Analysis of the Clinical Relevance of Histological Classification of Benign Epithelial Salivary Gland Tumours

MiR-26a and miR-191 are upregulated while PLAG1 and HIF2 are downregulated in pleomorphic adenomas of the salivary glands compared to Warthin tumors

BACKGROUND

Salivary gland tumors (SGTs) are a heterogenous group of pathologies, which still represents a challenge regarding differential diagnosis and therapy. Although histological findings govern SGTs management, detection of molecular alterations is emerging as an effective additional tool. The aim of this study was to analyze the relative expression levels of three micro RNAs (miR-26a, miR-26b, and miR-191), and three pro-oncogenic molecular markers (PLAG1, MTDH, and HIF2) in SGTs and normal salivary gland (NSG) tissues and evaluate them as potential differential diagnosis markers.

METHODS

This cross-sectional study included 58 patients with SGTs (23 pleomorphic adenomas, 27 Warthin tumors, and 8 malignant SGTs) and 10 controls (normal salivary gland tissues). Relative gene expression levels of all investigated molecules were determined by reverse transcriptase-real-time polymerase chain reaction.

RESULTS

All three micro RNAs exhibited highest expression levels in benign SGTs, whereas miR-26a And miR-191 were significantly more expressed in PAs compared to WTs (p = 0.045 and p = 0.029, respectively). PLAG1 And HIF2 were both overexpressed in WTs compared to PAs (p = 0.048 and p = 0.053, respectively). Bioinformatic analysis suggested that all investigated micro RNAs function as negative regulators of MTDH.

CONCLUSION

The results of this study suggest that all three micro RNAs have a considerable negative impact on MTDH oncogene expression in malignant tumors, while the differences between levels of miR-26a, miR-191, PLAG1, and HIF2 in PA and WT represent possible differential diagnosis markers.

The value of diffusion kurtosis imaging and dynamic contrast-enhanced magnetic resonance imaging in the differential diagnosis of parotid gland tumors

Background

Parotid gland tumors (PGTs) are the most common benign tumors of salivary gland tumors. However, the diagnostic value of relative values of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion kurtosis imaging (DKI) parameters for PGTs has not been extensively studied. Therefore, this study aimed to evaluate the diagnostic performance of combined DKI and DCE-MRI for differentiating PGTs by introducing the concept of relative value.

Methods

The DCE-MRI and DKI imaging data of 142 patients with PGTs between June 2018 and August 2022 were collected. Patients were divided into four groups by histopathology: malignant tumors (MTs), pleomorphic adenomas (PAs), Warthin tumors (WTs), and basal cell adenomas (BCAs). All MRI examinations were conducted using a 3 T MRI scanner with a 20-channel head and neck coil. Quantitative parameters of DCE-MRI and DKI and their relative values were determined. Kruskal-Wallis H test, post-hoc test with Bonferroni correction, one-way analysis of variance (ANOVA) and post-hoc test with least significant difference (LSD) method, and the receiver operating characteristic (ROC) curve were used for statistical analysis. Statistical significance was set at P<0.05.

Results

Only the combination of DKI and DCE-MRI parameters could reliably distinguish BCAs from other PGTs. PAs demonstrated the lowest transfer constant from plasma to extravascular extracellular space (Ktrans) value [0.09 (0.06, 0.20) min-1], relative Ktrans (rKtrans) [-0.24 (-0.64, 1.00)], rate constant from extravascular extracellular space to plasma (Kep) value [0.32 (0.22, 0.53) min-1], relative Kep (rKep) [0.32 (0.22, 0.53) min-1], and initial area under curve (iAUC) value [0.15 (0.09, 0.26) mmol·s/kg] compared with WTs, BCAs, and MTs (all P<0.05). The Ktrans values for MTs were substantially lower [0.17 (0.10, 0.31) min-1] than those for WTs (P=0.01). The Kep values for MTs [0.71 (0.52, 1.28) min-1] were substantially lower (all P<0.05) than those for WTs and BCAs. PAs and BCAs had higher diffusion coefficient (D) values and lower diffusion kurtosis (K) values and relative K (rK) values than MTs and WTs. However, the D and K values did not differ significantly even in their relative values of PAs and BCAs (all P>0.05). By using logistic regression, the combination of K value and rKep value further enhanced their discriminatory power between PAs and WTs [area under the ROC curve (AUC), 0.986], the combination of K and rKep value further enhanced their discriminatory power between PAs and MTs (AUC, 0.915), and the combination of D and Kep value further enhanced their discriminatory power between BCAs and MTs (AUC, 0.909).

Conclusions

DKI and DCE-MRI can be used to differentiate PGTs quantitatively and can complement each other. The combined use of DKI and DCE-MRI parameters can improve the diagnostic accuracy of distinguishing PGTs.

Intraoral Salivary Gland Cystadenomas: A Case Series Study and Literature Review

BACKGROUND

Salivary gland cystadenoma (SGCA) is a rare benign tumor that predominantly occurs in the parotid gland. SGCAs affecting the minor salivary glands are uncommon and often resemble, clinically and histopathologically, other salivary gland lesions.

METHODS

This study aimed to describe a series of four cases of SGCA affecting intraoral sites and performed a literature review of well-reported SGCA published in the English-language literature.

RESULTS

SGCA cases included in this series were diagnosed in the buccal mucosa, lip, and hard palate of female patients aged between 19 and 78 years. All cases underwent excisional biopsy and were histologically characterized by a multicystic growth with variable degrees of capsule formation and were lined by several types of epithelium, including some cell types that are infrequently reported in SGCA. In some cases, a small collection of lymphocytes was observed adjacent to cystic formations. All SGCA were positive for periodic acid-Schiff, and immunohistochemical reactions were positive for CK7 and p63. The follow-up time ranged widely from 3 to 53 months, and to date, no recurrence has been observed.

CONCLUSION

The literature review revealed a total of 33 published studies accounting for 55 SGCA cases.

Utility of fine-needle aspiration biopsy (FNAB) in parotid pleomorphic adenoma diagnosis and management

PURPOSE

Pleomorphic adenoma (PA), the most common benign tumour of the parotid gland, requires accurate preoperative diagnosis owing to its capacity for malignant transformation. The aim of this study was to evaluate our experience with ultrasound-guided fine-needle aspiration biopsy (FNAB) in the diagnostic algorithm for patients with PA and to assess clinical outcomes for those with different surgical approaches.

MATERIAL AND METHODS

We carried out a retrospective analysis of patients treated for parotid gland mass between 2010 and 2016. These had had preoperative FNAB and had undergone subsequent surgery.

