Salivary gland tumors: evaluation with two-phase helical CT

Discriminating atypical parotid carcinoma and pleomorphic adenoma utilizing extracellular volume fraction and arterial enhancement fraction derived from contrast-enhanced CT imaging: A multicenter study

OBJECTIVES

To investigate the added value of extracellular volume fraction (ECV) and arterial enhancement fraction (AEF) derived from enhanced CT to conventional image and clinical features for differentiating between pleomorphic adenoma (PA) and atypical parotid adenocarcinoma (PCA) pre-operation.

METHODS

From January 2010 to October 2023, a total of 187 cases of parotid tumors were recruited, and divided into training cohort (102 PAs and 51 PCAs) and testing cohort (24 PAs and 10 atypical PCAs). Clinical and CT image features of tumor were assessed. Both enhanced CT-derived ECV and AEF were calculated. Univariate analysis identified variables with statistically significant differences between the two subgroups in the training cohort. Multivariate logistic regression analysis with the forward variable selection method was used to build four models (clinical model, clinical model+ECV, clinical model+AEF, and combined model). Diagnostic performances were evaluated using receiver operating characteristic (ROC) curve analyses. Delong's test compared model differences, and calibration curve and decision curve analysis (DCA) assessed calibration and clinical application.

RESULTS

Age and boundary were chosen to build clinical model, and to construct its ROC curve. Amalgamating the clinical model, ECV, and AEF to establish a combined model demonstrated superior diagnostic effectiveness compared to the clinical model in both the training and test cohorts (AUC = 0.888, 0.867). There was a significant statistical difference between the combined model and the clinical model in the training cohort (p = 0.0145).

CONCLUSIONS

ECV and AEF are helpful in differentiating PA and atypical PCA, and integrating clinical and CT image features can further improve the diagnostic performance.

Use of Computed Tomography-Based Texture Analysis to Differentiate Benign From Malignant Salivary Gland Lesions

OBJECTIVE

Salivary gland lesions show overlapping morphological findings and types of time/intensity curves. This research aimed to evaluate the role of 2-phase multislice spiral computed tomography (MSCT) texture analysis in differentiating between benign and malignant salivary gland lesions.

METHODS

In this prospective study, MSCT was carried out on 90 patients. Each lesion was segmented on axial computed tomography (CT) images manually, and 33 texture features and morphological CT features were assessed. Logistic regression analysis was used to confirm predictors of malignancy ( P < 0.05 was considered to be statistically significant), followed by receiver operating characteristics analysis to assess the diagnostic performance.

RESULTS

Univariate logistic regression analysis revealed that morphological CT features (shape, size, and invasion of adjacent tissues) and 17 CT texture parameters had significant differences between benign and malignant lesions ( P < 0.05). Multivariate binary logistic regression demonstrated that shape, invasion of adjacent tissues, entropy, and inverse difference moment were independent factors for malignant tumors. The diagnostic accuracy values of multivariate binary logistic models based on morphological parameters, CT texture features, and a combination of both were 87.8%, 90%, and 93.3%, respectively.

CONCLUSIONS

Two-phase MSCT texture analysis was conducive to differentiating between malignant and benign neoplasms in the salivary gland, especially when combined with morphological CT features.

Deep learning-assisted diagnosis of parotid gland tumors by using contrast-enhanced CT imaging

OBJECTIVES

Imaging interpretation of the benignancy or malignancy of parotid gland tumors (PGTs) is a critical consideration prior to surgery in view of therapeutic and prognostic values of such discrimination. This study investigates the application of a deep learning-based method for preoperative stratification of PGTs.

MATERIALS AND METHODS

Using the 3D DenseNet-121 architecture and a dataset consisting of 117 volumetric arterial-phase contrast-enhanced CT scans, we developed a binary classifier for PGT distinction and tested it. We compared the discriminative performance of the model on the test set to that of 12 junior and 12 senior head and neck clinicians. Besides, potential clinical utility of the model was evaluated by measuring changes in unassisted and model-assisted performance of junior clinicians.

RESULTS

The model finally reached the sensitivity, specificity, PPV, NPV, F1-score of 0.955 (95% CI 0.751-0.998), 0.667 (95% CI 0.241-0.940), 0.913 (95% CI 0.705-0.985), 0.800 (95% CI 0.299-0.989) and 0.933, respectively, comparable to that of practicing clinicians. Furthermore, there were statistically significant increases in junior clinicians' specificity, PPV, NPV and F1-score in differentiating benign from malignant PGTs when unassisted and model-assisted performance of junior clinicians were compared.

CONCLUSION

Our results provide evidence that deep learning-based method may offer assistance for PGT's binary distinction.

Enhanced CT combined with texture analysis for differential diagnosis of pleomorphic adenoma and adenolymphoma

OBJECTIVE

This study sought to evaluate the worth of the general characteristics of enhanced CT images and the histogram parameters of each stage in distinguishing pleomorphic adenoma (PA) and adenolymphoma (AL).

METHODS

The imaging features and histogram parameters of preoperative enhanced CT images in 20 patients with PA and 29 patients with AL were analyzed. Tumor morphology and histogram parameters of PA and AL were compared. Area under the curve (AUC), sensitivity, and subject operational feature specificity (ROC) analysis were used to determine the differential diagnostic effect of single-stage or multi-stage parameter combinations.

RESULTS

The difference in CT value and net enhancement value of arterial phase (AP) were significant (p < 0.05); Flat sweep phase (FSP), AP mean, percentiles, 10th, 50th, 90th, 99th and arterial period variance and venous phase (VP) kurtosis in the nine histogram parameters of each period (p < 0.05). An analysis of the ROC curve revealed a maximum area beneath the curve (AUC) in the 90th percentile of FSP for a single-parameter differential diagnosis to be 0.870. The diagnostic efficacy of the mean value of FSP + The 90th percentile of AP + Kurtosis of VP was the best in multi-parameter combination diagnosis, with an AUC of 0.925, and the sensitivity and specificity of 0.900 and 0.850, respectively.

CONCLUSION

The histogram analysis of enhanced CT images is valuable for the differentiation of PA and AL. Moreover, the combination of single-stage parameters or multi-stage parameters can improve the differential diagnosis efficiency.

