and diameter (p<0.0001). Age ≥60 years, tumor's location on the upper lip and diameter >1cm were independent predictors for neoplasms. Patients presenting 2 or 3 of these variables were 20.2 times (p < 0.0001) or 33.6 times (p < 0.0001), respectively, more likely to have a neoplasm. Complete/partial agreement between clinical and pathological diagnosis was seen in 96.3% of the cases.

CONCLUSIONS

Most lip tumors involve the lower lip and are reactive, but upper lip tumors measuring >1cm in patients≥60 years have significantly higher probability to be neoplasms.

Parotid Gland Tumors in Northern Greece: A 7-year Retrospective Study of 207 Patients

&lt;b&gt;Introduction:&lt;/b&gt; Parotid gland neoplasms represent a heterogenous group of tumors, either benign or malignant. The diagnosis and management of parotid gland tumors is complicated by their relative infrequency and their diverse biologic behavior. &lt;br&gt;&lt;b&gt;Aim:&lt;/b&gt; The aim of this study is to investigate the epidemiological characteristics, the recurrence rates and the surgical approach employed for parotid gland tumors in Northern Greece. &lt;br&gt;&lt;b&gt;Material and methods:&lt;/b&gt; This is a single-center retrospective study. All patients admitted to the ENT department of "G. Papanikolaou" General Hospital of Thessaloniki from January 2012 to June 2019 with the diagnosis of parotid gland tumor were included in the study. Patients with incomplete charts and patients that underwent revision surgeries were excluded. Chi-squared tests were used to assess the associations between variables. &lt;br&gt;&lt;b&gt;Results:&lt;/b&gt; A total of 207 patients with a mean age of 54.97 (range 16-91) were included in the study. Benign neoplasms accounted for 87.9% of the cases. Warthin's tumor was the most common neoplasm encountered, with an incidence of 46.8%, followed by pleomorphic adenoma (31.9%). There was a higher incidence of parotid gland tumors in males and smokers (P = 0.025, P = 0.001 respectively). The majority of the patients were treated with an extracapsular resection (60.4%) or with a partial superficial parotidectomy (22.6%). In 12 cases (5.7%), there was a recurrence of the lesion. The most common complications encountered were facial nerve injury, Frey's syndrome and hematoma formation. &lt;br&gt;&lt;b&gt;Conclusions:&lt;/b&gt; Parotid gland tumors are typically benign, non-aggressive tumors, more frequently seen in men than women. There is a positive association between smoking and parotid gland tumor development. Comprehensive information regarding recurrence and complication rates is presented.

The Impact of Angiogenesis in the Most Common Salivary Gland Malignant Tumors

Salivary gland carcinomas (SGCs) represent a group of rare tumors, with complete surgical resection being the main treatment option. Therapeutic armory for cases of locally aggressive, recurrent, and/or metastatic SGCs, though, remains poor since they exhibit high rates of resistance to systematic therapy. Angiogenesis is considered one of the contemporary hallmarks of cancer and anti-angiogenic factors have already been approved for the treatment of several cancer types. This review aims to summarize, in a histotype-specific manner, the most current available data on the angiogenic factors implicated in SGC angiogenesis, in order to highlight the differences between the most common SGC histotypes and the factors that may have a potential role as therapeutic targets.

Salivary gland tumours in Iceland 1986-2015: a nationwide epidemiological analysis over a 30-year time period

Salivary gland tumours (SGT) are a vast and heterogenous group of neoplasms. There is a relative lack of comprehensive nationwide epidemiological studies on the subject. The aim of this nationwide analysis was to gain insight into epidemiological traits, such as site, incidence and histological subtypes of SGT in general. Patients diagnosed with a primary SGT between 1986 and 2015 were identified from The Icelandic Cancer Registry and registries from all pathology departments in Iceland. Information on age, sex, tumour location and histology was retrieved from pathology reports. A total of 687 patients were diagnosed with a SGT, 609 (89%) were benign and 78 (11%) malignant. 9% of parotid gland tumours, 22% of submandibular gland tumours and 26% of minor SGT were malignant. The most common malignant tumours were mucoepidermoid carcinoma, acinic cell carcinoma and adenoid cystic carcinoma. The incidence of benign SGT was 4.9 per 100 000 among men and 7.0 per 100 000 among women. The incidence of malignant tumours was 0.59 per 100 000 for men and 0.79 per 100 000 for women. The proportion of malignant SGT is lower than most often reported. Only 10% of parotid gland tumours, 20% of submandibular gland tumours and 25% of minor salivary gland tumours are malignant.