RESULTS

165 patients had FNAB with the result of PA and the definitive histology confirmed PA in 159 cases (96.4%). On the other hand, in 179 patients, the definitive histology showed PA and the preoperative FNAB result corresponded in 159 cases (88.9%). The measured sensitivity, specificity and accuracy of ultrasound-guided FNAB in the diagnosis of PA were, respectively, 88.83%, 96.23% and 92.31%. Most of the patients underwent superficial or partial superficial parotidectomy, followed by extracapsular dissection which was associated with statistically lower risk of facial nerve injury (P=0.04).

CONCLUSION

Ultrasound-guided FNAB is simple, accurate and valuable in the diagnosis of PA and provides results that can lead to the choice of less invasive operative treatment.

Evaluation of Quantitative Dual-Energy Computed Tomography Parameters for Differentiation of Parotid Gland Tumors

RATIONALE AND OBJECTIVES

To assess the diagnostic performance of quantitative parameters from dual-energy CT (DECT) in differentiating parotid gland tumors (PGTs).

MATERIALS AND METHODS

101 patients with 108 pathologically proved PGTs were enrolled and classified into four groups: pleomorphic adenomas (PAs), warthin tumors (WTs), other benign tumors (OBTs), and malignant tumors (MTs). Conventional CT attenuation and DECT quantitative parameters, including iodine concentration (IC), normalized iodine concentration (NIC), effective atomic number (Zeff), electron density (Rho), double energy index (DEI), and the slope of the spectral Hounsfield unit curve (λHU), were obtained and compared between benign tumors (BTs) and MTs, and further compared among the four subgroups. Logistic regression analysis was used to assess the independent parameters and the receiver operating characteristic (ROC) curves were used to analyze the diagnostic performance.

RESULTS

Attenuation, Zeff, DEI, IC, NIC, and λHU in the arterial phase (AP) and venous phase (VP) were higher in MTs than in BTs (p < 0.001-0.047). λHU in VP and Zeff in AP were independent predictors with an area under the curve (AUC) of 0.84 after the combination. Furthermore, attenuation, Zeff, DEI, IC, NIC, and λHU in the AP and VP of MTs were higher than those of PAs (p < 0.001-0.047). Zeff and NIC in AP and λHU in VP were independent predictors with an AUC of 0.93 after the combination. Attenuation and Rho in the precontrast phase; attenuation, Rho, Zeff, DEI, IC, NIC, and λHU in AP; and the Rho in the VP of PAs were lower than those of WTs (p < 0.001-0.03). Rho in the precontrast phase and attenuation in AP were independent predictors with an AUC of 0.89 after the combination. MTs demonstrated higher Zeff, DEI, IC, NIC, and λHU in VP and lower Rho in the precontrast phase compared with WTs (p < 0.001-0.04); but no independent predictors were found.

CONCLUSION

DECT quantitative parameters can help to differentiate PGTs.

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.

Myoepithelioma of the Palatal Minor Salivary Gland: A Case Report

Myoepithelioma is an uncommon benign tumor of the orofacial region arising from the salivary glands. These tumors are composed of specifically myoepithelial cells lacking ductal differentiation and were initially considered as a type of pleomorphic adenoma. Though they commonly arise from the parotid gland, there are a few cases that emerge from the minor salivary glands of the palate and oral cavity. Myoepitheliomas resemble many other tumors arising from the palate including pleomorphic adenoma. This report depicts a case of myoepithelioma of the minor salivary gland of the palate in a 23-year-old patient and the successful management of the lesion.

Extraoral type of intraductal papilloma in sublingual gland

INTRODUCTION

It is rare for intraductal papilloma (IDP), a benign papillary tumor, to occur in the sublingual gland (SLG).

CASE SUMMARY

A 55-year-old man incidentally found a painless mass in his left submandibular region (SMR). He had a history of two surgeries for bilateral SLG cyst. Contrast enhanced ultrasound (CEUS) and magnetic resonance imaging (MRI) were performed. The patient received trans-cervical excision of left residual SLG in combination with excision of left submandibular gland (SMG). The postoperative course was uneventful and no signs of recurrence during 5 months of follow-up.

DISCUSSION

For a SMR mass, extraoral type of IDP in SLG should be considered in the differential diagnosis.

Ultrasound-guided percutaneous thermal ablation of parotid tumors: experience from two-centers

Objective: To evaluate the efficacy and feasibility of ultrasound-guided percutaneous thermal ablation (TA) for treating benign parotid tumors.Methods: Patients with benign parotid tumors who underwent ultrasound-guided microwave ablation (MWA) or radiofrequency ablation (RFA) between January 2020 and March 2023 were included in this retrospective study. Change in tumor size (maximum diameter, tumor volume(V), volume reduction rate (VRR)) and cosmetic score (CS) were evaluated during a one-year follow-up period. We also recorded the incidence of any complications associated with TA.Results: A total of 23 patients (13 males and 10 females; median age 65 years, range 5-91 years) were included. The mean VRR at 1, 3, 6, and 12 months after TA was 37.03%±10.23%, 56.52%±8.76%, 82.28%±7.89%, and 89.39%±6.45%, respectively. Mean CS also changed from 3.39 ± 0.66 to 1.75 ± 0.93 (p < 0.001) by the end of follow-up time. Subgroup analysis showed that tumors with smaller initial maximum diameter had a faster CS reduction rate than those with larger initial diameter. The incidence of facial nerve dysfunction was 8.70%.Conclusion: Ultrasound-guided percutaneous TA is an effective and safe treatment option for patients with benign parotid tumors.

FGFR2 point mutation in 2 cases of pleomorphic adenoma progressing to myoepithelial carcinoma

Introduction

Salivary gland tumours are rare neoplasms. Pleomorphic adenoma (PA) is the most frequent benign lesion. Myoepithelial carcinoma (MECA) is rarely recognized malignancy, but the prognosis is unfavourable. The aim of this study was to identify genetic rearrangements that might be responsible for dynamic MECA progression in patients with primary radical PA excision.

Material and methods

Next-generation sequencing (NGS) of 1500 gene coding sequences was performed in primary and recurrent tumour tissue collected from 2 patients, in whom PA was initially diagnosed and within one year multifocal MECA was detected. Formalin-fixed paraffin-embedded blocks with tumour tissues were subject to NGS analysis, involving small-scale mutations, as well as focal and chromosomal arm-level copy number changes.

Results

This study showed mutations in the FGFR2 gene in PA and MECA tissues, obtained from both patients. One of them, pathogenic mutation p.Pro253Arg, was associated with sensitivity to registered drug inhibitors. Additionally, FGFR1, EGFR, and CDK4/CDK6 amplification, as well as CDKN2A/B deletion, were detected in one case. Furthermore, mutations in suppressor gene APC2 and PIK3C2A were detected, but only in MECA tissue. The analysis also identified the following chromosomal copy alterations: 4q12-q13.3, 9p21.3, 5q23.1-q34, del8p23.3-p12, and del13q21.31-q31.1.

