Contrast-enhanced ultrasound in the evaluation of parotid gland lesions: an update of the literature

Current management and future challenges in salivary glands cancer

Salivary gland cancers (SGCs) are rare, accounting for less than 5% of all malignancies of the head and neck region, and are morphologically heterogeneous. The diagnosis is mainly based on histology, with the complementary aid of molecular profiling, which is helpful in recognizing some poorly differentiated, borderline, or atypical lesions. Instrumental imaging defines the diagnosis, representing a remarkable tool in the treatment plan. Ultrasound and magnetic resonance are the most common procedures used to describe the primary tumour. The treatment of SGCs is multimodal and consists of surgery, radiotherapy, and systemic therapy; each treatment plan is, however, featured on the patient and disease's characteristics. On 24 June 2022, in the meeting "Current management and future challenges in salivary gland cancers" many experts in this field discussed the state of the art of SGCs research, the future challenges and developments. After the meeting, the same pool of experts maintained close contact to keep these data further updated in the conference proceedings presented here. This review collects the insights and suggestions that emerged from the discussion during and after the meeting per se.

Contrast-Enhanced Ultrasound and Strain Elastography for Differentiating Benign and Malignant Parotid Tumors

OBJECTIVES

Preoperative differentiation between benign parotid tumors (BPT) and malignant parotid tumors (MPT) is crucial for treatment decisions. The purpose of this study was to investigate the benefits of combining contrast-enhanced ultrasound (CEUS) and strain elastography (SE) for preoperative differentiation between BPT and MPT.

METHODS

A total of 115 patients with BPT (n=72) or MPT (n=43) who underwent ultrasound (US), SE, and CEUS were enrolled. US and CEUS features and the elasticity score were evaluated. Receiver operating characteristic curve (ROC) analysis was used to assess the diagnostic performance of SE, CEUS, and SE + CEUS with respect to identifying MPT from BPT.

RESULTS

Solitary presentation, larger diameter, irregular shape, ill-defined margin, heterogeneous echogenicity, and calcification on US and higher elasticity score on SE had a significant association with malignancy. MPT also presented an unclear margin, larger size after enhancement, and "fast-in and fast-out" pattern on CEUS. The combination of SE and CEUS was effective for differentiating MPT from BPT (AUC: 0.88, 0.80-0.95), with a sensitivity of 86.0%, specificity of 88.9%, and accuracy of 87.8%, which were significantly higher than the values for SE (AUC: 0.75, 0.66-0.85) and CEUS (AUC: 0.82, 0.73-0.91) alone.

CONCLUSION

The combination of CEUS and SE is valuable for distinguishing MPT from BPT.

Intraoperative Visualization and Treatment of Salivary Gland Dysfunction in Sjögren's Syndrome Patients Using Contrast-Enhanced Ultrasound Sialendoscopy (CEUSS)

In sialendoscopy, ducts are dilated and the salivary glands are irrigated with saline. Contrast-enhanced ultrasound sialendoscopy (CEUSS), using microbubbles, may facilitate the monitoring of irrigation solution penetration in the ductal system and parenchyma. It is imperative to test CEUSS for its safety and feasibility in Sjögren's syndrome (SS) patients. CEUSS was performed on 10 SS patients. The primary outcomes were safety, determined by the occurrence of (serious) adverse events ((S)AEs), and feasibility. The secondary outcomes were unstimulated and stimulated whole saliva (UWS and SWS) flow rates, xerostomia inventory (XI), clinical oral dryness score, pain, EULAR Sjögren's syndrome patient reported index (ESSPRI), and gland topographical alterations. CEUSS was technically feasible in all patients. Neither SAEs nor systemic reactions related to the procedure were observed. The main AEs were postoperative pain (two patients) and swelling (two patients). Eight weeks after CEUSS, the median UWS and SWS flow had increased significantly from 0.10 to 0.22 mL/min (p = 0.028) and 0.41 to 0.61 mL/min (p = 0.047), respectively. Sixteen weeks after CEUSS, the mean XI was reduced from 45.2 to 34.2 (p = 0.02). We conclude that CEUSS is a safe and feasible treatment for SS patients. It has the potential to increase salivary secretion and reduce xerostomia, but this needs further investigation.

