Benign Salivary Gland Tumors Research Articles

A Case of Warthin Tumor Highlighting the Diagnostic Dilemmas Encountered

Introduction: Warthin’s tumour (WT) previously known as papillary cystadeno-lymphomatosum is the most frequent ‘monomorphic’ adenoma of the major salivary glands, representing about 2–15% of all parotid tumours. It is a benign epithelial salivary gland neoplasm affecting elderly individuals and commonly involves the inferior pole of parotid glands. Fine needle aspiration cytology is considered the first diagnostic approach for salivary gland lesions; however, the cytological findings in Warthin tumor can be dubious many a times.
 Case Presentation: We present a case of a female in sixth decade of life with left neck swelling which mimicked a necrotic lymph node on imaging and turned out to be Warthin tumor.
 Conclusion: In the present paper, we discuss the diagnostic dilemmas faced in a case of warthin tumor.

A deep learning model for the differential diagnosis of benign and malignant salivary gland tumors based on ultrasound imaging and clinical data.

The preoperative differentiation between benign parotid gland tumors (BPGTs) and malignant parotid gland tumors (MPGTs) is of great significance for therapeutic decision-making. Deep learning (DL), an artificial intelligence algorithm based on neural networks, can help overcome inconsistencies in conventional ultrasonic (CUS) examination outcomes. Therefore, as an auxiliary diagnostic tool, DL can support accurate diagnosis using massive ultrasonic (US) images. This current study developed and validated a DL-based US diagnosis for the preoperative differentiation of BPGT from MPGT. A total of 266 patients, including 178 patients with BPGT and 88 patients with MPGT, were consecutively identified from a pathology database and enrolled in this study. Ultimately, considering the limitations of the DL model, 173 patients were selected from the 266 patients and divided into 2 groups: a training set, and a testing set. US images of the 173 patients were used to construct the training set (including 66 benign and 66 malignant PGTs) and testing set (consisting of 21 benign and 20 malignant PGTs). These were then preprocessed by normalizing the grayscale of each image and reducing noise. Processed images were imported into the DL model, which was then trained to predict the images from the testing set and evaluated for performance. Based on the training and validation datasets, the diagnostic performance of the 3 models was assessed and verified using receiver operating characteristic (ROC) curves. Ultimately, before and after combining the clinical data, we compared the area under the curve (AUC) and diagnostic accuracy of the DL model with the opinions of trained radiologists to evaluate the application value of the DL model in US diagnosis. The DL model showed a significantly higher AUC value compared to doctor 1 + clinical data, doctor 2 + clinical data, and doctor 3 + clinical data (AUC =0.9583 vs. 0.6250, 0.7250, and 0.8025 respectively; all P<0.05). In addition, the sensitivity of the DL model was higher than the sensitivities of the doctors combined with clinical data (97.2% vs. 65%, 80%, and 90% for doctor 1 + clinical data, doctor 2 + clinical data, and doctor 3 + clinical data, respectively; all P<0.05). The DL-based US imaging diagnostic model has excellent performance in differentiating BPGT from MPGT, supporting its value as a diagnostic tool for the clinical decision-making process.

Head and Neck Tumor Histopathological Image Representation with Pr with Pre- Trained Conv ained Convolutional Neur olutional Neural Network and Vision al Network and Vision Transformer

Image representation via machine learning is an approach to quantitatively represent histopathological images of head and neck tumors for future applications of artificial intelligence-assisted pathological diagnosis systems. Objective: This study compares image representations produced by a pre-trained convolutional neural network (VGG16) to those produced by a vision transformer (ViT-L/14) in terms of the classification performance of head and neck tumors. Methods: Whole-slide images of five oral tumor categories (n = 319 cases) were analyzed. Image patches were created from manually annotated regions at 4096, 2048, and 1024 pixels and rescaled to 256 pixels. Image representations were classified by logistic regression or multiclass Support Vector Machines for binary or multiclass classifications, respectively. Results: VGG16 with 1024 pixels performed best for benign and malignant salivary gland tumors (BSGT and MSGT) (F1 = 0.703 and 0.803). VGG16 outperformed ViT for BSGT and MSGT with all magnification levels. However, ViT outperformed VGG16 for maxillofacial bone tumors (MBTs), odontogenic cysts (OCs), and odontogenic tumors (OTs) with all magnification levels (F1 = 0.780; 0.874; 0.751). Conclusion: Being more texture-biased, VGG16 performs better in representing BSGT and MSGT