Conclusions

Rearrangement of the FGFR2 gene, identified in primary PA and MECA ex PA samples of both our patients, may be responsible for the malignant transformation and the disease progression. Further studies are encouraged to confirm the relevance of the findings. The therapy option with FGFR2 inhibitors may be considered in advanced or metastatic MECA ex PA with confirmed FGFR2 mutations.

Influence of p16 Protein Immunostaining on Histopathological Features of Pleomorphic Adenoma and Carcinoma ex- Pleomorphic Adenoma

The objective of this study was to evaluate the role of p16 in histologic characteristics and transition of Pleomorphic Adenoma (PA) to Carcinoma ex-PA (CxPA). So, 60 PA and 4 CxPA were histologic reviewed based on microscopic characteristics proposed by Hellquist, Triantafyllou and Dulguerov (PA) and Morais, Antony and Toluie (CxPA). Immunostaining for p16 was associated in different parenchyma and stroma of both tumors and Fisher's/chi-square tests and Mann-Whitney test were performed (SPSS v20.0, p<0.05). In PA the periductal cells were predominantly p16- and that ductal and myoepithelial cells showed a significant increase in p16+ cells (p<0.001). In CxPA, none of the cases showed p16+ in periductal cells, most parotid cases showed p16+ in ductal cells, and one case of parotid and the submandibular case showed mild immunostaining for myoepithelial cells. There was a small reduction in p16+ in CxPA compared to PA (p=0.537), but in both tumors there was less p16+ cells in solid stroma than other (p<0.001). The p16+ cases of PA had a higher capsular thickness (p=0.047). So, the loss of p16 immunostaining does not seem to be associated with the transition from PA to CxPA, but in both tumors the loss of p16+ cells are related to microscopic aggressiveness.

Ultrasonography characteristics of cystic components in primary salivary gland tumors

OBJECTIVES

The present study aimed to characterize the ultrasonography (US) features of cystic components in salivary gland tumors (SGTs).

MATERIALS AND METHODS

A total of 207 patients (218 lesions) with pathologically confirmed primary SGTs were analyzed. Preoperative US revealed the presence of cystic components in lesions. Lesion size, shape, margin, and US findings of the cystic components, including number, distribution, margin, occupying rate, and internal characteristics, were evaluated.

RESULTS

Similarities were observed between the US performance of benign SGTs (B-SGTs) and malignant SGTs (M-SGTs) with cystic components. Differences in sex and age of patients, number, distribution, and internal characteristics of cystic components were statistically significant. For SGTs with cystic components, the proportions of M-SGTs to ill-defined margins (P = 0.002), eccentric distribution (P = 0.019), and none of the internal characteristics (P = 0.019) were significantly higher than those of B-SGTs. Younger age (P = 0.001), eccentric distribution (P = 0.034) and ill-defined margin (P < 0.001) were risk factors for diagnosing M-SGTs. Cystic component features needed to be combined with lesion indicators (border and shape) to improve diagnostic sensitivity.

CONCLUSIONS

US features of the B-SGTs and M-SGTs were significantly different. Cystic component is of interest in the US-related differential diagnosis of B-SGT and M-SGT.

CLINICAL RELEVANCE

Cystic components are potentially valuable in the differential diagnosis of B-SGTs and M-SGTs on US.

Basal cell adenoma of parotid gland: two case reports and literature review

Most of salivary tumors are benign in nature and are typically diagnosed and classified based on their histopathological presentation. Basal cell adenoma of the salivary glands is a rare, benign disease accounting for 1% to 3% of salivary gland tumors. Despite its low incidence, basal cell adenoma is the third most common benign tumor of the salivary gland after pleomorphic adenoma and Warthin's tumor. It usually appears as a firm and slow-growing mass. Due to the prognosis, differential diagnosis with basal cell adenocarcinoma, adenoid cystic carcinoma and basaloid squamous cell carcinoma is required. In this report, we present two cases; a 62-year-old woman who presented with an asymptomatic, and slow-growing mass and a 64-year-old woman with a static-sized mass in the parotid gland. In both cases, the mass was completely excised, postoperative pathology reports confirmed the diagnosis of basal cell adenoma. We also review the literature and discuss this rare entity.

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

OBJECTIVES

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.

STUDY DESIGN

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.

RESULTS

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.

CONCLUSIONS

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.

Pleomorphic adenoma in tonsil

Salivary tumors that involve the tonsil are rare, representing 0.5% of salivary neoplasms. Most tumors arise from the parotid glands. Rare studies have been reported in the literature regarding pleomorphic adenomas affecting the tonsil. Patients are usually asymptomatic and present with a slow-growing, mobile and painless mass. Radiological examinations are usually unable to differentiate benign from malignant tumors in most cases. There is low recurrence with complete excision of the tumor. The prognosis is excellent except in the rare cases of malignant transformation. This report describes the management of a case of pleomorphic adenoma affecting the palatine tonsils and the difficulty regarding the histopathological diagnosis.

Basal Cell Adenoma With Atypia in the Nasal Cavity Mimicking a Malignant Tumor

Basal cell adenomas (BCA) arising from the nasal cavity or paranasal sinuses are very rare. A 64-year-old male patient was suspected of having a malignant tumor after undergoing preoperative computed tomography scans and magnetic resonance imaging. The intraoperative frozen section showed a malignant tumor; however, the final diagnosis revealed BCA with atypia, tubular pattern.

Simultaneous Expression of PD-1 and PD-L1 in Peripheral and Central Immune Cells and Tumor Cells in the Benign and Malignant Salivary Gland Tumors Microenvironment

BACKGROUND

To investigate the differential expression of PD-1 and PD-L1 in salivary gland tumors (SGTs, malignant and benign subtypes) and determine their association with the clinicopathological characterization of the patients.

METHODS

The immunohistochemistry was used to examine PD-1 and PD-L1 expression in specimens from 83 patients with primary SGTs including salivary ductal carcinoma (SDC), adenoid cystic carcinoma (AdCC), acinic cell carcinoma (ACC), mucoepidermoid carcinoma (MEC), warthin's tumors (WT), poleomorphic adenoma (PA) and other subtypes.

RESULTS

The expression of PD-1 in peripheral and central immune cells (ICs) of MEC, and peripheral ICs of ACC was significantly higher than those with AdCC (P = 0.02, P = 0.02, P = 0.03, respectively). Interestingly, the expression of PD-1 was also observed in peripheral and central malignant tumor cells (TCs), particularly in SDC and ACC. Despite no significant difference in PD-L1 expression of TCs among malignant subtypes, the peripheral and central ICs of ACC and MEC were revealed to express PDL-1 significantly more than those with AdCC (P < 0.05). WTs were rich in PD-1/PD-L1 expressing ICs. However, the tumor microenvironment of PA generally had low levels of PD-1/PD-L1 expression. In general, the expression of PD-1 in peripheral and central TCs was found to be significantly higher in malignant tumors than in benign ones (P = 0.002 and P = 0.003, respectively).