Histogram analysis of ultrasonographic images in the differentiation of benign and malignant parotid gland tumors

OBJECTIVE

We evaluated the diagnostic value of histogram analysis (HA) using ultrasonographic (US) images for differentiation among pleomorphic adenoma (PA), adenolymphoma (AL), and malignant tumors (MT) of the parotid gland.

STUDY DESIGN

Preoperative US images of 48 patients with PA, 39 patients with AL, and 17 patients with MT were retrospectively analyzed for gray-scale histograms. Nine first-order texture features derived from histograms of the tumors were compared. Area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic performance of texture features. The Youden index maximum exponent was used to calculate sensitivity and specificity.

RESULTS

Statistically significant differences were discovered in Mean and Skewness HA values between PA and AL (P<0.001), and in Mean values between AL and MT (P<0.001). However, comparison of PA and MT showed no statistically significant differences (P>0.01). Excellent discrimination was detected between PA and AL (AUC=0.802), and between AL and MT (AUC=0.822). The combination of Mean plus Skewness improved discrimination between PA and AL (AUC=0.823) with sensitivity values reaching 1.00. However, Mean plus Skewness applied to differentiate PA from AL and Mean values applied to distinguish AL and MT resulted in low specificity, indicating many false positive interpretations.

CONCLUSIONS

Histogram analysis is useful for differentiating PA from AL and AL from MT but not PA from MT.

Assessment of Parotid Gland Tumors by Means of Quantitative Multiparametric Ultrasound (mpUS)

OBJECTIVE

The preoperative diagnostical differentiation of parotid gland tumor (PGT) is not always simple due to several different entities. B-mode-ultrasound (US) remains the imaging modality of choice, while histopathology serves as the gold standard for finalizing the diagnosis. We aimed to evaluate the use of multiparametric US (mpUS) in the assessment of PGT.

METHODS

We included 97 PGTs from 96 patients. A standardized mpUS protocol using B-mode-US, shear-wave elastography (SWE), and standardized contrast-enhanced ultrasound (CEUS) was performed prior to surgical intervention. SWE was assessed by real-time measurement conducting a minimum of five measurements, while quantitative CEUS parameters were assessed with a post-processing perfusion software.

RESULTS

SWE allowed differentiation between benign PGT (Warthin's Tumor (WT) paired with lymph nodes (LN) and pleomorphic adenoma (PA)), and WT and LN were softer compared to PA. WT showed lower velocities than squamous cell carcinoma (SCC): the most common malignant PGT. CEUS parameters showed significant group differences between WT and PA, WT and malignant lesions, WT and SCC, WT paired with LN versus PA, and WT paired with LN versus SCC.

CONCLUSION

MpUS seems to be beneficial in the assessment of PGT characterization, with benign PGT appearing to be softer in SWE than tumors with malignant tendencies. The quantitative CEUS parameter shows higher perfusion in WT than in PA, and malignant PGTs are less vascularized than WTs.

Contrast-Enhanced Ultrasound in the Differentiation between the Most Common Benign Parotid Gland Tumors: A Systematic Review and Meta-Analysis

Recently, contrast-enhanced ultrasound (CEUS) has become a promising tool in distinguishing benign from malignant parotid gland tumors. However, its usefulness in differentiating various benign parotid tumors has not been determined so far. This study aimed to systematically review the literature to determine the utility of CEUS in the preoperative differentiation between pleomorphic adenomas (PAs) and Warthin's tumors (WTs) of the parotid gland. PubMed, Embase, and Cochrane were searched for English-language articles published until 21 July 2022. Fifteen studies were included. On CEUS examination, a significantly greater percentage of PAs displayed heterogeneous enhancement texture compared to WTs. Contrarily, the enhanced lesion size, the enhancement margin, and the presence of the enhancement rim did not differ significantly between the entities. Significantly longer normalized mean transit time (nMTT) and time to peak (TTP) were observed in PAs. Contrarily, the mean values of area under the curve (AUC) and time from peak to one half (TPH) were significantly higher for WTs. Due to the considerable overlap among the qualitative CEUS characteristics of PAs and WTs, the reproducible, investigator-independent quantitative CEUS measurements have a greater potential to distinguish PAs from WTs, which might influence the selection of an appropriate management strategy.