An Investigation of the Clinico-histopathologic Trend of Salivary Gland Tumors in Amir Alam Hospital During 2010- 2019: A Retrospective Study

Background: The incidence and mortality rates of salivary gland tumors have increased according to previous evidence. No study has so far focused on the trend of clinical and histopathologic patterns of salivary gland tumors in Iran. Therefore, the aim was to investigate the incidence and clinico-histopathologic trend of salivary gland tumors in a retrospective, cross-sectional, institutional study from 2010-2019 in Amir Alam hospital. Methods: The archived medical records were collected from patients with the histopathologic diagnosis of benign and malignant salivary gland tumors from Amir Alam hospital, Tehran during (April-April) 2010- 2019. Demographic data and histopathologic features, including tumor size, lymph node involvement, vascular invasion, perineural involvement, and histopathologic differentiation were retrieved, and the samples were categorized and reviewed based on the new classification of head and neck tumors. Finally, the frequencies of characteristics were determined and expressed as numbers (percentage values). Results: Of 1203 salivary gland tumors, 77.6% and 22.4% were benign and malignant, respectively. The incidence of benign tumors was increased from 37 (22.2%) in 2010 to 178 (364.9%) in 2019. In the collection of the total samples, the incidence of malignant tumors was relatively steady from 23 (13.8%) samples in 2010 to 27 (55.35%) in 2019. However, an increase in the incidence of tumors with low-grade differentiation was found from 12.5% in 2010 to 80% in 2019. Conclusions: The incidence of benign and malignant salivary tumors with a higher degree of malignancy had an increasing trend in Amir Alam hospital during 2010-2019.

Uncommon case of cytopathological features of sialadenoma papilliferum.

Sialadenoma papilliferum, a benign and rare salivary gland neoplasm, accounts for 0.4%-1.2% of all salivary gland tumors and occurs primarily in minor salivary glands of the oral cavity. Here, we report a case of sialadenoma papilliferum and its associated cytological findings. A papillary tumor was incidentally detected on the palate of an 86-year-old Japanese man. Conventional oral exfoliative cytology was performed; the cytology smear exhibited epithelial clusters composed of atypical epithelial cells with a high nuclear/cytoplasm ratio and arranged in sheet or small papillary-like projections. Cytoplasmic vacuoles were also observed in the papillae. It was difficult to make a definitive diagnosis due to the presence of uncommon cytological features. The excisional biopsy specimen revealed histological features characteristic of sialadenoma papilliferum. Mutational analysis detected BRAFV600E mutation, which confirmed the diagnosis of sialadenoma papilliferum. To the best of our knowledge, no prior cytomorphological evaluations of sialadenoma papilliferum have been reported in detail. Oral exfoliative cytology specimens from salivary gland tumors can demonstrate uncommon cytomorphological features. A differential diagnosis of sialadenoma papilliferum can be based on the observation of mildly atypical epithelial cells that form small papillary-like structures.

Support Tools in the Differential Diagnosis of Salivary Gland Tumors through Inflammatory Biomarkers and Radiomics Metrics: A Preliminary Study

The purpose of this study was to investigate how the systemic inflammation response index (SIRI), systemic immune-inflammation index (SII), neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR), and radiomic metrics (quantitative descriptors of image content) extracted from MRI sequences by machine learning increase the efficacy of proper presurgical differentiation between benign and malignant salivary gland tumors. A retrospective study of 117 patients with salivary gland tumors was conducted between January 2015 and November 2022. Univariate analyses with nonparametric tests and multivariate analyses with machine learning approaches were used. Inflammatory biomarkers showed statistically significant differences (p < 0.05) in the Kruskal-Wallis test based on median values in discriminating Warthin tumors from pleomorphic adenoma and malignancies. The accuracy of NLR, PLR, SII, and SIRI was 0.88, 0.74, 0.76, and 0.83, respectively. Analysis of radiomic metrics to discriminate Warthin tumors from pleomorphic adenoma and malignancies showed statistically significant differences (p < 0.05) in nine radiomic features. The best multivariate analysis result was obtained from an SVM model with 86% accuracy, 68% sensitivity, and 91% specificity for six features. Inflammatory biomarkers and radiomic features can comparably support a pre-surgical differential diagnosis.