CONCLUSION

The simultaneous presentation of PD-1 and PD-L1 in TCs and ICs of SGTs, their significant association with disease severity as well as the positive correlation between these immune checkpoints may suggest the therapeutic potential of anti-PD-1 and anti-PDL-1 combinational immunotherapy for SGTs.

Enhanced CT-based texture analysis and radiomics score for differentiation of pleomorphic adenoma, basal cell adenoma, and Warthin tumor of the parotid gland

OBJECTIVE

To evaluate the diagnostic performance of computed tomography (CT) radiomics analysis for differentiating pleomorphic adenoma (PA), Warthin tumor (WT), and basal cell adenoma (BCA).

METHODS

A total of 189 patients with PA (n = 112), WT (n = 53) and BCA (n = 24) were divided into a training set (n = 133) and a test set (n = 56). The radiomics features were extracted from plain CT and contrast-enhanced CT images. After dimensionality reduction, plain CT, multiphase-enhanced CT, integrated radiomics signature models and radiomics score (Rad-score) were established and calculated. The receiver operating characteristic (ROC) curve analysis was taken for the assessment of the model performance, and then comparison was conducted among these models. Decision curve analysis (DCA) was adopted to assess the clinical benefits of the models. Diagnostic performances including sensitivity, specificity, and accuracy of the radiologists were evaluated.

RESULTS

Seven, nine, fourteen, and fourteen optimal features were used to constructed plain scan, arterial phase, venous phase, and integrated radiomics signature models, respectively. ROC analysis showed these four models were able to differentiate PA from BCA and WT, with the area under the ROC curve (AUC) values of 0.79, 0.90, 0.87, and 0.94 in the training set, and 0.79, 0.89, 0.86, and 0.94 in the test set, respectively. The integrated model had better diagnostic performance than single-phase radiomics model, but it had similar diagnostic performance to that of the radiomics model based on the arterial phase (p > 0.05). The sensitivity, specificity, and accuracy in the diagnosis of PA were 0.86, 0.46, and 0.70 for the non-subspecialized radiologist and 0.88, 0.77, and 0.84 for the subspecialized radiologist, respectively. Six venous phase parameters were finally selected in differentiating WT from BCA. The predictive effect of the model was favorable, with AUC value of 0.95, sensitivity of 0.96, specificity of 0.83, and accuracy of 0.92. The sensitivity, specificity, and accuracy in the diagnosis between WT and BCA were 0.26, 0.87, and 0.45 for the non-subspecialized radiologist and 0.85, 0.58, and 0.77 for the subspecialized radiologist, respectively.

CONCLUSION

The CT-based radiomics analysis showed favorable predictive performance for differentiating PA, WT, and BCA, thus may be helpful in the clinical decision-making.

The Diagnostic Value of Fine Needle Aspiration Biopsy in Parotid Tumors

The aim of this study was to investigate the diagnostic accuracy rates of the patients who underwent an operation for parotid mass, by comparing their fine needle aspiration biopsy (FNAB) cytology results with the final pathology. A total of 136 patient files of those who applied to Otorhinolaryngology clinic due to parotid mass and underwent parotidectomy procedure between 2010 and 2020 at a tertiary center were scanned retrospectively. Database on patient age, gender, preoperative FNAB results, and final surgical histopathology results was created. The mean age of the patients was 48.26 ± 17.37 Superficial parotidectomy was performed to 108 (79.4%) and total parotidectomy to 28 (20.6%) of the patients. The sensitivity of FNAB was found as 85.2%, specificity as 96.2%, positive predictive value as 85.2%, negative predictive value as 96.2% and accuracy as 94.0%. It is found that FNAB has the high specificity and high negative predictive value with high diagnostic accuracy on detecting preoperative malignancy in parotid gland. We think that FNAB is a significant, necessary and safe method in the diagnosis of parotid lesions in preoperative sense.

Diagnostic role of DOG-1, GFAP and B-catenin in Basal cell Adenoma and Cellular Pleomorphic Adenoma of the Salivary Gland

BACKGROUND

Pleomorphic Adenoma (PA) and Basal cell adenoma (BCA) are benign salivary gland tumors that may pose a diagnostic challenge if typical features are not present. Due to the increased relapse and malignant transformation rate of the former, a correct diagnosis carries relevant prognostic information. Even though immunohistochemistry (IHC) plays a limited role in the diagnosis of these tumors, the use of IHC panels could increase diagnostic accuracy. In the present work, we aimed to demonstrate that the use of an IHC panel consisting of Glial Fibrillary Acid Protein (GFAP), B-Catenin and Discovered On GIST 1 (DOG-1) can aid in the differential diagnosis between PA and BCA.

METHODS

We analyzed 18 cases of benign salivary gland tumors (Pleomorphic adenomas and Basal cell adenomas) with overlapping histologic features. First, a head and neck pathologist diagnosed the cases relying on morphology alone. Afterwards, cases were re-evaluated considering the IHC panel results. Inter-observer IHC scoring concordance was evaluated with pre-defined marker cut-off points using Cohen's Kappa scores.

RESULTS

Based on morphology alone, 9 cases were classified as PA while the remaining tumors were considered to be BCA. Five out of nine BCA cases showed GFAP staining and absent nuclear B-catenin and DOG-1 positivity. Conversely, 2 PA cases showed absent GFAP and positive nuclear B-catenin with concurrent DOG-1 expression. Therefore, after IHC evaluation, up to 40% of morphologic diagnoses were reconsidered. Overall, the inter-observer concordance for IHC evaluation was good (resulting Kappa Scores between 0.78 and 1).

CONCLUSION

Our work supports the use of a concise IHC panel to improve the diagnostic accuracy of benign salivary gland tumors with overlapping histologic features.

Comparison of Different Machine Models Based on Multi-Phase Computed Tomography Radiomic Analysis to Differentiate Parotid Basal Cell Adenoma From Pleomorphic Adenoma

Objective

This study explored the value of different radiomic models based on multiphase computed tomography in differentiating parotid pleomorphic adenoma (PA) and basal cell tumor (BCA) concerning the predominant phase and the optimal radiomic model.

Methods

This study enrolled 173 patients with pathologically confirmed parotid tumors (training cohort: n=121; testing cohort: n=52). Radiomic features were extracted from the nonenhanced, arterial, venous, and delayed phases CT images. After dimensionality reduction and screening, logistic regression (LR), K-nearest neighbor (KNN) and support vector machine (SVM) were applied to develop radiomic models. The optimal radiomic model was selected by using ROC curve analysis. Univariate and multivariable logistic regression was performed to analyze clinical-radiological characteristics and to identify variables for developing a clinical model. A combined model was constructed by integrating clinical and radiomic features. Model performances were assessed by ROC curve analysis.