Correlations between Contrast-Enhanced Ultrasound Imaging and Histopathological Results in Salivary Gland Lesions

The purpose of this study was to search for correlations between contrast-enhanced ultrasound (CEUS) imaging and histopathological results in salivary gland lesions and to determine the accuracy of CEUS in the preoperative differentiation of salivary gland tumours according to postoperative histopathological results. The study included 54 consecutive patients with 63 salivary gland lesions who underwent CEUS examination prior to surgical treatment at the Department of Otolaryngology, Medical University of Łódź (Poland) in 2019–2022. The accuracy of CEUS in differential diagnostics of salivary gland lesions was later verified against final histological diagnosis. Among 63 salivary gland lesions, 26 were categorized as malignant or with malignant potential, and 37 were benign. There was a correlation between professional photographs of CEUS imaging and microscope slides containing postoperative specimens. A strong heterogeneous enhancement was observed mainly in benign lesions, with while weak heterogeneity mostly among the malignant or with malignant potential lesions. A pattern of contrast enhancement in specific structures reflected histopathological images. These results suggest that contrast-enhanced ultrasonography is a promising tool for the preoperative diagnostics of salivary gland lesions.

Clinical Diagnostic Application of Contrast-Enhanced Ultrasound in Focal Lesions of the Salivary Glands

OBJECTIVES

To evaluate the clinical diagnostic value of contrast-enhanced ultrasound (CEUS) for focal benign and malignant lesions of the salivary glands, as well as for common benign lesions.

METHODS

A total of 91 patients with focal lesions of the salivary glands were included in this study. In this study, CEUS was used to study the differential diagnosis of focal benign and malignant lesions of the salivary gland and the most common benign tumors, that is, pleomorphic adenoma (PA) and adenolymphoma.

RESULTS

The differences between focal benign and malignant lesions in the salivary glands were statistically significant (P < .05) in terms of qualitative CEUS indicators, enhancement pattern, enhancement homogeneity, enhancement margin, and enhanced lesion size, whereas the differences were not statistically significant (P > .05) in terms of wash-in and wash-out pattern, enhancement degree. Blurred margins and increased size of the lesion after enhancement are two CEUS features independently associated with focal malignant lesions of the salivary gland. The differences between salivary gland PA and adenolymphoma were statistically significant (P < .05) in terms of wash-in pattern, enhancement degree, enhancement homogeneity, and enhancement pattern, but not in terms of wash-out pattern, enhancement margin, and enhanced lesion size (P > .05).

CONCLUSIONS

As an economical, convenient, and safe imaging method, CEUS has important clinical value in distinguishing benign and malignant salivary glands.

Perfusion analysis of benign parotid gland tumors by contrast-enhanced ultrasonography (CEUS)

BACKGROUND

Diagnosis of parotid gland tumors is sometimes challenging due to their diversity and pleomorphic histological appearance. B-scan sonography along with color-coded duplex sonography is the gold standard in the diagnostic workup of these lesions, whereas histopathology is to date the gold standard for the final diagnosis. To date no single imaging technique provides the chance for an art-diagnosis with highly diagnostic accuracy. Contrast enhanced ultrasonography (CEUS) on the other hand provides information of the perfusion down to the capillary level. Currently there are only a few papers published with systematical examination of the perfusion in benign parotid gland tumors and its diagnostic significance.

PATIENTS AND METHODS

One hundred patients with a parotid gland tumor were examined. The examinations included conventional B-scan sonography, color-coded duplexsonography along with contrast enhanced ultrasonography (CEUS). B-scan sonographic parameters, i.e. echogenicity, shape, size, demarcation, and borders of a lesion along with vascularization estimated by color-coded-duplexsonography were analyzed. Analysis of quantitative CEUS parameters was performed using 8 regions of interest (ROI), which were standardized located throughout the entire tumors. The perfusion parameters were analyzed for particular tumor entities. Qualitative CEUS analysis with estimating the perfusion pattern was additionally performed.

RESULTS

Histological examination revealed benign tumors in 92 cases, with pleomorphic adenomas and Warthin´s tumors were the most frequent entities. Malignant conditions were found in 8 cases. CEUS revealed a centripetal perfusion pattern in malignant tumors significantly more frequently than in benign tumors. CEUS showed a significant heterogenic perfusion in all tumors, with a higher perfusion in the medial parts of the tumors and in some cases also in the center. Perfusion patterns of PA and WT were different. WT displayed centrifugal, centripetal, and central diffuse perfusion more often than PA, whereas in PA perfusion often was limited to the capsule or periphery. Oncocytoma had the highest perfusion values. Intraglandular cysts showed no intralesional perfusion.