Efficacy of Ultrasound Shear Wave Elastography in the Diagnosis of Salivary Gland Tumors

Diagnostic accuracy of fine-needle aspiration cytology (FNAC) as the ability to discriminate between the target condition and health in the evaluation of salivary gland tumors is not perfected yet and false-negative results are possible. The purpose of the present study was to measure and compare the diagnostic accuracy of FNAC performed with conventional B-mode ultrasound and ultrasound with shear wave elastography (SWE) FNAC navigation. The investigators implemented a single-blind randomized study (sealed envelope method). The study population was composed of all patients presenting for evaluation and management of suspected benign or malignant tumors of the major salivary glands between July 2013 and December 2020. The involvement of SWE navigation was the primary predictor variable affecting FNA targeting. The method involved analysis of redistribution of SWE values within the affected gland expressed in kilopascals (kPa) and the four-point ES1 (soft tissue) to ES4 (stiff) scoring. The primary outcome variable was the success in obtaining diagnostic tissue resulting in a histologically confirmed FNAC diagnosis and coded as yes/no. Age and sex of the patients and topographical locations of lesions were covariates. Descriptive and bivariate statistics were computed and the P value was set at .05. The sample included 132 subjects (male/female 59/73; mean age 54±11years; 144 tumors). SWE+Group (n=66) consisted of patients presurgically diagnosed with salivary tumors SWE-guided FNAC and SWE- Group (n=66) was diagnosed with tumors by conventional ultrasound-(B-mode)-guided FNAC. The SWE-guided FNAC statistically significantly reduced the incidence of false-negative results (n=0; P=.001) and nondiagnostic cases (n=3 SWE FNAC vs n=7 B-mode US FNAC; P=.04). For SWE+Group, the FNAC diagnosis was confirmed by postsurgical histology in 95.5% with 91.0% sensitivity (confidence interval [CI] 0.62 to 0.97) and 84.4% specificity (CI 0.58 to 0.96). For SWE- Group, 81.8% confirmation was obtained (P=.05) with 82.3% sensitivity (CI 0.54 to 0.90) and 74.0% specificity. SWE can increase success in obtaining diagnostic tissue when used for FNAC navigation purposes. We suggest combining both SWE and standard B-mode US methods when the FNAC procedure is performed.

The diagnostic efficacy of ultrasonographically-based measurements of minimum and maximum fascia-tumor distance in differentiating superficial from deep lobe benign parotid tumors

The objective was to calculate the efficacy of ultrasonographically-based measurements of minimum and maximum fascia-tumor distance (MiFTD and MaFTD) of benign salivary gland tumors to identify tumor location in the superficial or deep lobe of the parotid gland. MiFTDs and MaFTDs were measured on pre-operative ultrasonographic images of 102 tumors. Tumor location was classified at surgery as superficial or deep based on relation to the facial nerve, with 74 tumors in the superficial lobe and 28 in the deep lobe. The diagnostic efficacy of differences in MiFTD and MaFTD between locations was calculated with the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. Statistical significance was established at P < .05. Mean MiFTD and MaFTD values were significantly smaller in the superficial lobe tumors than in the deep lobe lesions (P < .001). Tumors with cutoff values of MiFTD >2.7 mm or MaFTD >21.1 mm were considered deep lobe lesions. When using the cutoff values for both MiFTD and MaFTD, the AUC was 0.893, whereas sensitivity and specificity were .821 and .919, respectively. Ultrasonography can help in the preoperative localization of tumors in the superficial and deep lobes of the parotid gland. This can facilitate proper surgical treatment selection and minimize the risk of adverse consequences of facial nerve damage while improving cosmetic outcomes.