Results

A total of 1036 radiomic features were extracted from each phase of CT images. Sixteen radiomic features were considered valuable by dimensionality reduction and screening. Among radiomic models, the SVM model of the arterial and delayed phases showed superior predictive efficiency and robustness (AUC, training cohort: 0.822, 0.838; testing cohort: 0.752, 0.751). The discriminatory capability of the combined model was the best (AUC, training cohort: 0.885; testing cohort: 0.834).

Conclusions

The diagnostic performance of the arterial and delayed phases contributed more than other phases. However, the combined model demonstrated excellent ability to distinguish BCA from PA, which may provide a non-invasive and efficient method for clinical decision-making.

Differentiation of Benign From Malignant Parotid Gland Tumors Using Conventional MRI Based on Radiomics Nomogram

Objectives

We aimed to develop and validate radiomic nomograms to allow preoperative differentiation between benign- and malignant parotid gland tumors (BPGT and MPGT, respectively), as well as between pleomorphic adenomas (PAs) and Warthin tumors (WTs).

Materials and Methods

This retrospective study enrolled 183 parotid gland tumors (68 PAs, 62 WTs, and 53 MPGTs) and divided them into training (n = 128) and testing (n = 55) cohorts. In total, 2553 radiomics features were extracted from fat-saturated T2-weighted images, apparent diffusion coefficient maps, and contrast-enhanced T1-weighted images to construct single-, double-, and multi-sequence combined radiomics models, respectively. The radiomics score (Rad-score) was calculated using the best radiomics model and clinical features to develop the radiomics nomogram. The receiver operating characteristic curve and area under the curve (AUC) were used to assess these models, and their performances were compared using DeLong’s test. Calibration curves and decision curve analysis were used to assess the clinical usefulness of these models.

Results

The multi-sequence combined radiomics model exhibited better differentiation performance (BPGT vs. MPGT, AUC=0.863; PA vs. MPGT, AUC=0.929; WT vs. MPGT, AUC=0.825; PA vs. WT, AUC=0.927) than the single- and double sequence radiomics models. The nomogram based on the multi-sequence combined radiomics model and clinical features attained an improved classification performance (BPGT vs. MPGT, AUC=0.907; PA vs. MPGT, AUC=0.961; WT vs. MPGT, AUC=0.879; PA vs. WT, AUC=0.967).

Conclusions

Radiomics nomogram yielded excellent diagnostic performance in differentiating BPGT from MPGT, PA from MPGT, and PA from WT.

Oncocytic variant of sialadenoma papilliferum - a rare salivary gland tumor: A case report

Background

Sialadenoma papilliferum (SP) is a rare minor salivary gland neoplasm that accounts for less than 1% of all salivary gland tumors. The tumor typically affects older people, presenting most commonly as a slow-growing tumor of the hard palate, although other anatomical subsites, comprising the oral cavity and parotid glands, have also been reported.

Case Report

We report a SP occurring in a 90-year-old female. The patient described feeling a nodule on her palate for several years. The lesion was painless and clinically resembled a round craterlike ulceration of diameter 3 mm. The excisional biopsy was diagnosed histologically as SP. Here, we report the clinicopathological and radiological findings of palatal SP.

Conclusions

SP is a rare, benign salivary gland neoplasm, and there are only a few cases described in the literature. Although mostly benign, malignant transformation can occur and should prompt the clinician to ensure complete removal of the tumor tissue.

Key words:Sialadenoma papilliferum, minor salivary gland tumor, histopathology, oral pathology, case report.

Intraductal papilloma of the sublingual gland imitating a ranula

Ductal papillomas are rare benign lesions of the salivary glands with two distinctive types, intraductal and inverted. The rarest anatomical location where intraductal papillomas occur is the major salivary glands. In the present study, we report an intraductal papilloma of the left sublingual gland with the relevant clinical, imaging, and histopathological findings and postoperative follow-up. To our knowledge, this is the fourth case of an intraductal papilloma of a sublingual gland to be reported in the international literature. We present this rare case because of its clinical and radiological imitation of a ranula.

[Complications in the surgery of the parotid salivary glands. Causes, mechanisms of development, methods of prevention]

Operations for neoplasms of the parotid salivary gland require from the surgeon a deep knowledge of the anatomical and topographic features of this area and technical skill, which puts it in a number of «jewelry» operations that require patience and concentration. The review is devoted to the topic of specific postoperative complications after parotidectomy or subtotal resection of the gland. These include relapses of tumors, paralysis or paresis of facial muscles, Frey syndrome, salivary fistulas or sialocele, violation of skin sensitivity, soft tissue deformity. The review presents the frequency and causes of complications, mechanisms of their development, methods of prevention and elimination.

Practical immunohistochemistry in the classification of salivary gland neoplasms

Diagnosis of salivary gland neoplasms can be challenging for surgical pathologists due to low incidence of tumors as well as overlapping histologic features. On small biopsy, the most important information to be conveyed for clinical management is the distinction between a benign/low grade tumor and a high grade carcinoma. This review will discuss the differential diagnosis of salivary gland tumors based on four broad morphologic patterns: basaloid/tubular/cribriform, (micro)cystic/secretory/mucinous, solid-nested/clear-spindled, and oncocytic/oncocytoid. With the assistance of immunohistochemistry, demonstration of the number of cell types (mainly epithelial versus myoepithelial/basal) can further subclassify tumors within these morphologic categories. Additional tumor-specific immunomarkers are useful in some cases. Underlying tumor-specific genetic anomalies can be of value, however, immunohistochemical correlates are only available for some. When used judiciously, in the correct morphologic context, and with knowledge of their limitations, immunohistochemical stains can aid in differentiating tumors with similar morphology.

Diffusion kurtosis imaging and dynamic contrast-enhanced MRI for the differentiation of parotid gland tumors

OBJECTIVE

To assess the usefulness of combined diffusion kurtosis imaging (DKI) and dynamic contrast-enhanced MRI (DCE-MRI) in the differentiation of parotid gland tumors.

METHODS

Seventy patients with 80 parotid gland tumors who underwent DKI and DCE-MRI were retrospectively enrolled and divided into four groups: pleomorphic adenomas (PAs), Warthin tumors (WTs), other benign tumors (OBTs), and malignant tumors (MTs). DCE-MRI and DKI quantitative parameters were measured. The Kruskal-Wallis H test and post hoc test with Bonferroni correction and ROC curve were used for statistical analysis.

