Imaging of salivary gland tumours

Intracranial extension of parotid adenoid cystic carcinoma presenting as trigeminal neuralgia: A case report

Being rare malignancies, parotid gland adenocarcinomas are most significantly represented by the ACC subtype due to their aggressive nature and propensity for PNI. We present a case of a 56-year-old male with right-sided trigeminal neuralgia and facial palsy, diagnosed with ACC of the parotid gland with intracranial extension. Tumor progression occurred with brain, lung, and liver metastases, so he was placed on palliative care despite chemotherapy. This case underscores the diagnostic and management challenges associated with ACC with PNI.

Advances in Targeted and Systemic Therapy for Salivary Gland Carcinomas: Current Options and Future Directions

Salivary gland carcinomas (SGCs) represent a rare and heterogeneous group of malignancies accounting for 3-6% of all head and neck cancers. While surgical resection and radiotherapy remain the standard for locoregional control, systemic treatment is indicated for recurrent or metastatic disease. Advances in molecular profiling have identified actionable targets such as NTRK gene fusions, HER2, immune checkpoint regulators, androgen receptors, and RET receptors. These have facilitated the development of targeted therapies, including TRK inhibitors, HER2-directed agents, and androgen receptor modulators, as well as emerging combinations of immunotherapy and chemotherapy. Despite these advancements, challenges such as resistance mechanisms and limited therapeutic efficacy persist. Overall response rates remain relatively low across most systemic therapies, reflecting a persistent unmet clinical need. This review discusses the current landscape of treatment options and explores promising clinical trials and future directions to enhance outcomes for patients with SGCs.

Heterotopic submandibular gland with herniation through the mylohyoid boutonnière: a unique radiological case

PURPOSE

To describe a rare case of heterotopic submandibular gland (SMG) tissue herniating through the mylohyoid boutonnière into the anterior submandibular space, diagnosed using imaging, and to provide insights into its clinical implications.

METHODS

A 59-year-old male with a history of smoking and type 2 diabetes presented with new-onset hoarseness. Imaging, including contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), was performed. The lesion's imaging characteristics, location, and tissue composition on CT and MRI were analyzed, and differential diagnoses were considered.

RESULTS

CT and MRI revealed a well-defined soft tissue lesion in the right anterior submandibular space, exhibiting features consistent with ectopic SMG tissue. On MRI, the lesion was iso- to slightly hyperintense compared to surrounding muscle tissue and showed ductal structures leading to the sublingual space, with a discontinuity in the mylohyoid muscle. No malignancy or other pathologies were identified, and the patient's hoarseness improved with treatment for dyspepsia.

CONCLUSIONS

This case highlights the diagnostic value of imaging in identifying rare anatomical anomalies like heterotopic SMG with herniation through the mylohyoid boutonnière. Accurate diagnosis can prevent unnecessary procedures and guide appropriate management.

Imaging Spectrum of Extrathyroidal Neck Masses

ABSTRACT

Extrathyroidal masses in the anterolateral neck are frequently encountered in the adult population and may represent a diagnostic dilemma. These neck masses can result from a diverse array of pathologies including congenital, inflammatory, infectious, and neoplastic causes. Relevant medical history and physical examination are essential to complement the imaging findings. Ultrasound (US) plays an important role in the initial evaluation of neck masses due to its reliability, availability, safety and cost-effectiveness. It can confirm or exclude the presence of a mass and initially characterize it as solid or cystic. Sonographically assessing the relationship of a mass to adjacent cervical anatomy can facilitate a more targeted differential diagnosis. US also effectively guides fine needle aspirations and/or biopsies of accessible lesions. Multimodality imaging is reserved for problem-solving complex cases and presurgical planning. The anterolateral neck masses are categorized into midline/paramedian lesions, salivary gland pathologies, and other soft tissue lesions. Midline and paramedian lesions include thyroglossal duct pathologies, ectopic thyroid tissue, and parathyroid adenomas. Salivary gland pathologies include obstructive/inflammatory processes, benign and malignant neoplasms, and systemic diseases. This pictorial essay presents clinical features and sonographic characteristics of extrathyroidal masses in the anterolateral neck with a brief discussion of other imaging modalities.

Prediction of High-risk Capsule Characteristics for Recurrence of Pleomorphic Adenoma in the Parotid Gland Based on Habitat Imaging and Peritumoral Radiomics: A Two-center Study

RATIONALE AND OBJECTIVES

This study aims to develop and validate an ultrasoundbased habitat imaging and peritumoral radiomics model for predicting high-risk capsule characteristics for recurrence of pleomorphic adenoma (PA) of the parotid gland while also exploring the optimal range of peritumoral region.

MATERIALS AND METHODS

Retrospective analysis was conducted on 325 patients (171 in training set, 74 in validation set and 80 in testing set) diagnosed with PA at two medical centers. Univariate and multivariate logistic regression analyses were performed to identify clinical risk factors. The tumor was segmented into four habitat subregions using K-means clustering, with peri-tumor regions expanded at thicknesses of 1/3/5mm. Radiomics features were extracted from intra-tumor, habitat subregions, and peritumoral regions respectively to construct predictive models, integrating three machine learning classifiers: SVM, RandomForest, and XGBoost. Additionally, a combined model was developed by incorporating peritumoral features and clinical factors based on habitat imaging. Model performance was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). SHAP analysis was employed to improve the interpretability.

RESULTS

The RandomForest model in habitat imaging consistently outperformed other models in predictive performance, with AUC values of 0.881, 0.823, and 0.823 for the training set, validation set, and testing set respectively. Incorporating peri-1mm features and clinical factors into the combined model slightly improved its performance, resulting in AUC values of 0.898, 0.833, and 0.829 for each set. The calibration curves and DCA exhibited excellent fit for the combined model while providing great clinical net benefit.

CONCLUSION

The combined model exhibits robust predictive performance in identifying high-risk capsule characteristics for recurrence of PA in the parotid gland. This model may assist in determining optimal surgical margin and assessing patients' prognosis.

Pleomorphic Adenoma of the Palate: A Detailed Case Report and Surgical Outcome

Pleomorphic adenoma is the most common salivary gland neoplasm, accounting for a significant proportion of both major and minor salivary gland tumors. While it most frequently arises in the parotid or submandibular glands, it can occasionally present as an intraoral mass over the palate or lip when originating from the minor salivary glands. A palatal pleomorphic adenoma typically presents as a painless, gradually enlarging mass on the posterior lateral aspect of the palate. This article discusses a case of a palatal pleomorphic adenoma, which was successfully managed with surgical excision.