Insulin Like Growth Factor II mRNA-Binding Protein 3 (IMP3) Immunohistochemical Expression in Salivary Glands Tumors- Local Study

Objective: To identify the relationship between the expression of IMP3 in benign and malignant tumors of salivary glands and other clinic-pathological variables. Materials and Methods: Twenty-six cases of salivary gland tumors were collected from the histopathology department, Gazi-Hariri hospital/ Baghdad Medical City from January 2021 to June 2021. Patients’ reports were included for diagnosis and clinicopathological data. Three histological sections were taken from the paraffin blocks for each case. The first section was stained with H&amp;E stain, and the other two sections were stained with IMP3 (Dako-code M3626) monoclonal antibody by the immunohistochemical method. Results: Twenty-six cases of salivary gland tumor, with equal male/female distribution; the mean age for the patients was 45 years (19-60 years). There was no significant relationship between gender (P=.0.115), tumor size (P=0.359), tumor location (P=0.335), and tumor type (P=0.673) with positive expression of IMP3. Regarding malignant cases, no significant relation between IMP3 expression and tumor stage (P=1.000), and lymphovascular invasion (P=1.000). On the other hand, there was a highly significant relationship (P=0.000) between IMP3 expression and cell type (epithelial/mesenchymal). Conclusion: Imp3 might not be conclusive in differentiation between benign and malignant salivary gland tumors. Further studies with follow-up are needed to assess the prognostic value of this marker in salivary gland pathologies.

Malignancy rates of salivary gland tumors in Greenlandic Inuit comparable to non-endemic populations; epidemiological mapping of salivary gland tumors 1990–2019

BackgroundSalivary gland tumors are assumed to be predominantly malignant in the Greenlandic Inuit population, but there is limited literature on the subject. We conducted a retrospective cohort study using national registers to describe the histological tumor types, location, incidence, and survival of benign and malignant salivary gland tumors.MethodsWe analyzed data on all Greenlandic Inuit with an epithelial-derived salivary gland tumor from 1990 to 2019. We extracted data from the Central Personal Registry and crossmatched it with the Danish Pathology Data Bank. All specimens were reviewed by a specialized pathologist. We noted patient and histological characteristics, calculated crude and age-adjusted incidence rates, overall survival, and excess mortality.ResultsOur study found that 76% of salivary gland tumors in the Greenlandic Inuit population were benign, with pleomorphic adenoma being the most common. Malignant tumors accounted for 24% of cases, with lymphoepithelial carcinoma being the most common type. The most common place of origin for malignant tumors was the parotid gland (71%) and the submandibular gland (15%). The median age of onset for malignant tumors was 47 years. Age-adjusted incidence rates of malignant tumors for men and women were 3.00 and 4.12 per 100,000 person-years, respectively.ConclusionOur findings suggest that the proportion of malignant salivary gland tumors in the Greenlandic Inuit population is similar to other nonendemic populations. Our incidence rates are higher than previously reported, likely due to differences in methodology and definitions of the Inuit population. This study provides valuable insights into the epidemiology of salivary gland tumors in the Greenlandic Inuit population and may have implications for other Inuit populations as well.

Oncocytic Papillary Cystadenoma, an Unusual Variant Presenting as a Laryngeal Ventricular Cyst.

Cystadenoma arising from the larynx is a rare benign minor salivary gland tumor that can show mucinous or papillary morphology. The epithelial lining of the salivary gland tumor can present with oncocytic features, which is attributed to an increased number of mitochondria. We present a rare case of oncocytic papillary cystadenoma (OPC) of the larynx which has a combination of these features. The WHO defines OPC tumors as entities which closely resemble Warthin tumor, but lack its classic lymphoid component. The immunohistochemical profile and molecular genetic features are largely unknown. We present an 84-year-old female, former smoker, who presented with progressive dysphonia, dysphagia, and shortness of breath. Laryngoscopy revealed a large, smooth mass originating from the ventricle of the right vocal fold. Subsequent biopsy demonstrated cyst wall fragments lined by a bilayer of large columnar to cuboidal oncocytic cells that had granular eosinophilic cytoplasm, round to oval nuclei with finely dispersed chromatin, and small but distinct nucleoli. The surrounding stroma was slightly fibrotic with scant lymphoid elements. No nuclear pleomorphism, increased mitosis, or necrosis was identified. In the larynx, benign salivary gland tumors are rare and less frequent than malignant neoplasms. Awareness of rare benign entities like OPC help ensure proper management and aid in avoiding unnecessary therapy.