RESULTS

WTs demonstrated the highest K_ep value (median 1.89, interquartile range [1.46-2.31] min^-1) but lowest V_e value (0.20, [0.15-0.25]) compared with PAs (K_ep, 0.34 [0.21-0.55] min^-1; V_e, 0.36 [0.24-0.43]), OBTs (K_ep, 1.22 [0.27-1.67] min^-1; V_e, 0.28 [0.25-0.41]), and MTs (K_ep, 0.71 [0.50-1.23] min^-1; V_e, 0.35 [0.26-0.45]) (all p < .05). MTs had the lower D value (1.10, [0.88-1.29] × 10^-3 mm²/s) compared with PAs (1.81, [1.60-2.20] × 10^-3 mm²/s) and OBTs (1.57, [1.32-1.89] × 10^-3 mm²/s) (both p < .05). PAs had the lower K^trans value (0.12, [0.07-0.18] min^-1) compared with OBTs (0.28, [0.11-0.50] min^-1) (p < .05). The cutoff values of combined K_ep and V_e, D, and K^trans to distinguish WTs, MTs, and PAs sequentially were 1.06 min^-1, 0.28, 1.46 × 10^-3 mm²/s, and 0.21 min^-1, respectively (accuracy, 89% [71/80], 91% [73/80], 78% [62/80], respectively).

CONCLUSION

The combined use of DKI and DCE-MRI may help differentiate parotid gland tumors.

KEY POINTS

• The combined use of DKI and DCE-MRI could facilitate the understanding of the pathophysiological characteristics of parotid gland tumors. • A stepwise diagnostic diagram based on the combined use of DCE-MRI parameters and the diffusion coefficient is helpful for accurate preoperative diagnosis in parotid gland tumors and may further facilitate the clinical management of patients.

Comparative Study of Qualitative and Quantitative Analyses of Contrast-Enhanced Ultrasound and the Diagnostic Value of B-Mode and Color Doppler for Common Benign Tumors in the Parotid Gland

Purpose

To preliminarily identify three common benign parotid gland tumors: pleomorphic adenomas (PA), Warthin tumors (WT), and basal cell adenomas (BCA) by qualitative and quantitative analyses using contrast-enhanced ultrasound (CEUS).

Methods

Preoperative images of parotid gland masses were analyzed, including 129 cases of ultrasonography (US) and color Doppler sonography (CDS) and 110 cases of qualitative and quantitative CEUS. The diagnosis was confirmed by postsurgical pathology outcomes.

Results

PA presented low and heterogeneous enhancement and echo-free area, whereas most WT and BCA presented with high and relatively homogeneous enhancement. Compared with WT and BCA groups, a “slow in” pattern was more common in the PA group and a “slow out” pattern was more frequently noted in the WT group than in the PA and BCA groups. The unique features of qualitative CEUS in the PA group enable distinguishing PA from the 2 other groups. The further distinction among the groups was made based on quantitative parameters of time-intensity curves (TICs), which revealed that the mean peak intensity (PI), mean transit time (MTT), the area under the curve (AUC), and time from peak to one half (HT) exhibited significant differences. ROC analysis was next applied to determine the optimal cutoff points to predict the diagnostic tendency among the groups. When the rising slope (RS) was >2.145, the possibility of BCA was greater than WT.

Conclusions

CEUS ultrasound is of significant value in the differential diagnosis of the 3 common benign parotid gland masses.

Experience with follow-up strategy in selected patients with Warthin tumour diagnosed by ultrasound-guided fine-needle aspiration biopsy (FNAB)

PURPOSE

Warthin tumour (WT) management options comprise surgery or follow-up. The purpose of this study was to asses our experience with the follow-up strategy in selected patients with an ultrasound-guided fine-needle aspiration biopsy (FNAB) showing WT.

METHODS

We performed a retrospective analysis of patients diagnosed with WT using FNAB between 1.1.2006 and 31.12.2019. Patients were divided into three groups according to the therapeutic approach-immediate surgery, follow-up or surgery and follow-up.

RESULTS

323 patients were diagnosed with WT and met the study's inclusion criteria (154 women, 47.7% and 169 men, 52.3%). 192 patients were operated right after the diagnosis, 109 patients were observed with their first detected tumour and 22 patients had parotid WT surgery and were in the wait-and-scan protocol with a contralateral tumour, recurrence or both. The growth rate (GR) of observed WT was highly variable (mean GR 1.0 mm/year (5%), median GR 0.8 mm (9%), range - 19.7 to +20.0 mm/year). From 131 patients in the follow-up group, 19 patients underwent surgery and definitive histology revealed 17 WTs and 2 adenocarcinomas. However, these 2 patients had changes in sonographic findings at their next control. The mean observation time was 44.7 months (range 12-138 months) in patients followed exclusively at our institution and 50.9 months (range 12-110 months) in patients observed in cooperation with an otorhinolaryngologist at the patients' place of residence.

CONCLUSION

Ultrasound-guided FNAB is an accurate and simple method in WT diagnosis and based on its result a follow-up strategy can be chosen for selected patients with WT.

Cytopathology and diagnostics of Warthin's tumour

Warthin's tumour (WT) is a benign epithelial salivary tumour, one type of salivary adenoma. Histologically, WT is structured of two components, epithelial tissue that often lines cystic formations and lymphoid tissue in the tumour stroma. FNA is a reliable diagnostic approach in the diagnosis of salivary gland lesions allowing a highly accurate categorization of benign tumour-like lesions, benign tumours and malignant tumours. In the proposed Milan reporting system of salivary gland lesions, WT is categorized in the IVA group of benign neoplasms. Accurate cytological diagnosis is straightforward when three characteristic components are present: oncocytes, either isolated or associated in clusters, lymphocytes and lymphoid cells and often an inflammatory/necrotic-like substance. Also, specific features of scintigraphy and radiological imaging contribute to the diagnosis of WT. WT is categorized according to Seifert G. et al in 4 types, depending on the proportions of the epithelial component and lymphoid stroma. Differential cytopathological and pathohistological diagnosis include other salivary gland lesions with lymphoid, oncocytic epithelial and cystic components. In some cases, such as the metaplastic WT variant, there are additional cytopathological and histological diagnostic difficulties. Moreover, bilateral, multicentric or multiple and infrequently seen extra-salivary localizations of WT are associated with further cytopathological diagnostic difficulties. Also, a rare possibility of malignant transformation of the epithelial or lymphoid component of WT as well as possible association with other primary tumours remains a challenge in accurate cytopathological and histological diagnosis of WT.

Observation Rather than Surgery for Benign Parotid Tumors: Why, When, and How

Surgery is the preferred treatment of benign parotid lesions, but it carries a risk of complications. Therefore, the approach toward the surgery of these lesions should seek to avoid complications. There are no guidelines or recommendations for when not to operate. Integration of comorbidities and other factors shift the scales from surgery toward observation in a small subset of patients presenting with parotid tumors. When observation is chosen, the patient should be followed frequently and cautiously, and the surgeon should be prepared to change strategy to surgical excision if in doubt.

Oncocytic papillary cystadenoma of the larynx: comparative study of ten cases and review of the literature

OBJECTIVE

Oncocytic papillary cystadenomas (OPCs) of the larynx are rare benign cystic lesions that usually present as supraglottic masses arising from the laryngeal ventricles. OPCs are found in patients older than 60 years, with a female predominance. Symptoms vary from asymptomatic to hoarseness, dyspnea, and dysphagia; often, they mimic a laryngocele. The treatment is surgical. Diagnosis is based on histopathologic examination.