A Method for Sensitivity Analysis of Automatic Contouring Algorithms Across Different MRI Contrast Weightings Using SyntheticMR

Background

Currently, a majority of institution-specific automatic MRI-based contouring algorithms are trained, tested, and validated on one contrast weighting (i.e., T2-weighted), however their actual performance within this contrast weighting (i.e., across different repetition times, TR, and echo times, TE) is under-investigated and poorly understood. As a result, external institutions with different scan protocols for the same contrast weighting may experience sub-optimal performance.

Purpose

The purpose of this study was to develop a method to evaluate the robustness of automatic contouring algorithms to varying MRI contrast weightings.

Methods

One healthy volunteer and one patient was scanned using SyntheticMR on the MR-Simulation device. The parotid and submandibular glands in these subjects were contoured using an automatic contouring algorithm trained on T2-weighted MRIs. For ground truth manual contours, two radiation oncology residents and one pre-resident physician were recruited and their STAPLE consensus was determined. A total of 216 different MRI TR and TE combinations were simulated across T1-, T2-, and PD-weighted contrast ranges using SyntheticMR's post-processing software, SyMRI. Comparisons between automatic contouring algorithm contours and the ground truth were determined using the Dice similarity coefficient (DSC) and 95th percentile Hausdorff distance (HD95).

Results

Notable differences in the automatic contouring model's performance were seen across the contrast-weighted range, even within the T2-weighted range. Further, some models even performed as well or better across subsets of the T1-weighted range. The PD-weighted range saw the worst performance. The range of discrepancy in DSC and HD95 exceeded 0.2 and 3.66 mm, respectively, in some structures. In the T2-weighted contrast region where the model was trained, 100%, 40%, 24%, and 57% for the DSC in the left parotid, right parotid, left submandibular, and right submandibular gland, respectively, exceeded interobserver variability.

Conclusions

This study demonstrates the variable performance of MRI-based automatic contouring algorithms across varying TR and TE combinations. This methodology could be applied in future studies as a method for evaluating model sensitivity, out of distribution detection ability, and performance drift.

Examination of parotid gland in diabetics with ultrasound elastography and microvascular imaging

BACKGROUND

Diabetes mellitus is a prevalent metabolic disorder that can result in the non-enflamatuar enlargement of the parotid gland. It is recognised as a condition that can impair microvascular perfusion.

MATERIAL AND METHODS

The parotid glands of 38 individuals with diabetes and 38 healthy controls were examined bilaterally using ultrasound to assess parameters of volume, stiffness and microvascularity.

RESULTS

A statistically significant increase in parotid gland volume and a statistically significant decrease in microvascularity were observed in diabetic patients. Furthermore, a statistically significant increase in parotid gland volume was noted in diabetic individuals who were using antidiabetic drugs in comparison to non-users. A significant negative correlation was identified between the duration of exposure to diabetes and microvascularity.

CONCLUSIONS

Ultrasonographic imaging can be used to assess the dimensions and microvascularity of the parotid gland.

Close relationship with the glandular capsule: a highly sensitive diagnostic indicator of major salivary gland metastatic malignancies in ultrasound

OBJECTIVES

To investigate the ultrasound (US) characteristics of metastatic malignancies (MM) in the major salivary glands and to assess the diagnostic value of the close relationship with the glandular capsule in identifying MM.

METHODS

From January 2016 and April 2022, 122 patients with major salivary gland malignancies, including 20 patients with MM and 102 patients with primary malignancies (PM) confirmed by histopathological examination, were enrolled in this study. Their clinicopathologic and US data were recorded and analysed. The diagnostic performance of the close relationship with the glandular capsule for differentiating MM from PM was analysed.

RESULTS

The mean age of MM were older than that of PM (59.50 ± 14.57 vs. 49.96 ± 15.73, P = .013). Compared with PM patients, MM were associated with a higher prevalence of local pain symptoms (P = .007) and abnormal facial nerve function (P < .001). MM were also more frequently characterized by unclear borders, rough margins, irregular shapes, heterogeneous internal echos, absence of cystic areas, presence of calcifications, close relationship with the glandular capsule, and US-reported positive cervical lymph nodes (all P < .05). The close relationship with the glandular capsule showed to be a good indicator in distinguishing between MM and PM, with an area under the receiver operating characteristic curve of 0.863, a sensitivity of 100%, a specificity of 72.5%, and an accuracy of 92.2%. Positive and negative predictive were calculated at 41.7% and 100%, respectively.

CONCLUSIONS

The US finding of a close relationship with the glandular capsule is a highly sensitive diagnostic indicator for MM. Following this finding, US-guided needle biopsy should be recommended to further confirm the diagnosis.

Revealing Enigma in Parotid Gland: Venolymphoma-A Rare Case Report

Venolymphoma (VL) is a benign condition of oral cavity, but it is misdiagnosed as pleomorphic adenoma. Exact diagnosis can be made only after histopathological examination. In this report the author has presented a case of a 45-year-old male patient with VL of right parotid which was operated. The treatment indicated was complete excision of the lesion, which showed an excellent prognosis with low recurrence rate.

Pediatric Salivary Gland Pathology

Benign and malignant salivary gland disorders are uncommon in the pediatric population; however, these can be frequently seen in pediatric otolaryngology or oral and maxillofacial surgery practices. The astute clinician should be aware of the clinical presentation, diagnosis, and management options for common inflammatory, infectious, benign, and malignant disorders of salivary glands.

Current Developments in Diagnosis of Salivary Gland Tumors: From Structure to Artificial Intelligence

Salivary glands tumors are uncommon neoplasms with variable incidence, heterogenous histologies and unpredictable biological behaviour. Most tumors are located in the parotid gland. Benign salivary tumors represent 54-79% of cases and pleomorphic adenoma is frequently diagnosed in this group. Salivary glands malignant tumors that are more commonly diagnosed are adenoid cystic carcinomas and mucoepidermoid carcinomas. Because of their diversity and overlapping features, these tumors require complex methods of evaluation. Diagnostic procedures include imaging techniques combined with clinical examination, fine needle aspiration and histopathological investigation of the excised specimens. This narrative review describes the advances in the diagnosis methods of these unusual tumors-from histomorphology to artificial intelligence algorithms.

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.

Heterogeneous PSMA ligand uptake inside parotid glands

The purpose of this investigation is to quantify the spatial heterogeneity of prostate-specific membrane antigen (PSMA) positron emission tomography (PET) uptake within parotid glands. We aim to quantify patterns in well-defined regions to facilitate further investigations. Furthermore, we investigate whether uptake is correlated with computed tomography (CT) texture features.