Pleomorphic Adenoma of Nasal Septum a Case Report

IntroductionPleomorphic adenoma is a common benign tumor of large and small salivary glands. It mainly occurs in the parotid gland, followed by the submandibular gland, sublingual gland and small salivary gland in the oral cavity. It is very rare in the nasal septum.Patient ConcernsA 27-year-old female patient attended our clinic with Nasal congestion and a diminished sense of smell.DiagnosesEndoscopic examination revealed a mass within the right nasal passage. A pathological biopsy revealed pleomorphic adenoma.InterventionsThe nasal septum pleomorphic adenoma was resected by endoscopic approach.OutcomesNo recurrence was observed for over 41 months of follow-up.ConclusionTo prevent recurrence, extensive local resection with clear histological margins and long-term endoscopic follow-up with an endoscope are necessary.

Common Tumor in an uncommon location: Pleomorphic Adenoma of nasal cavity - a case Report.

Pleomorphic adenoma (PA) is the most common benign salivary gland tumor of which parotid gland involvement is the most common. PA may arise from minor salivary glands as well, however, PA is very rare in the sinonasal and nasopharyngeal areas. It usually affects middle aged females. They are frequently misdiagnosed due to high cellularity and myxoid stroma, leading to delay in diagnosis & further appropriate management. Here we present a case report of a female who presented with gradually progressive nasal obstruction, on examination found to have a nasal mass in right nasal cavity. Imaging was done and the nasal mass was excised. Histopathological report revealed a PA. Common tumor in an uncommon location: Pleomorphic adenoma of the nasal cavity - a case report.

WT1 as a myoepithelial marker: a comparative study of breast, cutaneous, and salivary gland lesions

WT1 immunostain is expressed in various benign and malignant neoplasms, as well as normal myoepithelial cells. WT1 shows differential expression in non-neoplastic, benign, and malignant neoplastic myoepithelial cells of the salivary gland. In this study, WT1 immunostain and other myoepithelial markers were compared to investigate the value of WT1 as a myoepithelial marker, and to delineate the expression profile of WT1 in nonsalivary gland myoepithelial cells. WT1, p63, and calponin immunostains were performed on normal and lesional tissues from the breast (adenosis, sclerosing adenosis, lactating adenoma, nipple adenoma, tubular adenoma, adenomyoepithelioma, and adenoid cystic carcinoma [ACC]), skin (cutaneous mixed tumor, hidradenoma, spiradenoma, and ACC), and salivary gland (pleomorphic adenoma and ACC). The stained slides were digitized and orientated with H&E images and assessed simultaneously using QuPath. A total of 129, 58, and 56 breast, cutaneous, and salivary gland lesions, respectively, were included. There was poor agreement between WT1-p63 and WT1-calponin (κ<0.1) in all organs, with absence of WT1 expression in normal salivary gland myoepithelium and most ACCs. There were no significant differences in WT1 expression in myoepithelial cells in normal breast tissue and benign breast neoplasms. Compared to pleomorphic adenomas, cutaneous mixed tumors showed lower WT1 expression (P<.001). WT1 is a less sensitive myoepithelial marker than calponin and p63. However, its unique pattern of expression in salivary gland primary for pleomorphic adenomas/cutaneous mixed tumor can favor a diagnosis of benign salivary gland tumors, particularly in small biopsy specimens.