Oncocytic carcinoma of the parotid gland as a manifestation of Birt-Hogg-Dube syndrome

Renal oncocytomas are commonly reported in association with Birt-Hogg-Dube (BHS) syndrome, while BHD-associated oncocytomas of the parotid gland are rare. To date, there have been only 11 cases of BHD-associated parotid gland oncocytoma, without a reported case of malignant transformation. We present the first reported case of oncocytic carcinoma of the parotid gland associated with BHD, with radiologic and histologic correlation. This case establishes that BHD-associated parotid oncocytic lesions, previously identified only as benign oncocytomas in the literature to date, can undergo malignant transformation, and should potentially be regarded with a higher index of suspicion and lower threshold for aggressive management.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Squamous Cell Carcinoma Arising in a Parotid Warthin's Tumor: A Case Report and Literature Review

Warthin's tumor is the second most common benign neoplasm of the parotid gland. Epithelial malignant transformation of Warthin's tumor, especially to squamous cell carcinoma, is a rare event. The authors present a case report of a 57-year-old male patient with a mass in the left parotid gland. This paper documents the appearance of squamous cell carcinoma within Warthin's tumor of the left parotid gland and reviews the other similar features of 12 cases.

Distinguishing Parotid Polymorphic Adenoma and Warthin Tumor Based on the CT Radiomics Nomogram: A Multicenter Study

RATIONALE AND OBJECTIVES

To develop, validate, and test a comprehensive radiomics prediction model to distinguish parotid polymorphic adenomas (PAs) and warthin tumors (WTs) using clinical data and enhanced computed tomography (CT) from a multicenter cohort.

MATERIALS AND METHODS

A total of 267 patients with PAs (n =172) or WTs (n = 95) from two hospitals were randomly divided into training (n =188) and validation (n =79) datasets. Radiomics features were extracted from the enhanced CT (arterial phase) followed by dimensionality reduction. Clinical and CT features were combined to establish a prediction model. A radiomics nomogram was constructed by combining RadScore and clinical factors. Moreover, an independent dataset of 31 patients from a third hospital was employed to test the model. Thus, the performance of the nomogram, radiomics signature, and clinical models was evaluated on the training, validation, and the independent testing datasets. Receiver operating characteristic (ROC) curves were used to compare the performance, and decision curve analysis (DCA) was used to evaluate the clinical effectiveness of the model.

RESULTS

A total of 15 radiomics features were selected from CT data as the imaging markers to generate RadScores, and demographics or clinical data like age, sex, and smoking factors combined with RadScores were used to distinguish PAs and WTs based on multivariate logistic regression analyses. The results showed that radiomics nomograms combining clinical factors and RadScores provided satisfactory predictive values for distinguishing PAs from WTs, with areas under ROC curves (AUC) of 0.979, 0.922, and 0.903 for the training, validation, and the independent testing datasets, respectively. Decision curve analysis revealed that the radiomics nomogram outperformed the clinical factor models in terms of accuracy and effectiveness.

CONCLUSION

CT-based radiomics nomograms combining RadScores and clinical factors can be used to identify PAs and WTs, which may help tumor management by clinicians.

A nomogram based on clinical information, conventional ultrasound and radiomics improves prediction of malignant parotid gland lesions

Although conventional ultrasound (CUS) allows for clear detection of parotid gland lesions (PGLs), it fails to accurately provide benign-malignant differentiation due to overlapping morphological features. Radiomics is capable of processing large-quantity volume of data hidden in CUS image undiscovered by naked eyes. The aim was to explore the potential of CUS-based radiomics score (Rad-score) in distinguishing benign (BPGLs) and malignant PGLs (MPGLs). A consecutive of 281 PGLs (197 in training set and 84 in test set) with definite pathological confirmation was retrospectively enrolled. 1465 radiomics features were extracted from CUS images and Rad-score was constructed by using Least Absolute Shrinkage and Selection Operator (LASSO) algorithm. Different nomogram models, including clinic-radiomics (Clin + Rad-score), CUS-clinic (CUS + Clin) and combined CUS-clinic-radiomics (CUS + Clin + Rad-score), were built using logistic regression. The diagnostic performance of different models were calculated and compared by area under receiver operating curve (AUC) and corresponding sensitivity and specificity. Finally, 26 radiomics features were independent signatures for predicting MPGLs, with MPGLs having higher Rad-scores in both cohorts (both P < 0.05). In the test population, CUS + Clin + Rad-score obtained an excellent diagnostic result, with significantly higher AUC value (AUC = 0.91) when compared to that of CUS + Clin (AUC = 0.84) and Clin + Rad-score (AUC = 0.74), respectively (both P < 0.05). In addition, the sensitivity of this combined model was higher than that of single Rad-score model (100.00% vs. 71.43%, P = 0.031) without compromising the specificity value (82.86% vs. 88.57%, P = 0.334). The calibration curve and decision curve analysis also indicated the clinical effectiveness of the proposed combined nomogram. The combined CUS-clinic-radiomics model may help improve the discrimination of BPGLs from MPGLs.

Radiomics and deep learning approach to the differential diagnosis of parotid gland tumors

PURPOSE OF REVIEW

Advances in computer technology and growing expectations from computer-aided systems have led to the evolution of artificial intelligence into subsets, such as deep learning and radiomics, and the use of these systems is revolutionizing modern radiological diagnosis. In this review, artificial intelligence applications developed with radiomics and deep learning methods in the differential diagnosis of parotid gland tumors (PGTs) will be overviewed.

RECENT FINDINGS

The development of artificial intelligence models has opened new scenarios owing to the possibility of assessing features of medical images that usually are not evaluated by physicians. Radiomics and deep learning models come to the forefront in computer-aided diagnosis of medical images, even though their applications in the differential diagnosis of PGTs have been limited because of the scarcity of data sets related to these rare neoplasms. Nevertheless, recent studies have shown that artificial intelligence tools can classify common PGTs with reasonable accuracy.

SUMMARY

All studies aimed at the differential diagnosis of benign vs. malignant PGTs or the identification of the commonest PGT subtypes were identified, and five studies were found that focused on deep learning-based differential diagnosis of PGTs. Data sets were created in three of these studies with MRI and in two with computed tomography (CT). Additional seven studies were related to radiomics. Of these, four were on MRI-based radiomics, two on CT-based radiomics, and one compared MRI and CT-based radiomics in the same patients.