METHODS

Parotid glands from [18F]DCFPyL PSMA PET/CT images of 30 prostate cancer patients were analyzed. Uptake patterns were assessed with various segmentation schemes. Spearman's rank correlation coefficient was calculated between PSMA PET uptake and feature values of a Grey Level Run Length Matrix using a long and short run length emphasis (GLRLML and GLRLMS) in subregions of the parotid gland.

RESULTS

PSMA PET uptake was significantly higher (p < 0.001) in lateral/posterior regions of the glands than anterior/medial regions. Maximum uptake was found in the lateral half of parotid glands in 50 out of 60 glands. The difference in SUVmean between parotid halves is greatest when parotids are divided by a plane separating the anterior/medial and posterior/lateral halves symmetrically (out of 120 bisections tested). PSMA PET uptake was significantly correlated with CT GLRLML (p < 0.001), and anti-correlated with CT GLRLMS (p < 0.001).

CONCLUSION

Uptake of PSMA PET is heterogeneous within parotid glands, with uptake biased towards lateral/posterior regions. Uptake within parotid glands was strongly correlated with CT texture feature maps.

Giant Pleomorphic Adenoma of Submandibular Gland

Pleomorphic adenoma is a benign tumor of salivary glands which is relatively rare among head & neck neoplasms. Parotid gland is the most common site of occurrence whereas submandibular gland is rarely affected. We present a case of a giant pleomorphic adenoma of submandibular gland.

Diagnostic imaging of salivary gland cancers: REFCOR recommendations by the formal consensus method

OBJECTIVE

To define the indications for each imaging modality in the screening, characterization, extension and follow-up of salivary gland tumors.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group who drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

If a swelling of a salivary gland is palpable for 3 weeks, an ultrasound scan is recommended to confirm a tumoral lesion and rule out differential diagnoses. For a salivary gland tumor, MRI is recommended with diffusion-weighted and dynamic contrast-enhanced techniques. In the case of histologically proven malignancy or a highly suspicious lesion, a CT scan of the neck and chest is recommended to assess the tumor, lymph nodes and metastases. FDG-PET is not currently recommended in routine clinical practice for initial diagnosis, assessment of extension, evaluation of response to treatment, staging of recurrence, or follow-up of salivary gland tumors.

CONCLUSION

Assessing salivary tumors is based on MRI. Extension assessment is based on neck and chest CT.

Deep Network-Based Comprehensive Parotid Gland Tumor Detection

RATIONALE AND OBJECTIVES

Salivary gland tumors constitute 2%-6% of all head and neck tumors and are most common in the parotid gland. Magnetic resonance (MR) imaging is the most sensitive imaging modality for diagnosis. Tumor type, localization, and relationship with surrounding structures are important factors for treatment. Therefore, parotid gland tumor segmentation is important. Specialists widely use manual segmentation in diagnosis and treatment. However, considering the development of artificial intelligence-based models today, it is seen that artificial intelligence-based automatic segmentation models can be used instead of manual segmentation, which is a time-consuming technique. Therefore, we segmented parotid gland tumor (PGT) using deep learning-based architectures in the paper.

MATERIALS AND METHODS

The dataset used in the study includes 102 T1-w, 102 contrast-enhanced T1-w (T1C-w), and 102 T2-w MR images. After cropping the raw and manually segmented images by experts, we obtained the masks of these images. After standardizing the image sizes, we split these images into approximately 80% training set and 20% test set. Hereabouts, we trained six models for these images using ResNet18 and Xception-based DeepLab v3+. We prepared a user-friendly Graphical User Interface application that includes each of these models.

RESULTS

From the results, the accuracy and weighted Intersection over Union values of the ResNet18-based DeepLab v3+ architecture trained for T1C-w, which is the most successful model in the study, are equal to 0.96153 and 0.92601, respectively. Regarding the results and the literature, it can be seen that the proposed system is competitive in terms of both using MR images and training the models independently for T1-w, T1C-w, and T2-w. Expressing that PGT is usually segmented manually in the literature, we predict that our study can contribute significantly to the literature.

CONCLUSION

In this study, we prepared and presented a software application that can be easily used by users for automatic PGT segmentation. In addition to predicting the reduction of costs and workload through the study, we developed models with meaningful performance metrics according to the literature.

Pleomorphic Adenoma of the Oral Cavity: Systematic Review

Pleomorphic adenomas are the most commonly presented salivary gland tumor; however, exact etiologies are unknown. We present a systemic review investigating the demographics, clinical presentations, characteristics, and anatomical locations of oral cavity pleomorphic adenoma. Three electronic databases (PubMed, MEDLINE, and Scopus) and one search engine (Google Scholar) were used to identify studies published in English with no restrictions on the year of publication up to the first week of August 2022. Studies retrieved from the literature involved clinical presentations, characteristics, and anatomical locations of oral cavity pleomorphic adenoma, data presented as frequencies and percentages. Our systematic review included 71 studies out of 2110 identified. Pleomorphic adenoma in the oral cavity was found more commonly in females [1508 (42.9%)] than males, with an age range of 6-83 years. The most common tumor location was the palate, followed by the lips; the jaw was the least common location identified. Most cases were not characterized of having a pleomorphic adenoma [(2,918 (83%))]. The most commonly mentioned characteristic was a painless mass [(561 (16%))] and the least common characteristics were dysphagia, change in sensation, and ill-fitting prosthesis. Pleomorphic adenoma of the oral cavity can have many presentations. In any oral cavity mass, pleomorphic adenoma should be included in the differential diagnosis and a complete surgical excision preferred treatment.