Association of Vascular Endothelial Growth Factor (VEGF) in Salivary Gland Tumors

Aim: To identify the association of vascular endothelial growth factor (VEGF) immunoexpression in the progression of salivary gland tumor. Study design: Comparative cross-sectional study Place and duration of study: Department of Pathology, Peshawar Medical College. Duration of study was six months from date of approval. Methodology: Forty five specimen of salivary gland tumor were studied in which 30 were benign and 15 were malignant. The endpoint assessment included Hematoxylin &amp; Eosin (H&amp;E) and VEGF immunoexpression. Results: The association of VEGF expression with salivary gland tumor was statistical significant (P&lt;0.05). Maximum 18 samples (benign: 13, malignant: 5) were shown to have strong expression, 24 (benign: 16, malignant: 8) were shown moderate expression. Whereas, small and no expression was found in 2 (benign: 0, malignant: 2) and 1 (benign: 1, malignant: 0) sample, respectively. Conclusion: Overexpression of VEGF in both malignant and benign salivary gland tumors might be associated to progress salivary gland tumors. Keywords Benign tumor, Warthin tumor, Adenoma, Salivary gland carcinoma, Vascular endothelial growth factor

Diagnostic efficacy of diffusion-weighted imaging and semiquantitative and quantitative dynamic contrast-enhanced magnetic resonance imaging in salivary gland tumors.

Increased use of functional magnetic resonance imaging (MRI) methods such as diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI consisting of sequential contrast series, allows us to obtain more information on the microstructure, cellularity, interstitial distance, and vascularity of tumors, which has increased the discrimination power for benign and malignant salivary gland tumors (SGTs). In the last few years, quantitative DCE MRI data containing T1 perfusion parameters (Ktrans, Kep and Ve), were reported to contribute to the differentiation of benign or malignant subtypes in SGTs. To evaluate the diagnostic efficacy of DWI and semiquantitative and quantitative perfusion MRI parameters in SGTs. Diffusion MRI [apparent diffusion coefficient (ADC) value] with a 1.5 T MR machine, semiquantitative perfusion MRI [time intensity curve (TIC) pattern], and quantitative perfusion MRI examinations (Ktrans, Kep and Ve) of 73 tumors in 67 patients with histopathological diagnosis performed from 2017 to 2021 were retrospectively evaluated. In the ADC value and semiquantitative perfusion MRI measurements, cystic components of the tumors were not considered, and the region of interest (ROI) was manually placed through the widest axial section of the tumor. TIC patterns were divided into four groups: Type A = Tpeak > 120 s; type B = Tpeak ≤ 120 s, washout ratio (WR) ≥ 30%; type C = Tpeak ≤ 120 s, WR < 30%; and type D = flat TIC. For the quantitative perfusion MRI analysis, a 3D ROI was placed in the largest solid component of the tumor, and the Ktrans, Kep and Ve values were automatically generated. The majority of SGTs were located in the parotid glands (86.3%). Of all the SGTs, 68.5% were benign and 31.5% were malignant. Significant differences were found for ADC values among pleomorphic adenomas (PMAs), Warthin's tumors (WTs), and malignant tumors (MTs) (P < 0.001). PMAs had type A and WTs had type B TIC pattern while the vast majority of MTs and other benign tumors (OBTs) (54.5% and 45.5%, respectively) displayed type C TIC pattern. PMAs showed no washout, while the highest mean WR was observed in WTs (59% ± 11%). Ktrans values of PMAs, WTs, OBTs, and MTs were not significantly different. Kep values of PMAs and WTs were significantly different from those of OBTs and MTs. Mean Ve value of WTs was significantly different from those of PMAs, OBTs, and MTs (P < 0.001). The use of quantitative DCE parameters along with diffusion MRI and semiquantitative contrast-enhanced MRI in SGTs could improve the diagnostic accuracy.

The Impact of Tissue Preparation on Salivary Gland Tumors Investigated by Fourier-Transform Infrared Microspectroscopy.