Principles and Applications of Dual Energy Computed Tomography in Neuroradiology

Dual-energy computed tomography (DE CT) is a promising tool with many current and evolving applications. Available DE CT scanners usually consist of one or two tubes, or use layered detectors for spectral separation. Most DE CT scanners can be used in single energy or dual-energy mode, except for the layered detector scanners that always acquire data in dual-energy mode. However, the layered detector scanners can retrospectively integrate the data from two layers to obtain conventional single energy images. DE CT mode enables generation of virtual monochromatic images, blended images, iodine quantification, improving conspicuity of iodinated contrast enhancement, and material decomposition maps or more sophisticated quantitative analysis not possible with conventional SE CT acquisition with an acceptable or even lower dose than the SE CT. This article reviews the basic principles of dual-energy CT and highlights many of its clinical applications in the evaluation of neurological conditions.

The Clinical Characteristics and CT Findings of Parotid and Submandibular Gland Tumours

Objective

To investigate the clinical characteristics and CT findings of parotid and submandibular gland tumours. Materials and methods. From May 2017 to April 2020, all patients with clinically proven parotid and submandibular gland enlargement and palpable masses underwent CT examinations. All patients were confirmed by pathology after surgery. The clinical characteristics and CT features were observed and evaluated. The mean density values before and after enhancement were measured and analyzed. The chi-square test, one-way ANOVA, and Student's t-test were used.

Results

Ninety-four patients with a total of 94 unilateral tumours in the parotid and submandibular glands were enrolled, including 38 pleomorphic adenomas (PAs), 27 Warthin's tumours (WTs), and 29 malignant tumours (MTs). The majority of the PAs (28/38) and MTs (23/29) were located in the parotid gland; the others were located in the submandibular gland. All the WTs were in the parotid gland. The most common benign tumours of the parotid gland were PAs (28/38, 73.7%) and WTs (27/27, 100%), and the most common MTs were mucoepidermoid carcinoma, acinic cell carcinoma, and squamous cell carcinoma (4/29, 13.8%). The most common benign and malignant tumours in the submandibular gland were PAs (10/38, 26.3%) and ductal adenocarcinomas (3/4, 75%). The majority of PA patients (28/38) were female, compared with WT (2/27) (P < 0.001) and malignant tumour patients (10/29) (P < 0.01). A significant difference was also found between WTs and MTs in female patients (P < 0.05). The mean age of PA patients was 43.4 ± 12.1 years, which was lower than that of WTs (62.1 ± 11.7) and MTs (58 ± 14.18) (P < 0.001, P < 0.001, and P=0.244, respectively). On CT imaging, the mean diameter of the PAs and WTs was significantly smaller than that of the MTs (P=0.001 and P < 0.001), and no difference was observed between the PAs and WTs (P=0.275). In the parotid gland, the superficial lobe was more frequently involved than the deep lobe (PAs, 22 : 6; WTs, 17 : 10; and MTs, 15 : 8). The majority of PAs and WTs demonstrated round shapes (25/38, 19/27) and were well defined (30/38, 24/27); by contrast, most MTs were lobulated, irregular shapes (24/29), and ill defined (25/29). On plain CT, the PAs were usually homogeneous, while MTs were frequently heterogeneous, with more necrosis, larger cystic areas, and more haemorrhage or calcification. The mean CT values of PAs, WTs, and MTs were 39.2 ± 3.9 HU, 39.1 ± 3.0 HU, and 37.6 ± 3.1 HU (P > 0.05), respectively. On contrast CT, the WTs were significantly enhanced compared with MTs and PAs, with mean CT values of 53.5 ± 4.0 HU, 84.4 ± 6.0 HU, and 65.2 ± 3.8 HU, respectively (all P < 0.001). The mean CT value changes for PAs, WTs, and MTs (∆) were 14.4 ± 3.0 HU, 45.3 ± 4.5 HU, and 27.7 ± 2.5 HU, respectively. Significant differences were observed between ∆_PAs and ∆_WTs, ∆_PAs and ∆_MTs, and ∆_WTs and ∆_MTs (all P < 0.001).

Conclusion

Parotid and submandibular gland tumours have some typical clinical characteristics and CT findings, and plain and early contrast-phase CT combined with clinical parameters may be helpful for diagnosis.

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

Purpose/Objectives(s)

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

Materials/Methods

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

Results

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

Conclusion

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

Differentiation of Benign and Malignant Parotid Gland Tumors with MRI and Diffusion Weighted Imaging

Objective

This study investigated the effectivity of Magnetic Resonance Imaging (MRI) findings and Apparent Diffusion Coefficient (ADC) value in evaluating parotid gland tumors (PGTs), and aimed to reduce the biopsy procedure before surgery.

Methods

This retrospective study included 54 PGTs of 42 patients' (24 female, 18 male, mean age; 51.4±15.9). All of the patients had an MRI, and histopathologic diagnosis. The signal intensity [T1 and T2 Weighted (W), T1W after intravenous contrast agent injection] and mean ADC values of the PGTs were measured. Also contrast enhancement pattern (homogenous, heterogeneous, peripheral or none), margin features (well or ill-defined), sizes, location (superficial lobe/deeplobe/both), perineural spread, presence of lymphadenopathy, and extension to adjacent structures were noted.

Results

The distribution of PGTs was; 21 pleomorphic adenomas, 18 Warthin tumors, 2 lymph nodes, 2 mucoepidermoid carcinomas, 5 adenoid cystic carcinoma, 1 basal cell carcinoma,2 metastases and 2 lymphomas; (13 malignant and 41 benign lesions). Morphologic parameters; ill-defined margin, perineural spread, lymphadenopathy, and extension to adjacent structures were found to be significantly associated with malign lesions (p<0.01). There was a significant difference between ADC values of malignant and benign PGTs (p<0.05). Also ADC values and T2 signal intensity was significantly lower in Warthin tumors rather than pleomorphic adenomas (p<0.05).

Conclusions

Mean ADC values when considered with morphological features may be accessible methods to distinguish benign and malignant PGTs, also ADC values and T2 signal intensity may be useful for differentiating pleomorphic adenomas from Warthin tumors, thereby reducing the number of biopsies and thus complications.