ACR Appropriateness Criteria® Staging and Post-Therapy Assessment of Head and Neck Cancer

Imaging of head and neck cancer at initial staging and as part of post-treatment surveillance is a key component of patient care as it guides treatment strategy and aids determination of prognosis. Head and neck cancer includes a heterogenous group of malignancies encompassing several anatomic sites and histologies, with squamous cell carcinoma the most common. Together this comprises the seventh most common cancer worldwide. At initial staging comprehensive imaging delineating the anatomic extent of the primary site, while also assessing the nodal involvement of the neck is necessary. The treatment of head and neck cancer often includes a combination of surgery, radiation, and chemotherapy. Post-treatment imaging is tailored for the evaluation of treatment response and early detection of local, locoregional, and distant recurrent tumor. Cross-sectional imaging with CT or MRI is recommended for the detailed anatomic delineation of the primary site. PET/CT provides complementary metabolic information and can map systemic involvement. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Sialography: a pictorial review

Non-tumour inflammatory and obstructive salivary gland pathologies such as sialadenitis, sialolithiasis, sialadenosis, ductal strictures, etc. require precise radiological evaluation and mapping of salivary gland ductal system for better treatment outcome. Conventional sialography is considered as a useful and reliable technique in evaluation of salivary glands especially intrinsic and acquired abnormalities involving the ductal system and is useful for detection of non-radiopaque sialoliths which are invisible on routine plain radiographs. Primarily sialography is used as a diagnostic tool, additionally it plays an important therapeutic role as salivary gland lavage in cases of recurrent salivary gland infections and in obstructive salivary gland disorders by helping in clearance of mucous plugs or small sialoliths within the ducts. Recently, diagnostic performance of computed tomography (CT) sialography is being explored and has been reported to have high sensitivity in detection of small sialoliths and allows differentiation of sialoliths from other calcifications in glandular ductal system. Multiplanar three dimensional (3D) reconstructed CT images have been reported to play a key role in determination of anatomical location or extent of salivary gland disease without superimposition or distortion of structures. This review aims to discuss the disease specific applications of sialography and CT Sialography in particular for visualization of salivary gland disorders.

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

BACKGROUND

The purpose of this study was to investigate how the systemic inflammation response index (SIRI), systemic immune-inflammation index (SII), neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR), and radiomic metrics (quantitative descriptors of image content) extracted from MRI sequences by machine learning increase the efficacy of proper presurgical differentiation between benign and malignant salivary gland tumors.

METHODS

A retrospective study of 117 patients with salivary gland tumors was conducted between January 2015 and November 2022. Univariate analyses with nonparametric tests and multivariate analyses with machine learning approaches were used.

RESULTS

Inflammatory biomarkers showed statistically significant differences (p < 0.05) in the Kruskal-Wallis test based on median values in discriminating Warthin tumors from pleomorphic adenoma and malignancies. The accuracy of NLR, PLR, SII, and SIRI was 0.88, 0.74, 0.76, and 0.83, respectively. Analysis of radiomic metrics to discriminate Warthin tumors from pleomorphic adenoma and malignancies showed statistically significant differences (p < 0.05) in nine radiomic features. The best multivariate analysis result was obtained from an SVM model with 86% accuracy, 68% sensitivity, and 91% specificity for six features.

CONCLUSIONS

Inflammatory biomarkers and radiomic features can comparably support a pre-surgical differential diagnosis.

Clinico-histopathological review of 255 patients who underwent parotidectomy for pleomorphic adenoma: a 10-year retrospective study-a proposal for an optimal diagnostic and therapeutic algorithm for patients with recurrent pleomorphic adenoma

PURPOSE

Pleomorphic adenoma (mixed tumor) is the most common neoplasm of the parotid gland and one of the most frequent types of salivary gland tumor, generally with benign behavior and relatively slow growing. The adenomas could arise from the superficial, deep or from both superficial and deep parotid's lobes.

METHODS

The aim of this review is to retrospectively analyze the surgical management of patients with pleomorphic adenoma of the parotid gland performed at the Department of Otorhinolaryngology (Department of Sense Organs of "Azienda Policlinico Umberto I" in Rome), from 2010 to 2020, with a focus on the percentage of recurrence and on the complication related to surgery to suggest an optimal diagnostic and therapeutic algorithm for patients with recurrent pleomorphic adenoma. The analysis of the complications observed in case of different surgical approaches was performed using the X² test.

RESULTS

The choice of a surgical approach (superficial parotidectomy-SP, total parotidectomy-TP, extracapsular dissection-ECD) depends on several elements, such as the location and the size of the adenoma, the availability of existing technical facilities and the professional experience of the surgeon. A transient facial palsy was present in 37.6%, 2.7% reported a permanent facial nerve palsy, 1.6% developed a salivary fistula, 1.6% a post-operative bleeding and 2.3% showed Frey Syndrome.

CONCLUSION

The surgical management of this benign lesion is required, even in asymptomatic cases, to prevent the progressive growing and to reduce the risk of malignant transformation. The goal of surgical excision is to obtain the complete resection to minimize the risk of tumor recurrence and avoiding facial nerve disability. Therefore, an accurate preoperative study of the lesion and the choice of the most appropriate surgical treatment are essential to minimize the rate of recurrence.

Magnetic resonance imaging of parotid gland tumors: a pictorial essay

Imaging of parotid gland tumors is challenging due to the wide variety of differential diagnoses. Malignant parotid tumors can have very similar features to benign ones, such as slow growth and displacement instead of infiltration of neighboring structures. Malignant and benign tumors may therefore not be clinically distinguishable. Correct characterization of parotid tumors (i.e., benign or malignant) determines preoperative treatment planning and is important in optimizing the individualized surgical plan. Magnetic resonance imaging (MRI) is the imaging modality of choice for evaluation of suspected parotid gland lesions and differentiation between benign and malignant lesions. Certain conventional MRI features can suggest whether a mass is more likely to be a benign or low-grade malignancy or a high-grade malignancy and adding diffusion-weighted imaging or advanced MRI techniques like perfusion can aid in this distinction. Morphological features seen on MRI, such as low signal on T2-w, infiltrative changes or ill-defined margins, change over time and diffusion restriction can point to the malignant nature of the lesion. MRI is useful for detection and localization of the lesion(s), and associated findings like perineural spread of tumor, lymph node involvement and infiltrative changes of the surrounding tissues. In this pictorial essay, we present selected images of a variety of benign and malignant parotid tumors and emphasize the MRI features that may be useful in their characterization.

Current opinions on diagnosis and treatment of adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare malignant tumor derived mainly from the salivary glands, representing approximately 1% of all headandneck carcinomasand 10% of all salivary gland neoplasms. ACC displays a paradoxical behavioral combination of an indolent growth pattern but an aggressive progression, with local recurrence and distant metastasis. The propensity of ACC of the head and neck (ACCHN) for perineural invasion and its anatomical location, especially if it extends to the nasal cavity and paranasal sinuses, facilitates tumor involvement in the surrounding structures, such as the orbit, pterygopalatine fossa, Meckel'scave, and cavernous sinus, which can lead to skull base involvement and intracranial extension. Despite advances in molecular mechanisms and diagnostic imaging, ACC treatment remainschallenging due to the lack ofconsensuson treatment patterns. In this review, we aimed toprovideanupdatedinsight intothe understanding of ACCHN by focusing on clinical behavior, imaging diagnosis, pathological features, and therapeutic strategies. We reviewed the molecular mechanisms, especially in ACCHN with perineural invasion, and elaborated on treatment options, including chemotherapy, targeted therapies, and immunotherapy, to establish a comprehensive understanding of ACC to arrive at a policy for proper diagnosis, preoperative evaluation, and therapeutic strategies.