CONCLUSIONS

CEUS analysis in different parts of benign tumors revealed a significant heterogeneity in tumor perfusion. Some perfusion pattern could be identified which might be characteristic for particular lesions. Based on this, the diagnostic accuracy of CEUS in the differential diagnosis of parotid gland tumors can be increased. In particular, the perfusion analysis within the tumors using ROIs located standardized throughout the entire tumor provides additional information which are important for the art diagnosis and in differentiation of tumor entity.

Performance Evaluation of Multiple Ultrasonographical Methods for the Detection of Primary Sjögren's Syndrome

Major salivary gland ultrasonography (SGUS) is increasingly being recognized as having critical roles in differentiating primary Sjögren’s syndrome (pSS) from other connective tissue disorders. Contrast-enhanced ultrasonography (CEUS) has been reported to evaluate microvascularity of lesions in different tissues with objective angiographic index, eliminating the observer-dependent defect of ultrasonography. However, there are few relevant studies concentrating on the application of CEUS in the diagnosis and assessment for pSS, and their clinical utility prospect remains uncertain. In this study, a total of 227 eligible patients were enrolled, including 161 pSS and 66 non-pSS patients with comprehensive ultrasonographic evaluation of the parotid and submandibular glands, including grayscale ultrasonography, color Doppler sonography (CDS), and CEUS. Compared with non-pSS, pSS patients had significantly higher grayscale ultrasound (US) scores and CDS blood grades in the parotid gland and significantly higher grayscale US and CEUS scores in the submandibular glands. Diagnostic model combining ultrasonographic signatures, anti-SSA/Ro60, and keratoconjunctivitis sicca (KCS) tests showed a remarkable discrimination [mean area under the curve (AUC)0.963 in submandibular glands and 0.934 in parotid glands] for pSS, and the nomogram provided excellent prediction accuracy and good calibration in individualized prediction of pSS. A combination of multiple ultrasonographical examinations of the major salivary glands (SGs) is a promising technique that may be used as a practical alternative to minor SG biopsy in the detection of pSS.

Rupture of the Pleomorphic Adenoma of the Parotid Gland: What to Know before, during and after Surgery

Background: We assessed the cases of intraoperative spillage of primary pleomorphic adenomas (PPAs) of the parotid gland in the literature, comparing them with our own cases. We aim to explain how the surgeon should manage a spillage during surgery (i.e., how to avoid spreading the contents that are coming out of the tumor). We also aim to investigate whether or not spillage is linked to a higher rate of PPA recurrence. Methods: We collected surgical and pathological reports, taking data on capsular ruptures and the spillage of tumors. Results: Intraoperative tumor spillage and tumor rupture occurred in 34/202 cases. There were three recurrences after a mean of 3.7 years (mean follow-up duration: 10.3 years). One recurrence happened to a patient who had an intraoperative tumor spillage, and two more recurrences happened to patients who did not have spillage. Conclusion: We believe that the real number of the events of spillage is underestimated and underreported by surgeons. Capsular rupture must always be avoided, and secure resection margins must always be pursued, independent of the type of parotidectomy being performed. Features that increase the risk of recurrence are an intraoperative rupture and the presence of satellite nodules (as recorded in the pathologist’s report). In these cases, patients need a longer follow-up period.

[Perfusion analysis in parotid gland tumors using contrast-enhanced ultrasound (CEUS)]

OBJECTIVE

The diagnosis of parotid gland tumors is challenging due to their rarity and heterogenity. Neither conventional ultrasound nor magnetic resonance imaging (MRI) nor computed tomography (CT) allow a reliable pretherapeutic diagnosis. In addition to conventional ultrasound, contrast-enhanced ultrasound (CEUS) enables a more detailed assessment of perfusion in parotid gland tumors, thereby improving evaluation of this tumor entity. Extensive studies with analysis of perfusion characteristics in different regions of interest (ROI) in parotid gland tumors are currently lacking. This study analysed and compared perfusion parameters in different intratumoral areas of malignant and benign parotid gland tumors using CEUS.