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.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

A case report of a rare nasopharyngeal myoepithelial dominant pleomorphic adenoma

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

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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.

Differential Diagnosis of Solitary Fibrous Tumor/Hemangiopericytoma and Angiomatous Meningioma Using Three-Dimensional Magnetic Resonance Imaging Texture Feature Model

Background

Intracranial solitary fibrous tumor(SFT)/hemangiopericytoma (HPC) is an aggressive malignant tumor originating from the intracranial vasculature. Angiomatous meningioma (AM) is a benign tumor with a good prognosis. The imaging manifestations of the two are very similar. Thus, novel noninvasive diagnostic method is urgently needed in clinical practice. Texture analysis and model building through machine learning may have good prospects.

Aim

To evaluate whether a 3D-MRI texture feature model could be used to differentiate malignant intracranial SFT/HPC from AM.

Method

A total of 97 patients with SFT/HPC and 95 with AM were included in this study. Patients from each group were randomly divided into the train (70%) and test (30%) sets. ROIs were drawn along the edge of the tumor on each section of T1WI, T2WI, and contrasted T1WI using ITK-SNAP software. The segmented image was imported into the AK software for texture feature extraction, and the 3D ROI signal intensity histograms of T1WI, T2WI, and contrasted T1WI were automatically obtained along with all the parameters. Modeling was performed using the language R. Confusion matrix was used to analyze the accuracy of the model. ROC curve was constructed to assess the grading ability of the logistic regression model.

Results

After Lasso dimension reduction, 5, 9, and 7 texture features were extracted from T1WI, T2WI, and contrasted T1WI, respectively; additional 8 texture features were extracted from the combined sequence for modeling. The ROC analyses on four models resulted in an area under the curve (AUC) of 0.885 (sensitivity 76.1%, specificity 87.9%) for T1WI model, 0.918 (73.1%, 95.5%) for T2WI model, 0.815 (55.2%, 93.9%) for contrasted T1WI model, and 0.959 (92.5%, 84.8%) for the combined sequence model and were enough to correctly distinguish the two groups in 71.2%, 81.4%, 69.5%, and 83.1% of cases in test set, respectively.

Conclusions

The radiological model based on texture features could be used to differentiate SFT/HPC from AM.

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.

Squamous cell carcinoma arising from Warthin's tumor in the parotid gland

The malignant transformation of Warthin’s tumor in the parotid gland is extremely rare. In addition, among the various types of the malignant change of Warthin’s tumor, squamous cell carcinoma is the rarest one. The pathogenesis of this rare disease entity is uncertain till now. Also the most effective treatment and long-term prognosis are not yet clear. Up to present, there are a few reports that only described the pathologic and clinical features of this tumor. However, there is no report about the imaging findings of this rare tumor. We report the imaging features in a case of squamous cell carcinoma arising from Warthin’s tumor in the parotid gland.

Basal cell adenoma and myoepithelioma of the parotid gland: patterns of enhancement at two-phase CT in comparison with Warthin tumor

PURPOSE

Early enhancement and a washout pattern are reported to be the characteristic imaging features of Warthin tumor (WT). The purpose of this study was to evaluate the enhancement patterns of basal cell adenoma (BCA) and myoepithelioma (ME) of the parotid gland on two-phase computed tomography (CT), compared with WT.

METHODS

We retrospectively evaluated two-phase CT examinations of histologically proven 19 BCAs, 12 MEs, and 23 WTs of the parotid gland. In all patients, CT scans were obtained at early and delayed phases with scanning delays of 40 and 180 s, respectively. We measured the attenuation values on each phase of CT scans and calculated washout attenuation and relative percentage enhancement washout ratio. From the data acquired, we statistically compared the enhancing characteristics among three tumor groups.

RESULTS

Based on the results of washout attenuation and relative percentage enhancement washout ratio, 15 (79%) of 19 BCAs, 9 (75%) of 12 MEs, and 23 (100%) of 23 WTs demonstrated a washout pattern of enhancement on two-phase CT scans. Despite variations of the individual tumors, both parameters revealed no significant difference among three tumor groups.

CONCLUSION

BCAs and MEs of the parotid gland frequently show early enhancement and a washout pattern on two-phase CT, which can be indistinguishable from WTs in the majority of cases.

Delayed enhancement in differential diagnosis of salivary gland neoplasm

Background

Multi-phasic Computed Tomography (CT) evaluation allows to study the enhancement features of parotid gland masses. The aim of our study was to evaluate the role of delayed enhancement in the characterization of different histologic types of parotid tumours.

Methods

Forty-eight patients (22 male and 26 female) with at least one parotid gland tumor, were included in our study. Multi-phase CT images were obtained before and 30, 120 s and 8 minutes after intravenous contrast injection. The images were evaluated by two radiologists for lesion enhancement degree. A quantitative assessment was performed using a region of interest on each lesion and density changes between different phases were compared. The tumoral enhancement ratio was calculated between the 8 minutes delayed and the early (30 s) phase. The pathological diagnosis was confirmed in all patients after surgery.

Results

All patients had unilateral lesion for a total of 48 lesions. Twenty-eight were pleomorphic adenomas, 15 Warthin's tumours and 5 carcinomas. All Warthin tumours showed a rapid contrast enhancement at the early phase (30 sec) followed by a progressive wash-out during the delayed scans. Most of pleomorphic adenomas (89.2%) showed the highest density at the 8-minutes delayed phase. Malignant tumours showed slower contrast enhancement and 3 out of 5 (60%) showed a marked decrease at the 8 minutes delayed phase while the remaining 2 (40%), did not show any density reduction. The tumoral enhancement ratio was significantly different between Warthin tumours and pleomorphic adenomas and between Warthin's and malignant tumours.

Conclusions

Multi-phasic CT examination with 8 minutes delayed acquisition has shown to be useful in parotid gland lesion differentiation.

Multiphase contrast-enhanced computed tomography imaging features of salivary duct carcinoma: differentiation from other salivary gland malignancies

OBJECTIVE

The aim of this study was to investigate the imaging features of salivary duct carcinoma (SDC) with multiphase contrast-enhanced computed tomography (CECT) and to compare them with those of mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (ACC), and acinic cell carcinoma.