MATERIALS AND METHODS

Surgical records for laryngeal masses diagnosed between 2005 and 2020 were searched retrospectively.

RESULTS

Ten patients were identified and included in the study. OPCs predominantly occurred in women (9/10), and the mean age at presentation was 73 years. Most patients (8/10) presented with hoarseness and were smokers. OPCs were localized in the ventricle in eight out of ten patients. Surgical treatment was performed in all cases, mostly using transoral endolaryngeal approach (9/10). Histopathologic examination revealed oncocytic cyst or oncocytic papillary cystadenoma (the former term being the older synonym for OPC).

CONCLUSION

OPCs present a separate clinicopathologic entity, distinct from other cystic laryngeal lesions. They have a characteristic location, age and sex group, microscopic appearance, and potential for local recurrence.

ETV6-NTRK3 translocation-associated low-grade mucinous bronchial adenocarcinoma: A novel bronchial salivary gland-type non-small cell lung cancer subtype

INTRODUCTION

NTRK fusion genes have been found in several solid tumors, among which NSCLC and sarcoma. Novel NTRK translocation-related tumors are still being discovered.

METHODS

We report a 49-year-old patient with a mass in the left lower lung lobe that was resected. This specimen was analyzed and sequenced using targeted DNA next generation sequencing (NGS) and anchored-multiplex-PCR (AMP) targeted RNA NGS.

RESULTS

On pathological evaluation, a peribronchial mucinous neoplasm with a unique morphology was found. RNA NGS analysis showed anETV6-NTRK3 translocation in a low-grade mucinous bronchial adenocarcinoma.

CONCLUSIONS

This entity represents a novel subtype of non-small cell lung cancer, which we would like to term 'ETV6-NTRK3 translocation-associated low-grade mucinous bronchial adenocarcinoma'.

A triple-classification radiomics model for the differentiation of pleomorphic adenoma, Warthin tumour, and malignant salivary gland tumours on the basis of diffusion-weighted imaging

AIM

To develop and validate a triple-classification radiomics model for the preoperative differentiation of pleomorphic adenoma (PA), Warthin tumour (WT), and malignant salivary gland tumour (MSGT) based on diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

Data from 217 patients with histopathologically confirmed salivary gland tumours (100 PAs, 68 WTs, and 49 MSGTs) from January 2015 to March 2019 were analysed retrospectively and divided into a training set (n=173), and a validation set (n=44). A total of 396 radiomic features were extracted from the DWI of all patients. Analysis of variance (ANOVA) and least absolute shrinkage and selection operator (LASSO) regression were used to select radiomic features, which were then constructed using three classification models, namely, logistic regression method (LR), support vector machine (SVM), and K-nearest neighbor (KNN). The diagnostic performance of the radiomics model was quantified by the receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) of the training and validation data sets.

RESULTS

The 20 most valuable features were investigated based on the LASSO regression. LR and SVM methods exhibited better diagnostic ability than KNN for multiclass classification. LR and SVM had the best performance and yielded the AUC values of 0.857 and 0.824, respectively, in the training data set and the AUC values of 0.932 and 0.912, respectively, in the validation data set of MSGT diagnosis.

CONCLUSION

DWI-based triple-classification radiomics model has predictive value in distinguishing PA, WT, and MSGT, which can be used for preoperative auxiliary diagnosis in clinical practice.

Clinical Significance of Histone Deacetylase (HDAC)-1, -2, -4 and -6 Expression in Salivary Gland Tumors

Salivary gland tumors (SGTs) comprise a group of rare neoplasms. Locally aggressive, recurrent and/or metastatic SGTs are notorious for their resistance to systemic therapy, making the need for carefully designed, prospective and randomized trials with useful predictive markers mandatory to define new effective therapeutic protocols. Histone Deacetylases (HDACs), are thought to play a crucial role in carcinogenesis. They affect the DNA structure, being also able to regulate its transcription, repair, and replication. This study aimed to evaluate-to our knowledge for the first time-the HDAC-1, -2, -4 and -6 immunohistochemical expression in SGTs and their potential use as prognostic biomarkers. Medical records and archival histopathological material of 58 (36 benign and 22 malignant) SGT patients were included in this study. The H-score was statistically correlated with the clinicopathological characteristics for all cases and patients' survival rate in malignant SGTs. HDAC-2 positivity was significantly associated with more prolonged overall survival (OS) of patients with malignant SGTs (p = 0.028), while HDAC-2 positivity and no HDAC-6 expression were associated with prolonged OS of patients with HG malignant SGT (p = 0.003 and p = 0.043, respectively). Additionally, a high HDAC-2 H-score was significantly associated with longer OS for HG malignant SGT patients (p = 0.027). In our study, HDAC-2 expression is a marker for good prognosis, whereas HDAC-6 expression indicated poor prognosis; thus, an inhibitor of HDAC-6 may be used to improve patients' survival.

Salivary Gland Pleomorphic Adenomas Presenting With Extremely Varied Clinical Courses. A Single Institution Case-Control Study

Objective

Pleomorphic adenomas (PAs) with divergent clinical behavior, differing from the vast majority of PAs, were distinguished. “Fast” PAs are characterized by an unexpectedly short medical history and relatively rapid growth. The reference group consisted of “slow” PAs with very stable biology and long-term progression. We divide the PA group as a whole into three subsets: “fast,” “normal,” and “slow” tumors. Our goal is a multifactorial analysis of the “fast” and “slow” PA subgroups.

Methods

Consecutive surgeries in a tertiary referral center, the Department of Otolaryngology and Laryngological Surgery, Poznan University of Medical Sciences, Poland, were carried out between 2002 and 2011. Out of 1,154 parotid tumors, 636 (55.1%) were PAs. The data were collected prospectively in collaboration with the Polish National Registry of Benign Salivary Gland Tumors. The main outcome measure was the recurrence rate in “fast” and “slow” PA subgroups. All surgical qualifications and surgeries were performed by two experienced surgeons.

Results

Slow PAs, compared to fast PAs, presented in older patients (53.25 ± 15.29 versus 47.92 ± 13.44 years). Multifactor logistic regression analysis with recurrence (yes/no) as the outcome variable, fast/slow as the predictor variable and age, gender, margin, FN status as covariates showed that fast PAs were significantly predicting recurrence vs. slow PAs (p = 0.035). Fast PAs were increasing the risk of PAs 10-fold vs. slow PAs, exp β = 10.20, CI₉₅ [1.66; 197.87]. The variables impacting relapse were recent accelerated growth of the tumor OR = 3.35 (SE = 0.56), p = 0.030, positive margins OR = 7.18 (SE = 0.57), p < 0.001, incomplete or bare capsule OR = 9.91 (SE = 0.53), p = 0.001 and location III OR = 3.12 (SE = 0.53), p = 0.033. In the multivariate model only positive margin was selected as the best predictor of relapse, OR = 5.01 (SE = 0.60), p = 0.007.