MATERIALS AND METHODS

A total of 100 patients with tumors in the parotid gland were examined using B‑mode sonography, colour Doppler sonography and CEUS. The parameters magnitude, echogenicity, demarcation, vascularisation and in particular perfusion characteristics were measured and analysed. Analysis of quantitative CEUS parameters was performed using a specific method for perfusion analysis with certain ROI, which were allocated in a standardized manner in the entire parotid gland tumors. The perfusion parameters were compared between intratumoral ROI in the tumors and between particular tumor entities. Qualitative CEUS analysis with an estimation of perfusion patterns was additionally performed.

RESULTS

Histologically benign tumors were found in 92 cases, and malignant tumors in eight cases. CEUS analysis of perfusion patterns revealed a centripetal perfusion pattern in malignant tumors significantly more frequently than in benign tumors. In the perfusion analysis of quantitative CEUS parameters, all tumors showed higher perfusion intensities in the peripheral ROI. In benign tumors, more differences in perfusion intensity between the intratumoral ROIs were detected compared to malignant tumors.

CONCLUSION

The perfusion parameters (centripetal perfusion pattern; area under the curve) evaluated in this study have the potential to improve pretherapeutic diagnostics of parotid gland tumors in terms of differentiation of tumor entity. Further studies with larger patient cohorts are required for subsequent investigation and validation of the diagnostic accuracy of particular parameters to detect perfusion patterns potentially specific to particular tumor entities.

Application of ultrasound and contrast-enhanced ultrasound to distinguish salivary focal inflammatory masses from malignant masses: A retrospective observational study

BACKGROUND

The aim was to retrospectively analyze the ultrasonographic and clinical characteristics of focal inflammatory masses and malignant masses of salivary gland by using B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) for differential analysis.

METHODS

The features of US and CEUS were retrospectively analyzed for 19 cases of focal salivary inflammatory masses and 45 cases of malignant salivary masses. All cases were confirmed by pathohistological examination.

RESULTS

On B-mode US, the incidence of expansive growth patterns of malignant salivary masses (44.4%, 20/45) was significantly higher than that of focal salivary inflammatory masses (15.8%, 3/19) (p = 0.029). The rate of lymphadenopathy surrounding salivary glands of malignant salivary masses (42.2%, 19/45) was significantly higher than that of focal salivary inflammatory masses (15.8%, 3/19) (p = 0.042). On CEUS, clear enhancement margins were more common in malignant salivary masses (44.4%, 20/45) compared to focal salivary inflammatory masses (15.8%, 3/19) (p = 0.029); Rapid washout was more common in malignant salivary masses (82.2%, 37/45) than focal salivary inflammatory masses (31.6%, 6/19) (p <  0.001). Rapid washout on CEUS and craniocaudal diameter were independent predictive factors in differentiating salivary inflammatory masses and malignant masses according to binary logistic regression analysis. US and CEUS achieved a sensitivity of 80.0%, a specificity of 78.9%and an accuracy of 80.0%for discrimination between salivary inflammatory masses and malignant masses.

CONCLUSION

Therefore, a multimodal ultrasonographic pathway combining clinical manifestations, B-mode US and CEUS was needed to differentiate between salivary focal inflammatory masses and malignancies to avoid unnecessary biopsies.

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

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

A case report of a rare nasopharyngeal myoepithelial dominant pleomorphic adenoma

•

Majority of pleomorphic adenoma arise from the major salivary glands but tumors arising from the minor salivary glands have been reported as well.

•

Pleomorphic adenoma presents most commonly in the third to the sixth decades of life

•

Surgical excision is the mainstay of treatment in pleomorphic adenoma as they can grow to giant sizes if left untreated.

Introduction

Pleomorphic adenoma is the most common benign salivary gland neoplasm. The majority of cases occur in the major salivary glands; however, they can also originate from the minor salivary glands. The nasopharynx is an uncommon site, but it has been reported in the literature. The characteristic difference of our report from the literature is the young age of our patient and his previous unremarkable medical or surgical history.

The objective of this report is to present a case of salivary gland pleomorphic adenoma, discuss radiological and histopathological findings and treatment options.

Case presentation

Herein we report a case of a 25-year-old male patient presenting with a long-term history of snoring, mouth breathing, and progressive left nasal obstruction. After examining the patient and confirming the diagnosis, patient successfully underwent tumor resection using a combined transnasal/transoral endoscopic approach with no complications following surgery and significant improvement of the previously reported symptoms.