Salivary Gland Tumors: A Retrospective Study of 164 Cases from a Single Private Practice Service in Mexico and Literature Review

Salivary gland tumors (SGT) represent an uncommon heterogeneous group of tumors with complex clinical and pathological characteristics. The prevalence of these lesions varies between studies but has been estimated between 3 and 6% of all tumors in the head and neck region. The present study aimed to evaluate the distribution and demographic findings of salivary gland tumors diagnosed in an oral pathology service in Mexico. A retrospective descriptive cross-sectional study was performed. A total of 164 cases of SGT from a private oral pathology service were diagnosed between 2000 and 2019 in Mexico City. All cases were reviewed histologically, and demographic data and histopathological diagnoses were collected. A total of 110 (67.1%) tumors were benign, and 54 (32.9%) were malignant. The majority of patients were female (n = 100, 61.0%) with an overall female:male ratio of 1.6:1. The minor salivary glands were affected more than the major salivary glands (68.9% vs. 25.6%). The palate (n = 67, 40.9%) was the most commonly affected site, followed by the parotid gland (n = 37, 22.6%), lips (n = 16, 9.8%), and buccal mucosa (n = 14, 8.5%). Pleomorphic adenoma (n = 88; 80.0%) and mucoepidermoid carcinoma (n = 16, 29.6%) were the most frequent benign and malignant tumors, respectively. The general features of SGT from the studied Mexican population shared some similarities and differences compared to previously reported series from various parts of the world.

Salivary gland neoplasms: A 10-year review of a major referral center in Ghana

OBJECTIVE

The aim of this study was to describe the clinicopathologic features of salivary gland tumors (SGTs) that were managed at a major referral center in Ghana.

STUDY DESIGN

This was a retrospective study of all histologically diagnosed and managed Ghanaian patients with SGTs during the period January 2008 to December 2017. Information collected included age, gender, affected gland, presenting symptom, treatment modality, histologic diagnosis, and complications. Descriptive summaries of variables were generated. The χ² test with Fisher's test was used to compare categorical variables with subsequent testing of association.

RESULTS

The study included 116 patients, with 49 males (42.2%) and 67 females (57.8%), representing a ratio of 1:1.4. There were 82 (70.7%) benign SGTs and 34 (29.3%) malignant SGTs. The most common benign SGT was pleomorphic adenoma, which accounted for 62.1% of all SGTs. Malignant SGTs occurred more in older people, and the occurrence of SGTs was significantly at a lower age in males compared with females.

CONCLUSIONS

Although the general pattern of SGTs did not seem to differ significantly in comparison with the findings of a review performed 10 years earlier, the findings of this study could inform hypotheses generation for future studies to explore the risk factors and associations peculiar to the Ghanaian environment.

Analyses of cancer incidence and other morbidities in gamma irradiated B6CF1 mice

With increasing medical radiation exposures, it is important to understand how different modes of delivery of ionizing radiation as well as total doses of exposure impact health outcomes. Our lab studied the risks associated with ionizing radiation by analyzing the Northwestern University Radiation Archive for animals (NURA). NURA contains detailed data from a series of 10 individual neutron and gamma irradiation experiments conducted on over 50,000 mice. Rigorous statistical testing on control mice from all Janus experiments enabled us to select studies that could be compared to one another and uncover unexpected differences among the controls as well as experimental animals. For controls, mice sham irradiated with 300 fractions died significantly earlier than those with fewer sham fractions and were excluded from the pooled dataset. Using the integrated dataset of gamma irradiated and control mice, we found that fractionation significantly decreased the death hazard for animals dying of lymphomas, tumors, non-tumors, and unknown causes. Gender differences in frequencies of causes of death were identified irrespective of irradiation and dose fractionation, with female mice being at a greater risk for all causes of death, except for lung tumors. Irradiated and control male mice were at a significantly greater risk for lung tumors, the opposite from observations noted in humans. Additionally, we discovered that lymphoma deaths can occur quickly after exposures to high doses of gamma rays. This study systematically cross-compared outcomes of different modes of fractionation evaluated across different Janus experiments and across a wide span of total doses. It demonstrates that protraction modulated survival and disease status differently based on the total dose, cause of death, and sex of an animal. This novel method for analyzing the Janus datasets will lead to insightful new mechanistic hypotheses and research in the fields of radiation biology and protection.