STUDY DESIGN

A total of 63 patients with histologically diagnosed salivary gland malignancies underwent preoperative multiphase CECT. Clinical information, location, size, mass pattern, enhancement pattern, borders, invasion of adjacent tissues, and lymph node metastasis were evaluated. Computed tomography (CT) number attenuation patterns were calculated.

RESULTS

SDCs were significantly more common in males and in the parotid gland (P ≤ .018). They were more likely to invade into adjacent tissues and metastasize to lymph nodes (P ≤ .032). Six SDCs (66.7%) had comedonecrosis, as detected on histopathologic examination, and 3 lesions presented cribriform necrosis on CECT. CT numbers during delayed-phase scanning were significantly higher in SDC than in ACC (P = .031). Significant differences were discovered between MEC and ACC for CT numbers during arterial-phase scanning (P = .047) and in the ratio of CT numbers (P = .018).

CONCLUSIONS

SDC exhibits some specific CT features, and multiphase CECT imaging is useful in the differential diagnosis of salivary gland malignancies.

The key radiologic and cytomorphologic features of oncocytic and oncocytoid lesions of the salivary gland

Oncocytic and oncocytoid lesions represent a distinct subset of salivary gland lesions. True oncocytic lesions of the salivary gland are entirely composed of oncocytes. These are characterized by the presence of abundant eosinophilic granules due to the presence of abundant cytoplasmic mitochondria. Oncocytic lesions of the salivary gland include oncocytosis, oncocytoma, and oncocytic carcinoma. In addition to the true oncocytic lesion, there exists another group of salivary gland lesions, which demonstrate cells with abundant and occasionally granular cytoplasm. These are often termed as "oncocytoid" lesions. The recently proposed Milan System for reporting salivary gland cytology clearly states that fine-needle aspiration specimens representing oncocytic/oncocytoid lesions of salivary gland cannot effectively distinguish between a nonneoplastic lesion, benign and malignant neoplasms. Therefore, most lesions lacking classic cytomorphologic features will be classified under the umbrella diagnostic term of "Salivary Gland Neoplasm of Uncertain Malignant Potential" (SUMP). In this review, we discuss and illustrate key clinicopathologic and radiologic features that can help the practicing cytopathologist narrow down the differential and provide the best management based diagnosis.

Diagnostic Accuracy of Multiparametric Magnetic Resonance Imaging for Differentiation Between Parotid Neoplasms

PURPOSE

This study was designed to evaluate the role of multiparametric magnetic resonance imaging (MRI) for differentiation of parotid gland neoplasms.

METHODS

Prospective study was conducted upon 52 consecutive patients (30 men, 22 women; aged 24-78 years; mean, 51 years) with parotid tumours that underwent multiparametric MRI using combined static MRI, dynamic contrast enhanced (DCE) MRI, and diffusion-weighted imaging (DWI). The static MRI parameter, time signal intensity curves (TIC) derived from DCE-MRI, and apparent diffusion coefficient (ADC) values of parotid tumours were correlated with histopathological findings.

RESULTS

Static MRI revealed a significant difference between both benign and malignant lesions in regards to margin definition (P < .001) and T2 hypointensity (P < .013), with a diagnostic accuracy 95% and 78.33% respectively. Study of the TIC type on DCE-MRI revealed statistically significant difference between benign and malignant lesions (P < .001) and diagnostic accuracy 96.55%. There was no statistically significant difference (P = .181) between the ADC values of benign and malignant lesions. ROC curve analysis revealed that by using ADC cut-off value of 1 × 10^-3 mm²/s had accuracy of 84.62% respectively for differentiating Warthin from malignant tumours that could be modified to higher value (94.28%) by excluding lymphoma from malignant lesions. By using cutoff value of 1.3 × 10^-3 mm²/s to differentiate pleomorphic adenoma from malignancy, ROC curve analysis had high accuracy of 97.06%.

CONCLUSION

Multiparametric MRI can be used for differentiation of malignant from benign parotid tumours and characterization of some benign parotid tumours.

Contrast-enhanced Multi-detector CT Examination of Parotid Gland Tumors: Determination of the Most Helpful Scanning Delay for Predicting Histologic Subtypes

Purpose:

Although contrast-enhanced CT (computed tomography) is regarded as the preoperative imaging modality of choice for parotid gland tumor, scanning methods are highly variable. We aimed at determining the most helpful scanning delay for predicting histologic subtypes of parotid gland tumors.

Material and Methods:

Based on the medical record review, we identified 293 patients with 296 parotid gland tumors who underwent uni- or biphasic neck CT examination using a 64-row detector CT with the same acquisition parameters except the scan delays that were: (1) unenhanced, (2) 40 seconds, (3) 50 seconds, and (4) 70 seconds after the beginning of contrast-media injection. Pathologically, the gland tumors (mean size: 26 ± 10.4 mm) consisted of 164 pleomorphic adenomas, 78 Warthin tumors, 23 other benign tumors, and 31 malignant tumors. The mean CT attenuation values (MAV)s from 419 CT images with different scan delays were compared by analysis of variance (ANOVA).

Results:

On enhanced CT with a 50-second scan delay, Warthin tumors most intensely enhanced and could be distinguished from pleomorphic adenomas and malignant tumors (both p < 0.05). However, with other scan delays, there were no significant differences in MAV between all histologic subtypes of tumors.

Conclusion:

Prediction of histologic subtype, by differentiating Warthin from non-Warthin tumors, was possible only with CT scanning beginning 50 seconds after the start of contrast injection.

Contrast-Enhanced CT with Knowledge-Based Iterative Model Reconstruction for the Evaluation of Parotid Gland Tumors: A Feasibility Study

Objective

The purpose of this study was to determine the diagnostic utility of low-dose CT with knowledge-based iterative model reconstruction (IMR) for the evaluation of parotid gland tumors.

Materials and Methods

This prospective study included 42 consecutive patients who had undergone low-dose contrast-enhanced CT for the evaluation of suspected parotid gland tumors. Prior or subsequent non-low-dose CT scans within 12 months were available in 10 of the participants. Background noise (BN), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were compared between non-low-dose CT images and images generated using filtered back projection (FBP), hybrid iterative reconstruction (iDose⁴; Philips Healthcare), and knowledge-based IMR. Subjective image quality was rated by two radiologists using five-point grading scales to assess the overall image quality, delineation of lesion contour, image sharpness, and noise.