Discussion

Pleomorphic adenoma of the minor salivary glands can occur anywhere throughout the distribution sites of these glands such as: along the upper aerodigestive tract, parapharyngeal fat spaces, soft palate, the sinonasal, and nasopharyngeal areas.

Conclusion

The occurrence of pleomorphic adenoma in uncommon sites has been reported in the literature, and the nasopharynx is considered to be one of these uncommon sites. The mainstay of treatment for nasopharyngeal pleomorphic adenoma is surgical excision as they can grow to giant sizes if left untreated.

Cross-sectional imaging and cytologic investigations in the preoperative diagnosis of parotid gland tumors - An updated literature review

An accurate preoperative diagnosis of parotid tumors is essential for the selection and planning of surgical treatment. Various modern cross-sectional imaging and cytologic investigations can support the differential diagnosis of parotid tumors. The aim of this study was to achieve a comprehensive and updated review of modern imaging and cytologic investigations used in parotid tumor diagnosis, based on the latest literature data. This literature review could serve as a guide for clinicians in selecting different types of investigations for the preoperative differential diagnosis of parotid tumors. Magnetic resonance imaging (MRI) with its dynamic and advanced sequences is the first-line imaging investigation used in differentiating parotid tumors. Computed tomography (CT) and positron emission tomography (PET)-CT provide limited indications in differentiating parotid tumors. Fine needle aspiration biopsy and core needle biopsy can contribute with satisfactory results to the cytological diagnosis of parotid tumors. Dynamic MRI with its dynamic contrast-enhanced and diffusion-weighted sequences provides the best accuracy for the preoperative differential diagnosis of parotid tumors. CT allows the best evaluation of bone invasion, being useful when MRI cannot be performed, and PET-CT has value in the follow-up of cancer patients. The dual cytological and imaging approach is the safest method for an accurate differential diagnosis of parotid tumors.

Narrative review of multiparametric ultrasound in parotid gland evaluation

Disorders affecting parotid gland represent a heterogeneous group comprising congenital, inflammatory and neoplastic diseases which show a focal or diffuse pattern of appearance. The differentiation of neoplastic from non-neoplastic conditions of parotid glands is pivotal for the diagnostic imaging. Frequently there is evidence of overlapping between the clinical and the imaging appearance of the various pathologies. The parotid gland is also often object of study with the combination of different techniques [ultrasound-computed tomography-magnetic resonance imaging (US-CT-MRI), ex.]. Compared to other dominant methods of medical imaging, US has several advantages providing images in real-time at lower cost, and without harmful use of ionizing radiation and of contrast enhancement. B-mode US, and the microvascular pattern color Doppler are usually used as first step evaluation of parotid lesions. Elastography and contrast-enhanced US (CEUS) has opened further possible perspectives to improve the differentiation between benign and malignant parotid lesions. The characterization of the parotid tumors plays a crucial role for their treatment planning and for the prediction of possible surgical complications. We present, here an updated review of the most recurrent pathologies of parotid gland focusing on the diagnostic power of multiparametric US including CEUS and ultrasound elastography (USE); limitations, advantages and the main key-points will be presented.

Intraoperative visualisation and treatment of salivary glands in Sjögren's syndrome by contrast-enhanced ultrasound sialendoscopy (CEUSS): protocol for a phase I single-centre, single-arm, exploratory study

INTRODUCTION

We established a promising sialendoscopic treatment for in vivo enhancement of salivation in salivary glands affected by Sjögren's syndrome (SS). In this technique, the ducts of the salivary glands are irrigated with saline and steroids. This allows for dilatation of ductal strictures and removal of debris. Unfortunately, it is not possible to assess the delivery and penetration of saline or medications in the ductal system and parenchyma. To address this problem, we will conduct contrast-enhanced ultrasound sialendoscopy (CEUSS) using sulphur hexafluoride microbubbles. To the best of our knowledge, microbubbles have never been used for the treatment of salivary glands in SS. It is, therefore, imperative to test this application for its safety and feasibility.

METHODS AND ANALYSIS

A single-arm phase I study will be performed in 10 SS patients. Under local anaesthesia, ultrasound (US) guided infusion of the parotid and submandibular glands with microbubbles will be performed. Continuous US imaging will be used to visualise the glands, including the location of strictures and occlusions. Main outcomes will be the evaluation of safety and technical feasibility of the experimental treatment. Secondary outcomes will consist of determinations of unstimulated whole mouth saliva flow, stimulated whole mouth saliva flow, stimulated parotid saliva flow, clinical oral dryness, reported pain, xerostomia, disease activity, salivary cytokine profiles and clinical SS symptoms. Finally, salivary gland topographical alterations will be evaluated by US.