Parotid gland incidentalomas: A single-institution experience

PURPOSE

Parotid gland incidentaloma (PGI) management has not been well characterized in the literature. This study assesses clinicopathologic features, initial evaluation, management, and outcomes of PGIs discovered on various imaging modalities.

MATERIALS AND METHODS

This is a retrospective case series from a single academic institution. The study cohort included 34 patients with parotid gland incidentalomas discovered between January 2009 and December 2019.

RESULTS

Parotid gland incidentalomas were most frequently identified on magnetic resonance imaging (16 patients, 47.1%). Most patients (26 patients, 76.5%) underwent further evaluation with subsequent imaging, most often magnetic resonance imaging (18 patients, 69.2%), and fine needle aspiration biopsy (33 patients, 97.1%). Most tumors were benign on fine needle aspiration biopsy (19 patients, 57.6%). Most cases (21 patients, 61.8%) were managed with observation without parotidectomy. Malignant findings on fine needle aspiration cytology were associated with increased likelihood of undergoing parotidectomy (25% vs 0%; p = 0.04). Among the patients who received a parotidectomy, most (8 patients, 61.5%) had benign findings on final histopathology.

CONCLUSION

Parotid gland incidentalomas were discovered across a diverse set of imaging modalities in our institution. Magnetic resonance imaging and fine needle aspiration were often performed for further evaluation. Most cases were found to be benign on fine needle aspiration and were managed with observation. These findings highlight the necessity of appropriate work-up for these tumors, and the need for shared decision making between the patient and the physician in selecting the appropriate treatment strategy.

Surgical Treatment of a Giant Pleomorphic Adenoma of the Submandibular Gland: A Case Report

Pleomorphic adenomas (PAs) are the most common benign salivary neoplasms. PAs are generally slow-growing but may sometimes become aggressive and grow rapidly within a short period of time. Here, we report the case of an 83-year-old Chinese woman with an anterior neck mass that had been growing over the past 30 years. She felt uncomfortable because the mass had grown quite rapidly in the past year. The final diagnosis of a PA of the left submandibular gland was confirmed by histopathological and immunohistochemical examinations after surgical resection. Our patient recalled a history of an excision of a neck mass 40 years prior to presentation at another hospital. Based on our imaging findings and surgical findings, we speculate that the neck mass 40 years prior may also have been a PA. Our case reminds us the rare recurrence possibility of PAs, and early and thorough resection may have a good prognosis. In addition, to the best of our knowledge, this is the largest PA of the submandibular gland reported to date.

Multifrequency magnetic resonance elastography-based tomoelastography of the parotid glands-feasibility and reference values

OBJECTIVES

Accurate radiological differentiation of parotid tumors remains challenging despite recent technical advances in quantitative medical imaging. Multifrequency magnetic resonance elastography (MRE) could provide additional information on viscoelastic properties of normal and abnormal biological tissues. This study investigates the feasibility of MRE of the parotid glands in healthy participants and provides first reference values.

METHODS

20 healthy participants underwent multifrequency MRE of both parotid glands at 3 Tesla. Shear waves at frequencies of 25, 30, 40, and 50 Hz were introduced into the participants' heads through the occiput using pressurized-air actuators. Shear wave speed (SWS) and loss angle of the shear modulus (φ) were reconstructed by tomoelastography post-processing as surrogate parameters for tissue stiffness and viscosity or fluidity. 10 participants underwent repeated MRE to determine test-retest reliability based on intraclass correlation coefficients.

RESULTS

All MRE datasets acquired could be included in the analysis. Mean SWS was 0.97 ± 0.13 m/s, and mean φ was 0.59 ± 0.05 rad, each for both sides combined and without notable lateral difference (p = 0.88/0.87). Test-retest reliability was good for SWS (ICC = 0.84 for both sides/ICC = 0.77 for the right side/ICC = 0.79 for the left side) and good to excellent for φ(ICC = 0.94/0.86/0.90).

CONCLUSIONS

Multifrequency MRE of the parotid glands is feasible and reliable. This technique, therefore, is a promising method for investigating the viscoelastic properties of salivary gland tumors in future studies.

Fine-Needle Aspiration Cytology of Salivary Gland Tumors Before the Milan System: Ten Years of Experience at a Tertiary Care Center in Turkey

Objective

The role of fine-needle aspiration cytology (FNAC) is well established for preoperative evaluation of patients with salivary gland lesions. However, the lack of a uniform system for salivary gland FNAC has limited its effectiveness. In recent years, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has been in use around the world to report the cytology results. We aimed to investigate the efficacy and accuracy of FNAC examined according to pre-MSRSGC era dichotomous benign/malignant classification in salivary gland tumors.

Methods

Patients who underwent surgery between January 2011 and December 2020 due to major salivary gland tumors were retrospectively analyzed. Two hundred and four patients were included in the analysis. Preoperative FNAC results and final histopatological diagnoses were grouped as benign or malignant. Final histopatological diagnoses were compared with the preoperative FNAC results. Also, sensitivity, specificity, and accuracy of the preoperative FNAC results, as well as the agreement between both tests were investigated.

Results

The sensitivity, specificity, accuracy, positive and negative predictive values of the preoperative FNAC for the diagnosis of malignancy were 59.09%, 97.85%, 93.75%, 76.47%, and 95.29%, respectively. There was a moderate agreement between the preoperative FNAC results and final histopatological diagnoses.

Conclusion

The accuracy of the preoperative FNAC and the information given about malignancy risk are the most important criteria for patient management and decision-making. The MSRSGC, which consists of a six-tiered classification rather than a dichotomous "yes/no" system, may contribute to patient management and decision-making by increasing the efficacy and accuracy of FNAC.

Bilateral Submandibular Gland Aplasia: An Unusual Cause of Sublingual Swelling—The Role of Imaging in Patient Management

There are very limited reports of aplasia of bilateral submandibular glands. We report the case of a 55-year-old male who presented with nontender palpable sublingual masses. On computed tomography and magnetic resonance imaging, bilateral submandibular gland aplasia and compensatory hypertrophy of bilateral parotid and sublingual glands were seen with herniation of hypertrophied sublingual glands through the bilateral mylohyoid muscles presenting as palpable sublingual region masses. Additional finding of bilateral accessory parotid glands was also noted. Prolapsed hypertrophied sublingual glands should be considered in patients presenting with bilateral sublingual masses to avoid unnecessary invasive procedures. We suggest radiological evaluation of such cases prior to any intervention.