Conclusions

The simple clinical aspect of slow or fast PA progression is of great practical importance and can constitute a surrogate of the final histopathological information that is derived from the surgical specimen. The slow or fast nature of the PA to some extent indicates prognostic features such as recurrence risk. This finding requires correlation with histological and molecular features in further stages of research.

Cell adhesion molecules' altered profile in benign and malignant salivary gland tumors. The paradigm of beta4-integrin, desmoglein-2, ICAM-1 and CD44s

Background

Alterations in intercellular and cell-extracellular matrix connections contribute to tumour development. This study investigates the expression of specific cell adhesion molecules (CAMs) in salivary gland tumors (SGTs).

Methods

Formalin–fixed, paraffin– embedded tissue specimens of different types of 34 benign and 31 malignant SGTs and normal salivary glands were studied using Envision/HRP immunohistochemical technique for Desmoglein-2 (Dsg-2), beta4-integrin, CD44s and ICAM-1. Intensity of staining was evaluated in a semi-quantitative manner. Results were analyzed using Kendall’s τ and Spearman’s ρ as correlation criteria.

Results

Dsg-2 in intercellular space, beta4-integrin in cell-basal membrane, and CD44s in both types of contacts were strongly expressed in normal acinar and ductal cells, whereas ICAM-1 was expressed only at the endothelium and sparse stromal cells and monocytes. Strong correlation was found between Dsg-2 expression in adenomas and controls and between adenocarcinomas and controls. In adenomas, a distinct cytoplasmic presence of Dsg-2 was observed in addition to the usual membranous expression, with decreased expression in comparison with normal tissue. In malignant SGTs, Dsg-2 expression was absent. In most SGTs, beta4-integrin was expressed also with a distinct pattern, involving the cytoplasm and the unpolarised membrane, while CD44 was found only on the membrane. Strong correlation between beta4-integrin expression in adenomas and controls was noted, while CD44 expression was found to be correlated significantly between adenocarcinomas and controls (p < 0.001). Regarding ICAM-1, its expression was found increased in adenomas, with non-specific distribution in malignant SGTs and strong correlation between the histological subtypes and controls (p < 0.001).

Conclusion

The different expression profile of CAMs in SGTs could possibly suggest a role on their pathogenesis, representing a model of how neoplastic cells can take advantage of normal tissue architecture and cell-extracellular matrix interactions.

What is hiding behind S100 protein and SOX10 positive oncocytomas? Oncocytic pleomorphic adenoma and myoepithelioma with novel gene fusions in a subset of cases

Oncocytomas (OCs) in salivary glands are rare benign tumors composed of mitochondria-rich epithelial cells (oncocytes), mostly localized in the parotid gland. The treatment of choice is simple excision. Extensive oncocytic metaplasia of pleomorphic adenoma (PA) and myoepithelioma (ME) can be diagnostically challenging and may camouflage the correct diagnosis. These tumors should be treated more carefully compared with OC, given the risk of frequent recurrences and the possibility of malignant transformation. We have investigated 89 oncocytic lesions from our files, including OC (n = 74) and metaplastic oncocytic variant of PA/ME (n = 15). All OCs were stained for S100 protein and SOX10. The tumors with immunohistochemical expression of one or both markers were tested by next-generation sequencing (NGS). The NGS results were confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and/or fluorescence in situ hybridization (FISH). Ten cases originally diagnosed as OC, and 1 low-grade uncertain oncocytic tumor (11/74) revealed nuclear-cytoplasmic and/or nuclear positivity for S100 protein and/or SOX10, respectively. Fusion transcripts CHCHD7-PLAG1 and GEM-PLAG1 were found in 2 cases (1 fusion in each), and these were confirmed by RT-PCR and PLAG1 break-apart FISH probe, respectively. Another 5 cases were positive for PLAG1 rearrangement by FISH. In the control group of 15 oncocytic PA/ME, 4/15 tested tumors harbored gene fusions including NFT3-PLAG1, CHCHD7-PLAG1, FBXO32-PLAG1, and C1orf116-PLAG1 (1 fusion in each case) as detected by NGS. Two fusions were confirmed by RT-PCR, 1 case by FISH, and 1 case was not analyzable by FISH. We additionally tested 24 OCs negative for S100 protein and SOX10 by immunohistochemistry (IHC) and by FISH for rearrangement of PLAG1 gene, but none of them were positive. SOX10 and/or S100 protein immunopositivity in conjunction with rearrangement of the PLAG1 gene assisted in reclassification of a subset of oncocytomas as oncocytic variants of PA and ME. Therefore, we recommend to include S100 protein and SOX10 IHC when diagnosing tumors with predominantly oncocytoma-like differentiation. In addition, by NGS, 3 new gene fusions were detected in oncocytic ME, including NTF3-PLAG1, FBXO32-PLAG1, and GEM-PLAG1, and a new fusion C1orf116-PLAG1 was detected in oncocytic PA.

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.

Myeloid Sarcoma That Infiltrated a Preexisting Sebaceous Lymphadenoma in the Parotid Gland: Diagnostic Challenges and Literature Review

Myeloid sarcoma (MS) is a rarely encountered extramedullary localized tumor that is composed of immature myeloid cells. We reported an extremely rare case of MS with concurrent bone marrow (BM) involvement that invaded into a preexisting sebaceous lymphadenoma in the parotid gland and neck lymph nodes. Prompted by this case, we also present a literature review of MS invasion into salivary glands. A 62-year-old man was initially diagnosed with carcinoma that arose in a sebaceous lymphadenoma in the parotid gland, through a total parotidectomy with neck dissection. After an extensive histopathological review that included immunohistochemistry, a pathologic diagnosis of MS with infiltration into the sebaceous lymphadenoma with concurrent BM involvement was confirmed. MS is difficult to diagnose accurately; herein, we analyzed the clinical presentations and effectiveness of the various diagnostic methods with a review of the literature. There are 17 cases, including our case, reported in 13 studies. Of the cases in which the salivary glands were affected, 10 involved the parotid gland, six involved the submandibular gland, and one involved both. Isolated invasion of the salivary gland was found in one case of parotid gland invasion and three cases of submandibular gland invasion. In 13 cases, the salivary glands were affected by various other lesions. Although there were no incidences of isolated MS, six patients were diagnosed with secondary MS and eight patients with MS with BM involvement, including this case. The diagnosis of MS is difficult given its rarity, and a high index of suspicion and integrated radiologic and careful histopathologic evaluation are required. Most cases of MS infiltrating the salivary gland might be indicated by the possibility of BM involvement. MS with BM involvement predicts poor prognosis and the need for intensive systemic treatment.