ETHICS AND DISSEMINATION

Ethical approval for this study was obtained from the Medical Ethics Committee of the Amsterdam University Medical Centre, Amsterdam, The Netherlands (NL68283.029.19). data will be presented at national and international conferences and published in a peer-reviewed journal. The study will be implemented and reported in line with the Standard Protocol Items: Recommendations for Interventional Trials' statement.

TRIAL REGISTRATION NUMBERS

The Netherlands Trial Register: NL7731, MREC Trial Register: NL68283.029.19; Pre-results.

[CME Sonography 92: Nodes on the Neck]

CME Sonography 92: Nodes on the Neck Abstract. Nodules on the neck can be discovered accidentally when looking in the mirror, or due to pain that may be acute or gradual. The clinical examination is helpful to estimate the localization or to assign the nodule to a specific organ and assess its consistency and mobility. A sonography is very helpful in most cases as there are typical findings related to the thyroid gland, findings based on lymph nodes, changes in the tonsils, vessels and salivary glands. In some cases, the ultrasound must be supplemented by fine needle puncture.

Multiparametric ultrasound evaluation of parotid gland tumors: B-mode and color Doppler in comparison and in combination with contrast-enhanced ultrasound and elastography. A case report of a misleading diagnosis

Preoperative characterization of parotid gland tumors using imaging or cytological examination (fine-needle aspiration cytology) has a strong clinical and therapeutic impact, but it is often difficult due to the tumors' histological heterogeneity. The recent introduction of contrast-enhanced ultrasound (CEUS) and elastography, in the context of multiparametric ultrasound evaluation, contributed to improving the preoperative diagnosis of many diseases affecting the liver, breast, and thyroid, as well as other organs. However, limited evidence is available on the use and the diagnostic power of these techniques in parotid gland neoplasms. In this paper, we present a case of a parotid lesion that highlights the importance of a complete workup using multiparametric ultrasound evaluation, including CEUS and elastography, to identify malignant tumors of the parotid gland.

Percutaneous drainage of a parotid gland abscess under contrast-enhanced ultrasound guidance: A case report

A parotid gland abscess is uncommon and if not responding to conservative management, requires surgical intervention. However, surgery is invasive with the risk of complicating facial nerve damage and possible poor cosmetic outcome. We present a case of a parotid gland abscess in association with an underlying Warthin's tumour requiring percutaneous drainage, as patient co-morbidity precluded a safe surgical approach. Percutaneous drainage was aided by a contrast-enhanced ultrasound examination, which permitted delineation of the fluid aspects of the collection from the underlying tumour and allowed successful percutaneous ultrasound-guided aspiration without complication.

The differential diagnosis of parotid gland tumors with high-resolution ultrasound in otolaryngological practice

The aim of the study is to define the utility of ultrasound (US) in differentiating benign from malignant parotid tumors as well as pleomorphic adenomas (PA) from monomorphic adenoma (MA). Seventy-two consecutive parotid gland tumors were analysed with high-resolution ultrasonography (12 MHz) with color Doppler imagining. The histopathological diagnosis was confirmed after parotidectomy for each lesion. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for the US were established. Receiver operating characteristic curves were constructed to determine the predictive values of echogenicity, heterogeneity, and vascularity on color Doppler. Area under the curve (AUC) was calculated for each parameter considered. The analysed material included 27 MA, 26 PA, 1 basal cell adenoma, 8 inflammatory conditions, and 10 malignant neoplasms. The sensitivity, specificity, and accuracy of US in differentiation of malignant from benign lesions in the parotid gland were 60, 95.2, and 90.3%, respectively. The predictive values were: PPV 66.8% and NPV 93.6%. Differentiating diagnoses between PA and MA with US resulted in a sensitivity of 61.5%, specificity of 81.5%, and accuracy of 73.1%. The predictive values were: PPV 50% and NPV 68.8%, respectively. For distinguishing malignant from benign tumors, the highest AUC values noted were for heterogeneity and vascularization (0.8 and 0.743, respectively). The AUC values were the highest for hypoechogenicity and vascularization in separating PA from MA (0.718 and 0.685, respectively).