Prevalence of mucoepidermoid carcinoma among intraoral minor salivary gland tumors: A systematic review and meta-analysis

This study aimed to synthetize and critically appraise available evidence regarding mucoepidermoid carcinoma (MEC) prevalence among intraoral minor salivary gland tumors (MiSGT). Five main electronic databases and three grey literature databases were searched. The risk of bias (RoB) was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data. Proportion meta-analyses were performed. From 1321 studies identified, 82 were included in qualitative synthesis and 80 in meta-analyses. Sixteen were classified as high, 33 as moderate, and 33 as low RoB. A total of 12 774 MiSGT were found, of which overall MEC prevalence was 16.5% (95% Confidence Interval [95% CI] = 14.8%-18.4%). Most MiSGT were found in the palate (n = 7115), although MEC pooled prevalence in this anatomic location was only 13.6% (95% CI = 11.7%-15.6%). The retromolar area presented the highest pooled prevalence (58.9%; 95% CI = 47.0%-70.3%), followed by gingiva (28.8%; 95% CI = 22.7%-35.4%) and tongue (27.2%; 95% CI = 21.2%-33.6%). Regarding geographic location, Middle East presented the highest pooled prevalence (20.8%; 95% CI = 14.8%-27.6%), followed by America (20.0%, 95% CI = 17.2%-23%) and Europe (15.6%; 95% CI = 9.2%-23.5%). Among MiSGT, the MEC overall prevalence was approximately 16.5%. Although most MiSGT were found in the palate, the retromolar area was proportionally more affected by MEC.

Salivary gland tumors: A 15-year experience of a university hospital in Turkey

OBJECTIVE:

To determine the demographic characteristics of benign and malignant salivary gland tumors in our department in the last 15 years.

METHODS:

In this study, the files of the patients who underwent salivary gland surgery between 2004 and 2019 in our department were analyzed retrospectively. A total of 366 patients whose diagnoses of salivary gland tumor histopathologically confirmed were included in this study. The demographic data of the patients and tumor localizations were recorded, and their relationships with histopathological results were examined.

RESULTS:

Of the 366 tumors, 292 (80%) of them was originated from the parotid gland, 52 (14%) from the submandibular gland, and 22 (6%) from the minor salivary gland. The male: female ratio was found as 1.2:1, and the mean age of the patients was 50.37 years. A total of 259 (70.8%) tumors were benign, and 107 (29.2%) were malignant. The most frequent benign tumor was pleomorphic adenoma, with 121 cases (46.7%). While pleomorphic adenomas constituted the majority of the benign tumors of the submandibular gland and minor salivary glands, Warthin tumor was detected more than pleomorphic adenoma in the parotid gland. The most common malignant tumor was mucoepidermoid carcinoma, with 26 cases (24.3%).

CONCLUSION:

The distribution of the salivary gland tumors detected in our department was found to be substantially similar to other worldwide series. Unlike the literature, we concluded that salivary gland tumors were seen slightly more in males, minor salivary gland tumors were relatively rare and Warthin tumors were more frequently detected in our region.

Review and characteristics of 585 salivary gland neoplasms from a tertiary hospital registered in the Polish National Major Salivary Gland Benign Tumors Registry over a period of 5 years: a prospective study

&lt;b&gt;Introduction:&lt;/b&gt; A Polish National Major Salivary Gland Benign Tumors Registry (SGR) is a report of benign salivary gland neoplasms (SGNs) from 26 different centres in Poland, introduced in 2014. The aim of this study is to analyze demographic characteristics and clinico-pathological factors of benign SGNs treated in large tertiary institutions and to determine possible correlations between selected variables. &lt;br&gt;&lt;b&gt;Material and method:&lt;/b&gt; Analysis of 585 patients recorded in SGR and operated on for SGNs in the Department of Otolaryngology and Laryngological Surgery, University of Medical Sciences, Poznań, Poland, over a 5-year period. Patient age, sex, occupation, place of residence, tumor location, size, histology, recurrence, facial nerve function after surgery, wound healing, surgery procedure, availability of pre-operative imaging examinations, fine-needle aspiration cytology (FNAC) results were analyzed. &lt;br&gt;&lt;b&gt;Results:&lt;/b&gt; 338 females and 247 males with a mean age of 53 years were operated on. In total, 96.2% of tumors originated from the parotid and 3.8% from the submandibular gland. The most frequent primary tumor diameter was 2-4 cm (59.5%) followed by &lt;2 cm (29.2%) and &gt;4 cm (8.4%). Tumors of over 4 cm were frequently removed by partial superficial parotidectomy, while those under 2 cm - by extracapsullar dissection (ECD). Pleomorphic adenomas (PA) were predominant (58.8%), followed by Warthin's tumor (WT) - 37.1%. Patients with WT were on average 13.3 years older than patients with PA. &lt;br&gt;&lt;b&gt;Discussion:&lt;/b&gt; This research can be helpful to better understand the clinico-pathological features of SGNs. Long-termin hospital-based analysis is important for subsequent metaanalyses and comparisons with other centers. The reasons why not all patients' data are reported to the national SGR should be further precisely analyzed.