Results

With the IMR algorithm, background noise (IMR, 4.24 ± 3.77; iDose⁴, 8.77 ± 3.85; FBP, 11.73 ± 4.06; p = 0.037 [IMR vs. iDose⁴] and p < 0.001 [IMR vs. FBP]) was significantly lower and SNR (IMR, 23.93 ± 7.49; iDose⁴, 10.20 ± 3.29; FBP, 7.33 ± 2.03; p = 0.011 [IMR vs. iDose⁴] and p < 0.001 [IMR vs. FBP]) was significantly higher compared with the other two algorithms. The CNR was also significantly higher with the IMR compared with the FBP (25.76 ± 11.88 vs. 9.02 ± 3.18, p < 0.001). There was no significant difference in BN, SNR, and CNR between low-dose CT with the IMR algorithm and non-low-dose CT. Subjective image analysis revealed that IMR-generated low-dose CT images showed significantly better overall image quality and delineation of lesion contour with lesser noise, compared with those generated using FBP by both reviewers 1 and 2 (4 vs. 3; 4 vs. 3; and 3–4 vs. 2; p < 0.05 for all pairs), although there was no significant difference in subjective image quality scores between IMR-generated low-dose CT and non-low-dose CT images.

Conclusion

Iterative model reconstruction-generated low-dose CT is an alternative to standard non-low-dose CT without significantly affecting image quality for the evaluation of parotid gland tumors.

Basal cell adenoma in the parapharyngeal space resected via trans-oral approach aided by endoscopy: Case series and a review of the literature

RATIONALE

Basal cell adenoma (BCA) is a rare benign salivary gland tumor. It is difficult to be completely resected when arising in parapharyngeal space. A contemporary trend is to develop minimally invasive approaches on the premises of safety and complete resection.

PATIENT CONCERNS

Three patients were referred to our ENT Outpatient Department with the chief complaint of an uncomfortable throat. CT or MRI revealed a unilateral mass in the parapharyngeal space, round or oval in shape, with well-defined borders.

DIAGNOSES

CT and MRI provided useful information for the preoperative evaluation. The appearance of large-scale cystic components may be an important clue for the diagnosis of BCA. PET/CT images were also available in one case. The final diagnoses were all basal cell adenomas (tubular type) in parapharyngeal space according to the regular histopathological examination after surgery.

INTERVENTIONS

All three cases were completely resected by a trans-oral approach. The average operative time and estimated blood loss were 86 (range, 61-106) min and 116.7 (range, 50-200) mL, respectively. Endoscopy was used in the largest case to further assess the residual cavity after the complete resection and hemostasis.

OUTCOMES

Postoperative recovery courses were quick and uneventful, with no neurovascular complication. Patients were discharged on the 3-5 day after surgery on an oral diet. One patient reported symptoms of velopharyngeal incompetence, manifested as mild slurred speech and nighttime salivation, for up to 3 months, which recovered spontaneously thereafter. There was no evidence of recurrence in the follow-up period.

LESSONS

In our experience, the trans-oral approach appeared to be effective, safe, and less invasive for extirpation of selected basal cell adenomas in the parapharyngeal space. An assistance of endoscopy facilitates the surgery.

Diagnostic value of single-source dual-energy spectral computed tomography in differentiating parotid gland tumors: initial results

Background

An accurate preoperative diagnosis that helps distinguish between benign and malignant parotid gland tumors is very important because the results strongly affect surgical procedures. We aimed to evaluate the value of single-source dual-energy computed tomography (ssDECT) in differentiating malignant from benign parotid gland tumors.

Methods

Fifty patients underwent enhanced neck ssDECT scanning before surgery. The images were analyzed using the gemstone spectral imaging (GSI) viewer software.

Results

Fifty-two tumors (43 patients) were confirmed histopathologically, comprising of 12 pleomorphic adenomas (PAs), 24 Warthin tumors (WTs) (15 patients), and 16 malignant tumors (MTs). The iodine concentration (IC), normalized iodine concentration to common carotid artery (NIC_A) and slope value of the spectral curve (λ_HU) of the WTs were significantly higher than those of MTs and PAs (all P<0.05). The optimal IC, NIC_A and λ_HU thresholds for differentiating PAs from MTs were 0.91 mg/mL, 0.15 and 1.09, respectively, achieving sensitivities of 91.7%, 91.7% and 91.7%, specificities of 95.0%, 85.0% and 95.0%, and accuracies of 94.2%, 86.5% and 94.2%, respectively for distinguishing PAs from MTs. The optimal IC, NIC_A and λ_HU thresholds for distinguishing WTs from MTs were 1.46 mg/mL, 0.20 and 1.72, achieving sensitivities of 91.7%, 95.8% and 91.7%, and specificities of 89.3%, 85.7% and 89.3%, respectively. The accuracy was 90.4%, 90.4% and 90.4%, respectively.

Conclusions

The parameters of ssDECT in enhanced CT scans are useful in the differential diagnosis of parotid tumors.

Role of Computed Tomography (CT) in Localisation and Characterisation of Suprahyoid Neck Masses

Background

Suprahyoid neck lesions are difficult to assess only by means of clinical inspection and therefore imaging techniques are required to precisely evaluate suprahyoid neck spaces. The aim of this study was to evaluate the distinctive role of computed tomography in the assessment of anatomical source and pathological type of masses involving the suprahyoid neck spaces.

Material/Methods

Sixty patients presenting with suprahyoid neck masses underwent computed tomography of the neck. The CT findings were correlated with histopathological findings and a final diagnosis was made.

Results

Overall, male preponderance was seen except in the case of parotid space lesions where female predominance was seen. The most common aetiology was squamous cell carcinoma and the majority of cases (30%) were seen in patients aged 41–50 years. The majority of lesions were found in the pharyngeal mucosal space (n=16) with squamous cell carcinoma being the most common pathology. In the parotid space, pleomorphic adenoma and in the prestyloid parapharyngeal space, squamous cell carcinoma were the most common lesions, respectively. In the retropharyngeal space, an equal incidence of malignant and inflammatory aetiologies was seen. Abscesses were the most common lesions in the prevertebral space. The pleomorphic adenoma was the most common benign tumour and was also the second most common tumour in the suprahyoid neck spaces. CT had an excellent correlation with histopathological findings with sensitivity of 96.4%, specificity of 100%, positive predictive value of 100% and a negative predictive value of 91.67%.