Breast Cancer Metastasis to the Parotid: A Case Report with Imaging Findings

Patient: Female, 59-year-old

Final Diagnosis: Breast cancer metastasis to the parotid

Symptoms: Growing mass in the parotid gland

Medication:—

Clinical Procedure: —

Specialty: Radiology

An Overview on the Histogenesis and Morphogenesis of Salivary Gland Neoplasms and Evolving Diagnostic Approaches

Simple Summary

Diagnosing salivary gland neoplasms (SGN) remain a challenge, given their underlying biological nature and overlapping features. Evolving techniques in molecular pathology have uncovered genetic mutations resulting in these tumors. This review delves into the molecular etiopatho-genesis of SGN, highlighting advanced diagnostic protocols that may facilitate the identification and therapy of a variety of SGN.

Abstract

Salivary gland neoplasms (SGN) remain a diagnostic dilemma due to their heterogenic complex behavior. Their diverse histomorphological appearance is attributed to the underlying cellular mechanisms and differentiation into various histopathological subtypes with overlapping fea-tures. Diagnostic tools such as fine needle aspiration biopsy, computerized tomography, magnetic resonance imaging, and positron emission tomography help evaluate the structure and assess the staging of SGN. Advances in molecular pathology have uncovered genetic patterns and oncogenes by immunohistochemistry, fluorescent in situ hybridization, and next–generation sequencing, that may potentially contribute to innovating diagnostic approaches in identifying various SGN. Surgical resection is the principal treatment for most SGN. Other modalities such as radiotherapy, chemotherapy, targeted therapy (agents like tyrosine kinase inhibitors, monoclonal antibodies, and proteasome inhibitors), and potential hormone therapy may be applied, depending on the clinical behaviors, histopathologic grading, tumor stage and location, and the extent of tissue invasion. This review delves into the molecular pathways of salivary gland tumorigenesis, highlighting recent diagnostic protocols that may facilitate the identification and management of SGN.

Diagnostic Utility of Radiomics in Thyroid and Head and Neck Cancers

Radiomics is an emerging field in radiology that utilizes advanced statistical data characterizing algorithms to evaluate medical imaging and objectively quantify characteristics of a given disease. Due to morphologic heterogeneity and genetic variation intrinsic to neoplasms, radiomics have the potential to provide a unique insight into the underlying tumor and tumor microenvironment. Radiomics has been gaining popularity due to potential applications in disease quantification, predictive modeling, treatment planning, and response assessment - paving way for the advancement of personalized medicine. However, producing a reliable radiomic model requires careful evaluation and construction to be translated into clinical practices that have varying software and/or medical equipment. We aim to review the diagnostic utility of radiomics in otorhinolaryngology, including both cancers of the head and neck as well as the thyroid.

Sialendoscopy: A Four-Year Single Center Experience

PURPOSE

Sialendoscopy is a relatively new technique designed to diagnose and treat benign obstructive salivary gland disease using a minimally invasive approach. The purpose of this study is to present our experiences regarding the use of sialendoscopy in the form of a 4-year, single center experience and to demonstrate its usefulness in oral and maxillofacial practice.

METHODS

We collected data on patients who underwent sialendoscopy at the Oral-Maxillofacial Surgery Department of UZ Leuven between November 2015 and August 2019, including age, gender, sex, initial clinical presentation and symptoms, gland involvement, type of diagnostic investigations, diagnosis, localization of the obstruction, therapeutic intervention, surgeon, type of anesthesia, materials used, complications, secondary treatment, duration of follow-up, and outcome. Statistical analyses were performed, chi-squared was used to compare the different variables with P < .05 being considered significant.

RESULTS

During the 4-year timeframe, a total of 44 patients (31 female, 13 male) underwent sialendoscopy in a total of 47 procedures. The average age at time of sialendoscopy was 47.4 years. The most frequent cause of obstruction was sialolithiasis (70%). Cone-beam computed tomography (CBCT) was the most accurate preoperative investigation for the diagnosis of lithiasis (57%). Symptom improvement occurred in 57.9% of patients, with a complication rate of 11%. None of the complications were permanent.

CONCLUSION

Sialendoscopy can be considered safe and effective for both the diagnosis and treatment of benign obstructive salivary gland disease, with a useful place in oral and maxillofacial surgical practice. We recommend the inclusion of CBCT and/or ultrasound in the diagnostic workup prior to endoscopy.

Salivary gland carcinoma in children and adolescents: The EXPeRT/PARTNER diagnosis and treatment recommendations

Salivary gland carcinomas (SGCs) are rare during childhood and adolescence. Consequently, no standardized recommendations for the diagnosis and therapeutic management of pediatric SGC are available, and pediatric oncologists and surgeons generally follow adult guidelines. Complete surgical resection with adequate margins constitutes the cornerstone of treatment. However, the indications and modalities of adjuvant therapy remain controversial and may be challenging in view of the potential long-term toxicities in the pediatric population. This paper presents the consensus recommendations for the diagnosis and treatment of children and adolescents with SGCs, established by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the EU-funded PARTNER project (Paediatric Rare Tumours Network - European Registry).

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.

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.

Second Malignancies after Radiation Therapy: Update on Pathogenesis and Cross-sectional Imaging Findings

A wide spectrum of second cancers occur as late complications of radiation therapy (RT) used to treat various malignancies. In addition to the type and dose of radiation, lifestyle, environmental, and genetic factors are important to the development of second malignancies in cancer survivors. Typically, RT-induced malignancies (RTIMs) are biologically aggressive cancers with a variable period of 5-10 years for hematologic malignancies and 10-60 years for solid tumors between RT and the development of the second cancer. Although carcinomas and leukemias commonly develop after low-dose RT, sarcomas occur in tissues or organs that receive high-dose RT. Angiosarcomas and unclassified pleomorphic sarcomas are the two most common RT-associated sarcomas; other sarcomas include malignant peripheral nerve sheath tumors, leiomyosarcomas, osteosarcomas, chondrosarcomas, and dedifferentiated or pleomorphic liposarcomas. Select RTIMs show tumor genetic characteristics that allow accurate diagnosis. Nearly all cutaneous angiosarcomas after RT for breast cancer and 90% of RT-associated malignant peripheral nerve sheath tumors are characterized by MYC gene amplifications and loss of H3 K27me3 expression, respectively. Classic papillary thyroid carcinomas that develop after RT frequently harbor RET/PTC rearrangements and have a favorable prognosis, despite their advanced stage at patient presentation. Select RTIMs demonstrate characteristic imaging findings and typically develop in the prior radiation field. Imaging is essential to early diagnosis, characterization, localization, and staging of RTIMs. Familiarity of radiologists with the diverse spectrum of RTIMs is essential for early diagnosis and optimal management. An invited commentary by Shapiro is available online. ^©RSNA, 2021.