Accuracy of combined quantitative diffusion-weighted MRI and routine contrast-enhanced MRI in discrimination of benign and malignant salivary gland tumors

BACKGROUND

Preoperative imaging of salivary gland tumors is important for predicting and differentiating benign from malignant tumors, and for aiding management planning. We aimed to investigate the accuracy of combined quantitative diffusion-weighted magnetic resonance imaging (MRI) and routine contrast-enhanced MRI in the evaluation of salivary gland tumors and the differentiation of benign from malignant tumors.

RESULTS

This study included 51 patients with a total of 16 benign and 35 malignant lesions that were detected by histopathological analysis. There was a statistically significant difference between the apparent diffusion coefficient values (ADC) of malignant and benign lesions (0.69 ± 0.22 × 10^-3 mm²/s and 1.39 ± 0.52 × 10^-3 mm²/s respectively). The optimal cut-off ADC value was 1.08 with 75% specificity and 97% sensitivity. The routine contrast-enhanced MRI had predicted benign and malignant tumors with 65% sensitivity and 44% specificity. The sensitivity and specificity were greatly increased when quantitative diffusion-weighted MRI was combined with routine contrast-enhanced MRI: 100%, and 88% respectively. A receiver operating curve was generated. The area under curve was 0.88 (p < 0.001, 95% CI: 0.76-0.99).

CONCLUSION

Combined quantitative diffusion-weighted MRI with ADC measurements and routine contrast-enhanced magnetic resonance imaging are helpful tools for the evaluation of salivary gland tumors and help differentiate benign from malignant lesions.

Retrospective study of 124 cases of salivary gland tumors and literature review

Background

Salivary gland tumors are a rare and morphologically diverse group of lesions and their frequency is still unknown in several parts of the world. The knowledge of its population characteristics contributes to a better understanding of its etiopathogenesis. Objectives: This study investigated the frequency of salivary gland tumors in a region of southern Brazil and compared these data in a literature review.

Material and Methods

A retrospective study was conducted of salivary gland tumors diagnosed at two pathology centers from 1995 to 2016. Patient age and gender, tumor site and frequency, histopathological diagnosis, and symptomatology were evaluated. Chi-squared tests were used to assess the associations between variables. To compare our data, we also conducted a literature review of publications in the PubMed and LILACS databases of retrospective studies of salivary gland tumors.

Results

A total of 124 salivary gland tumor cases was identified, 81 (65.3%) of which were classified as benign and 43 (34.6%) as malignant. Most tumors occurred in the parotid gland (57.2%). Pleomorphic adenoma was the most common tumor (59.6%), followed by adenocarcinoma not otherwise specified (8.8%). The tumors occurred more often in women (54.8%) than in men (45.2%). Malignant tumors were associated with pain in 31.4% of cases (p<0.05). The literature review included 35 articles from different countries. Women were most affected, with a mean age of 41.7 years. The most common benign tumor was pleomorphic adenoma (48.2%) and the most common malignant tumor was mucoepidermoid carcinoma (8.7%).

Conclusions

The results of the present study showed that salivary gland tumors are rare. The parotid gland is the most common location and pleomorphic adenoma are the most frequent lesions. The malignant tumors presented as several histological types and the incidence was variable globally. Key words:Salivary gland neoplasms, salivary gland diseases, oral surgery, epidemiology.

Clinical predictors of malignancy in palatal salivary gland tumors

OBJECTIVES

To establish a predictive clinical index of malignancy risk in palatal salivary gland tumors (PSGT).

MATERIALS AND METHODS

One hundred cases of PSGT were evaluated. Clinical data were retrieved from the patient's files. Representative clinical photographs of each tumor were evaluated to identify clinical features suggestive of a malignant tumor. Features significantly associated with malignancy were included in a binary logistic regression model.

RESULTS

Malignant tumors were more common in the hard palate, in women and in older patients. Features associated with a malignant diagnosis included pain (p = .017), irregular surface (p = .004), bluish/purple coloration (p < .001), ulceration (p = .005), and telangiectasia (p = .015). After multivariate logistic regression, pain (OR: 4.017; 95% CI: 1.198-13.471; p = .024) and color alteration (OR: 7.243; 95% CI: 2.068-25.363; p = .002) were independently associated with malignancy. Including these factors in a predictive index, the proportion of malignant tumors in patients presenting none, one and two factors were 25% (95% CI: 0.13-0.40), 67% (95% CI: 0.48-0.83), and 85% (95% CI: 0.42-0.99), respectively.

CONCLUSION

Pain and color alteration might be independent predictors of malignancy in PSGT, which could support the decision to perform an incisional or excisional biopsy.