Conclusions

Computed tomography definitely has a major role to play in the evaluation of suprahyoid neck masses as it has an excellent correlation with post-operative histopathological diagnosis.

Dual-energy CT applications in salivary gland lesions

The increasing availability of dual-energy CT (DECT) has set the stage for an exciting era in CT technology. This technique is extensively used throughout the world with numerous centres working on the applications of DECT in various radiology subspeciality areas. DECT provides many advantages over the conventional single-energy scan. Instead of a single set of images, radiologists have access to multiple sets of images from a single acquisition. The DECT workstation enables the reader to generate images, according to the clinical setting, in order to answer a specific clinical question. Radiologists should be aware of the basic concepts of DECT and the usefulness of each image data set. This article aimed to describe the basic principles, techniques and applications of DECT in the imaging of salivary gland lesions. The specific roles of each image data set, in the context of salivary gland lesions, are also discussed.

Myoepithelial carcinoma of the salivary gland: pathologic and CT imaging characteristics (report of 10 cases and literature review)

OBJECTIVE

To summarize the pathologic and computed tomography (CT) imaging characteristics of myoepithelial carcinoma in the salivary gland.

STUDY DESIGN

Ten patients with myoepithelial carcinoma of the salivary gland underwent enhanced CT scanning, and the pathologic and CT imaging features were evaluated, including the pathologic type, size, margin morphology, and enhancement pattern of the lesions.

RESULTS

Myoepithelial carcinoma had a multinodular or lobulated outline. The cut surfaces were gray-brown with no or incomplete capsules, and visible bleeding was observed in some cases. The pathologic cell type of the tumor was spindle-shaped, clear, plasmacytoid, or epithelioid cells or a mixture of cell types. Nonenhanced CT imaging showed an irregular lobulated or multinodular lesion with ill-defined margins and inhomogeneous attenuation and punctate calcification in a minority of the lesions. The enhanced CT imaging results revealed moderate and intense inhomogeneous enhancement, including cystic and slit-like regions with no enhancement, intense nodular enhancement, and small tortuous vessels in the arterial phase.

CONCLUSION

The pathologic features and CT imaging findings of myoepithelial carcinoma were characteristic, and familiarity with these imaging findings might aid in the diagnosis of this entity.

MRI and CT imaging characteristics of myoepithelioma of the parotid gland

BACKGROUND

Myoepithelioma is a rare tumor of the salivary gland and only few reports have focused on its imaging characteristics.

PURPOSE

To characterize the magnetic resonance imaging (MRI) and computed tomography (CT) characteristics of myoepithelioma of the parotid gland.

MATERIAL AND METHODS

We retrospectively analyzed the MRI and CT findings of nine patients with myoepithelioma in the parotid gland as demonstrated by pathologic analysis. The MRI and CT findings were analyzed regarding the tumor position, size, marginal morphology, and degree and patterns of enhancement.

RESULTS

Unilocular and multilocular tumors were found in seven cases (7/9, 77.8%) and two cases (2/9, 22.2%), respectively. Most of the tumors were located in the superficial lobe (6/9, 66.7%) and abutted the capsule of the parotid gland (7/9, 77.8%). Six of the seven unilocular tumors were round. Most of the tumors displayed smooth contours (6/9, 66.7%) and well-defined margins (5/9, 55.6%). Four of five tumors (80%) display the capsule on T2-weighted (T2W) and contrast-enhanced T1-weighted (T1W) imaging. All five examined tumors exhibited homogeneous intermediate signal intensity on T1W imaging and high signal intensity on T2W imaging. On contrast-enhanced T1W imaging, the tumors displayed homogeneous (n = 4) or heterogeneous (n = 1) moderate to marked contrast enhancement. Based on the enhanced CT scans, four tumors exhibited moderate homogeneous (n = 2) or heterogeneous (n = 2) contrast enhancement.

CONCLUSION

Myoepitheliomas are characterized as small, unilocular, round tumors with smooth contours that are located in the superficial lobe and abut the capsule of the parotid gland, display the capsule on T2W and contrast-enhanced T1W imaging, and exhibit homogeneous signal intensities or densities based on MRI and CT.

Metastatic pleomorphic adenoma to the supraspinatus muscle: a case report and review of a rare aggressive clinical entity

We report a case of a 65-year-old female with a recurrent right parotid pleomorphic adenoma (PA) 24 years after initial surgical excision. Positron-emission tomography (PET) and computed tomography (CT) demonstrated an unusual suspicious FDG-avid erosive rim enhancing mass centered in the right supraspinatus muscle. Cytology from CT-guided aspiration of the mass was consistent with a histologically benign PA, and the patient was diagnosed with metastatic pleomorphic adenoma (MPA). The patient later developed diffuse pulmonary metastases and died within 3 months. MPA, although rare, is recognised as a potentially lethal malignant complication of recurrent or longstanding benign PA. As no biochemical or genetic parameters are predictive of malignant change, patients presenting with recurrent PA should be considered for screening for metastatic disease.

Sinonasal Angiomatous Polyp: Evaluation With 2-Phase Helical Computed Tomography

Sinonasal angiomatous polyp (SAP) is a rare benign nontumorous lesion and previously considered lack of characteristic computed tomography (CT) findings. This study aimed to evaluate 2-phase helical CT for characterization of SAP. Twelve patients with pathologically confirmed SAP underwent 2-phase helical CT preoperatively. After injection of 80 mL contrast material at a rate of 3 mL/s, early and delayed phases were obtained with delays of 30 and 120 s, respectively. The degree and pattern of enhancement were visually analyzed. The attenuation changes were also analyzed quantitatively by measuring CT values and compared with those of the internal maxillary artery (IMA). All 12 cases showed vessel-like marked heterogeneous enhancement at both early and delayed phases. An irregular linear, nodular, and patchy enhancement pattern was found at the early phase, and enlarged and fused together, that is, progressive enhancement pattern was found at the delayed phase. There was no significant difference between the CT values of SAP and those of the IMA at the plain, arterial phase, and delayed phase (53 ± 6 Hounsfield units [HU] vs 56 ± 7 HU, 187 ± 56 HU vs 209 ± 71 HU, and 143 ± 22 HU vs 139 ± 19 HU, respectively, P = 0.361, 0.429, and 0.613, respectively). Vessel-like marked heterogeneous enhancement was a characteristic CT feature of SAP, and progressive enhancement on 2-phase helical CT could further convince the diagnosis.