Due to the wide variety of benign and malignant salivary gland tumors, classification and malignant behavior determination based on histomorphological criteria can be difficult and sometimes impossible. Spectroscopical procedures can acquire molecular biological information without destroying the tissue within the measurement processes. Since several tissue preparation procedures exist, our study investigated the impact of these preparations on the chemical composition of healthy and tumorous salivary gland tissue by Fourier-transform infrared (FTIR) microspectroscopy. Sequential tissue cross-sections were prepared from native, formalin-fixed and formalin-fixed paraffin-embedded (FFPE) tissue and analyzed. The FFPE cross-sections were dewaxed and remeasured. By using principal component analysis (PCA) combined with a discriminant analysis (DA), robust models for the distinction of sample preparations were built individually for each parotid tissue type. As a result, the PCA-DA model evaluation showed a high similarity between native and formalin-fixed tissues based on their chemical composition. Thus, formalin-fixed tissues are highly representative of the native samples and facilitate a transfer from scientific laboratory analysis into the clinical routine due to their robust nature. Furthermore, the dewaxing of the cross-sections entails the loss of molecular information. Our study successfully demonstrated how FTIR microspectroscopy can be used as a powerful tool within existing clinical workflows.

Palatal swelling: Pleomorphic adenoma – A case report

Pleomorphic adenoma is a most common benign neoplasm of salivary glands that has the epithelial as well as the mesenchymal elements. The World Health Organization in 1972 defined pleomorphic adenoma as a “well-defined tumor characterized by its pleomorphic or mixed appearance.” There is intermixing of the clearly identified epithelial components with mucoid, myxoid, and chondroid components. Pleomorphic adenoma most commonly arises in the parotid or submandibular gland and infrequently occurs in minor salivary glands and presents as intraoral swellings on the palate or lip. The tumor shows a malignant transformation rate of about 9%, and a high recurrence rate has been reported. This case report highlights the clinical, radiological, and histopathological presentation of pleomorphic adenoma.

TERT Promoter Mutation in Benign and Malignant Salivary Gland Tumors; A Cross-Sectional Study.

Telomere-related tumorigenesis mechanisms in the salivary gland, including mutation in the promoter region of TERT, have been rarely investigated. Therefore, the present study aimed to investigate the mutation in the promoter region of TERT in benign and malignant salivary gland tumors. This was a descriptive-analytical cross-sectional study. Tissue samples of 54 patients with primary salivary gland tumors sent to the pathology department of Rasool-e-Akram Hospital from September 2017 to September 2021 were examined. Fifteen samples including two groups of the most common benign tumors (n=5; 3 pleomorphic adenomas and 2 Warthin tumors) and four groups of the most common malignant tumors (n=10; 3 mucoepidermoid carcinomas, 3 adenoid cystic carcinomas, 2 acinic cell carcinoma, and 2 salivary duct carcinoma) were selected. The promoter region of TERT, including well-known hot spot regions, is sequenced using the Sanger sequencing method. Data were analyzed using statistical software R version 4.1.2. Of 15 salivary gland tumor specimens, consisting of 5 benign tumors and 10 malignant tumors after DNA sequencing, TERT promoter region mutation was only seen in one of the adenoid cystic carcinoma samples, located at -146 bp upstream from ATG (chr5: 1,295,250 C>T). TERT promoter mutation was not different in malignant and benign salivary tumors. Nonetheless, there are a few studies that report TERT promoter mutation in adenoid cystic carcinoma of the salivary gland, necessitating the need for further investigations.

BASAL CELL ADENOMA OF PAROTID GLAND: A RARE CASE REPORT AND REVIEW OF LITERATURE

Salivary gland tumors are uncommon and constitute about 2.0 to 6.5 % of all head and neck tumors. Basal cell adenoma (BCA), which is classied in benign salivary gland tumors by WHO in 1991, is a rare neoplasm. Incidence rate of BCA is 1.0 %–3.7 % of all salivary gland tumors with most frequent location is the parotid gland(&gt;80% cases of BCA) and other sites such as the upper lip, buccal mucosa, lower lip, palate and nasal septum rarely affected. It usually presents as a rm and mobile slow-growing mass. Histologically, it consists of a monomorphic population of basaloid epithelial cells that are arranged in the solid, trabecular, tubular and membranous patterns. It is important to differentiate BCA from benign tumor like pleomorphic adenoma showing absence of chondromyxoid stroma in former and malignant tumor like basal cell adenocarcinoma, adenoid cystic carcinoma and basaloid squamous cell carcinoma. We report a case of BCA of the parotid gland in 59 year male. We also review the literature and discuss the diagnosis and management of this rare entity.