Management of a Buccal Space Mass: A Clinical Case Report

Background

Buccal space tumors constitute rare pathologies with significant histological diversity. They may pose serious diagnostic and therapeutic challenges for the head and neck surgeon.

Methods

A case of buccal space tumor diagnosed and treated in a tertiary center is presented. Clinical presentation, imaging, and surgical approach are discussed, followed by review of the literature.

Results

A 79-year-old male patient with a slowly growing painless mass on the right cheek presented to a head and neck reference center. Imaging revealed a tumor of the right buccal space with nonspecific characteristics. Imaging studies revealed extended infiltration of the masseter muscle as well as the anterior border of the parotid gland. FNA biopsy was performed but was nondiagnostic. The decision of surgical excision with a modified parotidectomy incision was taken. The lesion was completely excised with preservation of neighboring facial nerve branches and ipsilateral Stensen's duct. The postoperative course was uneventful. Histological examination showed CLL/Lymphoma, and the patient was referred to the hematology department for staging and further management.

Conclusion

Differential diagnosis of buccal space masses is very diverse. Despite challenges in the diagnostic and therapeutic approach, these entities may be managed surgically with minimal morbidity.

Can Magnetic Resonance Radiomics Analysis Discriminate Parotid Gland Tumors? A Pilot Study

Our purpose is to evaluate the performance of magnetic resonance (MR) radiomics analysis for differentiating between malignant and benign parotid neoplasms and, among the latter, between pleomorphic adenomas and Warthin tumors. We retrospectively evaluated 75 T2-weighted images of parotid gland lesions, of which 61 were benign tumors (32 pleomorphic adenomas, 23 Warthin tumors and 6 oncocytomas) and 14 were malignant tumors. A receiver operating characteristics (ROC) curve analysis was performed to find the threshold values for the most discriminative features and determine their sensitivity, specificity and area under the ROC curve (AUROC). The most discriminative features were used to train a support vector machine classifier. The best classification performance was obtained by comparing a pleomorphic adenoma with a Warthin tumor (yielding sensitivity, specificity and a diagnostic accuracy as high as 0.8695, 0.9062 and 0.8909, respectively) and a pleomorphic adenoma with malignant tumors (sensitivity, specificity and a diagnostic accuracy of 0.6666, 0.8709 and 0.8043, respectively). Radiomics analysis of parotid tumors on conventional T2-weighted MR images allows the discrimination of pleomorphic adenomas from Warthin tumors and malignant tumors with a high sensitivity, specificity and diagnostic accuracy.

Diagnostic value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in sublingual and submandibular salivary gland tumors

The aim of the present study was to compare the diagnostic accuracy of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) with that of conventional imaging studies (CIS), such as CT or magnetic resonance imaging (MRI), in the clinical diagnosis and staging of submandibular and sublingual salivary gland tumors. In addition, the data obtained were used to evaluate the significance of maximum standardized uptake value (SUVmax) in diagnosing benign or malignant lesions. For the present study, 18 patients with submandibular or sublingual neoplasms underwent F-18 FDG PET/CT imaging with accompanying CT or MRI. The diagnostic values from 43 F-18 FDG PET/CT scans and 28 CIS of the 18 patients were compared to the gold standard histopathological and/or cytopathological diagnosis. The results demonstrated that the diagnostic accuracy for predicting primary tumors was similar between F-18 FDG PET/CT and CIS. By contrast, PET/CT imaging was more accurate in detecting lymph node metastasis compared with CT or MRI (95.4 vs. 66.7%). F-18 FDG PET/CT had a sensitivity of 88.9% and a specificity of 97.1%, whereas CT or MRI had a sensitivity of 54.5% and a specificity of 75.0%. F-18 FDG PET/CT also enabled screening for distant metastasis, as observed in 10 cases in the present study. Furthermore, there were no significant differences in SUVmax between benign or malignant salivary gland lesions, as high glucose metabolism was also observed in benign tumors. In conclusion, F-18 FDG PET/CT provides more accurate diagnostic information for the evaluation of submandibular and sublingual salivary gland tumors as compared with CIS in terms of lymph node and distant metastasis.

The effect of antiretroviral therapy on fine-needle aspiration of salivary gland masses in HIV-infected patients

BACKGROUND

South Africa has a very high prevalence of HIV/AIDS. Salivary gland lesions are common in HIV-infected patients. The aim of this study was to determine the pathologic entities diagnosed on fine-needle aspiration (FNA) of salivary gland masses in an HIV-infected study population that now has free access to antiretroviral (ARV) therapy and how this differs from the pathologic entities before the advent of widespread ARV availability, and if the Milan system for reporting salivary gland cytopathology (MSRSGC) can be applied to HIV-infected patients.

METHODS

A retrospective review was performed on confirmed HIV-infected patients who underwent FNA of salivary gland masses over a two-year period.

RESULTS

A total of 360 patients underwent FNA of salivary gland masses within the designated time frame, 58.3% (210) females and 41.7% (150) males. Patient ages ranged from 7 months to 67 years with a mean age of 36.9 years. The parotid gland was the most biopsied salivary gland at 55.3% (199). The most common diagnosis made in patients on antiviral therapy was lymphoepithelial cyst while that in patients not on antiviral therapy was infectious (including abscess and mycobacterial infection). The most frequent neoplasms were non-Hodgkin lymphoma, pleomorphic adenoma and squamous-cell carcinoma.

CONCLUSION

Patients on ARV therapy had higher CD4 counts, fewer infectious lesions, and more reactive and benign salivary gland lesions. Patients not on treatment had significantly lower CD4 counts and were frequently diagnosed with infectious processes. The MSRSGC is well-suited for use in HIV-infected patients.

MRI-based texture analysis to differentiate the most common parotid tumours

AIM

To evaluate magnetic resonance imaging (MRI) features and signal characteristics of parotid masses and investigate the added role of texture analysis (TA) in the differentiation of parotid tumours.

MATERIALS AND METHODS

Ninety-five patients (42 women, 53 men; mean age 51.67±14.15) were included in this study. The study group consisted of 40 pleomorphic adenoma, 45 Warthin's tumour, and 10 mucoepidermoid carcinomas. Two reviewers assessed the MRI sequences retrospectively. Fat-suppressed T2-weighted and contrast-enhanced T1-weighted axial images were used for TA. Receiver operating characteristic curve analyses were performed to evaluate the ability to make a diagnosis. Logistic regression analyses were conducted to explore the independent risk factors among the MRI features and to analyse the added value of TA to the qualitative analysis.

RESULTS

Significant differences were found in the tumour border (p<0.001), infiltration of the surrounding tissue (p=0.003), contrast-enhancement grading (p<0.001), perineural spread (p=0.013), and pathological lymph nodes (p<0.001) between the malignant and benign tumours. Kurtosis on contrast-enhanced T1-weighted images, and skewness and kurtosis on T2-weighted images were significantly different between the three groups (p=0.020, <0.001, 0.003; respectively). A kurtosis value on T2-weighted images <2.815 along with an ill-defined border had the highest specificity (98.8%) and positive predictive value (83.3%) in the differentiation of malignant tumours.

CONCLUSION

The addition of TA parameters to the MRI findings may contribute to distinguish benign from malignant parotid tumours.

Differentiation of salivary gland tumors through tumor heterogeneity: a comparison between pleomorphic adenoma and Warthin tumor using CT texture analysis

PURPOSE

We compared the diagnostic performance of CT texture analysis in single-phase CT scan with that of conventional enhancement pattern analysis in a two-phase CT scan for discrimination of salivary gland tumors, Warthin tumor (WT) from pleomorphic adenoma (PA).

METHODS

One hundred seventy-eight patients with PA and 84 patients with WT were selected and CT texture analysis was separately performed on early (40s) and delayed (180s) phases, after injection of the contrast agent, using commercially available software. The attenuation changes and enhancement patterns were visually and quantitatively assessed with Hounsfield units (HU). Differences between PAs and WTs were analyzed using χ² test and independent t test. Diagnostic performance of texture parameters in single-phase CT was compared with that of dynamic enhancement pattern in two-phase CT using the McNemar test.

RESULTS

Ratio of tumoral HU (delayed phase/early phase) was significantly higher in PAs compared with WTs (p < 0.001). Tumor heterogeneity parameters, standard deviation (SD) and entropy, were significantly lower in WTs regardless of the type of filter used (p ≤ 0.001). Mean with coarse filter (AUC = 0.944) on early phase scan and entropy with medium filter (AUC = 0.901) on delayed scan were best discriminators between PAs and WTs. Diagnostic accuracy of mean (90.5%) on early scan and entropy (84.7%) on delayed scan was not significantly different from the accuracy (89.3%) of conventional wash-out pattern for distinguishing WTs from PAs (p = 0.742, p = 0.088, respectively).

CONCLUSION

Diagnostic performance of texture parameters was similar to that of quantitative enhancement pattern for differentiating WTs from PAs, with the advantage in lower radiation exposure.

Diagnostic Value of Superb Microvascular Imaging in Parotid Tumors

Background

The aim of this study was to evaluate the clinical diagnostic value of superb microvascular imaging (SMI) in assessing vascular distribution, vascularity, and vessel morphology of parotid tumors (PTs).

Material/Methods

PT patients confirmed by postoperative histopathological detection and who underwent color Doppler flow imaging (CDFI), microvascular imaging (MVI), and SMI examination were recruited. PTs were classified into 3 groups: pleomorphic adenoma (PA), Warthin tumor (WT), and malignant PT (MT). The tumor vascular distribution, vascularity, and vessel morphology recorded by CDFI, MVI, and SMI were compared among PA, WT, and MT group. PT diagnosis was performed using histopathological detection. Fisher’s exact test was used to compare the diagnostic sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy between SMI and MVI examination in PTs.

Results

We enrolled 198 PTs consisting of 114 PAs, 56 WTs, and 28 MTs into our study. CDFI examination found no significant differences in vascular distribution and vascularity among the PA, WT, and WT groups. SMI examination found significant differences in vascular distribution and vascularity among the 3 groups. MVI found significant differences in vessel morphology, including uneven distribution of blood flow, arborization, and irregular blood flow among the PA, WT, and MT groups. SMI found significant differences in arborization and irregular blood flow, but none of the differences in uneven distribution of blood flow among the 3 groups were significant. The diagnostic sensitivity, specificity, and accuracy of SMI and MVI in PTs showed no significant differences.

Conclusions

SMI more accurately evaluated the vascular distribution and vascularity of PTs than CDFI. SMI might be a potential non-invasive diagnostic method for PTs in clinical practice.

The role of diffusion-weighted and dynamic contrast enhancement perfusion-weighted imaging in the evaluation of salivary glands neoplasms

OBJECTIVES

To evaluate the association of magnetic resonance diffusion-weighted imaging (DwI) and dynamic contrast-enhanced perfusion-weighted imaging (DCE-PwI) with a temporal resolution of 5 s, wash-in < 120 s, and wash-out ratio > 30% in the evaluation of salivary glands neoplasms.

METHODS

DwI and DCE-PwI of 92 salivary glands neoplasms were assessed. The apparent diffusion coefficient (ADC) was calculated by drawing three regions of interest with an average area of 0.30-0.40 cm² on three contiguous axial sections. The time/intensity curve was generated from DCE-PwI images by drawing a region of interest that included at least 50% of the largest lesion section. Vessels, calcifications, and necrotic/haemorrhagic or cystic areas within solid components were excluded. The association of ADC ≥ 1.4 × 10^-3 mm²/s with type A curves (progressive wash-in) and ADC 0.9-1.4 × 10^-3 mm²/s with type C curves (rapid wash-in/slow wash-out) were tested as parameters of benignity and malignancy, respectively. Type B curve (rapid wash-in/rapid wash-out) was not used as a reference parameter.

RESULTS

ADC ≥ 1.4 × 10^-3 mm²/s and type A curves were observed only in benign neoplasms. ADC of 0.9-1.4 × 10^-3 mm²/s and type C curves association showed specificity of 94.9% and positive predictive value of 81.8% for epithelial malignancies. The association of ADC < 0.9 × 10^-3 mm²/s with type B and C curves showed diagnostic accuracy of 94.6% and 100% for Warthin tumour and lymphoma, respectively.

CONCLUSIONS

ADC ≥ 1.4 × 10^-3 mm²/s and type A curves association was indicative of benignity. Lymphomas exhibited ADC < 0.7 × 10^-3 mm²/s and type C curves. The association of ADC < 0.9 × 10^-3 mm²/s and type B and C curves had accuracy 94.6% and 88.5% for Warthin tumour and epithelial malignancies, respectively.