Synchronous unilateral basal cell adenoma of the parotid gland: A case report

The current study reports the case of a 68-year-old male who presented with a 4-month history of a painless slow-growing mass in the left parotid region. Magnetic resonance imaging revealed two independent, round lesions in the superficial and deep lobes of the parotid gland on the left side, respectively. A total parotidectomy was performed and basal cell adenomas (BCAs) were identified by histopathological examination. At the 6-month follow-up examination, no sign of recurrence was found. This study describes the clinical features of a rare case of synchronous unilateral BCA in the parotid gland and also provides a review of the literature.

Two-phase helical computed tomography study of salivary gland warthin tumors: a radiologic findings and surgical applications

Objectives

The goal of this study was to define the radiologic characteristics of two-phase computed tomography (CT) of salivary gland Warthin tumors and to compare them to pleomorphic adenomas. We also aimed to provide a foundation for selecting a surgical method on the basis of radiologic findings.

Methods

We prospectively enrolled 116 patients with parotid gland tumors, who underwent two-phase CT preoperatively. Early and delayed phase scans were obtained, with scanning delays of 30 and 120 seconds, respectively. The attenuation changes and enhancement patterns were analyzed. In cases when the attenuation changes were decreased, we presumed Warthin tumor preoperatively and performed extracapsular dissection. When the attenuation changes were increased, superficial parotidectomy was performed on the parotid gland tumors. We analyzed the operation times, incision sizes, complications, and recurrence rates.

Results

Attenuation of Warthin tumors was decreased from early to delayed scans. The ratio of CT numbers in Warthin tumors was also significantly different from other tumors. Warthin tumors were diagnosed with a sensitivity of 96.1% and specificity of 97% using two-phase CT. The mean operation time was 38 minutes and the mean incision size was 36.2 mm for Warthin tumors. However, for the other parotid tumors, the average operation time was 122 minutes and the average incision size was 91.8 mm (P<0.05).

Conclusion

Salivary Warthin tumor has a distinct pattern of contrast enhancement on two-phase CT, which can guide treatment decisions. The preoperative diagnosis of Warthin tumor made extracapsular dissection possible instead of superficial parotidectomy.

Salivary gland tumors of the parotid gland: CT and MR imaging findings with emphasis on intratumoral cystic components

INTRODUCTION

The purpose of this study was to assess computed tomography (CT) and magnetic resonance (MR) imaging findings of salivary gland tumors of the parotid gland with emphasis on intratumoral cystic components.

METHODS

Seventy-two histopathologically confirmed salivary gland tumors of the parotid gland (44 benign and 28 malignant), which underwent both CT and MR imaging including contrast-enhanced study, were included in this study. We retrospectively reviewed images for the presence, number, occupying rate, margin characteristics, distribution, and predominant MR signal intensity of intratumoral cystic components.

RESULTS

The prevalence of cystic components was greater in malignant than benign tumors (79 vs. 50%, p < 0.05). The number and occupying rate were similar between benign and malignant tumors. The irregular margins were more frequent in malignant than benign tumors (73 vs. 27%, p < 0.01). The frequency of eccentric location was greater in benign than malignant tumors (91 vs. 55%, p < 0.01), whereas the frequency of centric location was greater in malignant than benign tumors (32 vs. 0%, p < 0.01). On T1-weighted images, the frequency of hyperintensity was greater in benign than malignant tumors (50 vs. 9%, p < 0.01), whereas that of isointensity was greater in malignant than benign tumors (50 vs. 0%, p < 0.01). Multiple logistic regression analysis showed that the absence of irregular margins of cystic components only was significantly correlated with the presence of benign salivary gland tumors (p < 0.01).

CONCLUSION

Imaging features of intratumoral cystic components may help to differentiate benign from malignant tumors of the parotid salivary gland.

Ultrasound and computed tomography features of primary acinic cell carcinoma in the parotid gland: a retrospective study

OBJECTIVE

The aim of this study was to characterize the ultrasound (US) and computed tomography (CT) findings of primary acinic cell carcinoma (AciCC) of the parotid gland.

SUBJECTS AND METHODS

Seventy patients (70 lesions) with histopathologically proven AciCC underwent US or CT examination. The following characteristics were assessed on US images: size, shape, border, echogenicity, echotexture, internal structure, distal acoustic enhancement, and vascularity. The following characteristics were evaluated on CT images: size, shape, border, density, CT values on plain and contrast-enhanced scans, enhancement pattern, enhancement degree, and surrounding bone destruction.

RESULTS

On US images, lesions were irregular, well-defined, hypoechoic, heterogeneous, and poorly vascularized. On CT images, lesions were regular and well-defined, and showed slight heterogeneous enhancement.

CONCLUSION

These findings suggest that most primary AciCCs show benign features on US and CT.

Diagnostic value of CT perfusion imaging for parotid neoplasms

OBJECTIVES

To assess the value of CT perfusion imaging in the differentiation of different histological categorization of benign tumours from malignant tumours in patients with parotid neoplasms.

METHODS

CT perfusion was successfully performed in 62 patients with parotid neoplasms whose diagnoses were confirmed by surgery or biopsy. The software generated a tissue time-density curve (TDC) and measured blood volume, blood flow, mean transit time and capillary permeability surface product. One-way ANOVA and receiver operating characteristic curves were used to analyse the difference and diagnostic efficacies of all perfusion data between each one of the benign tumours and malignancies. Statistical significance was assigned at the 5% level.

RESULTS

Pleomorphic adenomas mainly had a gradually ascending TDC. Warthin tumours showed a fast ascent followed by a fast descent. The TDC of basal cell adenomas had a fast ascension followed by a plateau, then a gradual descent. Malignant tumours mainly showed a rapidly ascending curve with a stable plateau. Significant differences were observed in blood flow, blood volume and mean transit time between pleomorphic adenomas and malignant tumours (p < 0.05) as well as in blood flow and blood volume between the Warthin tumours, the basal cell adenomas and the malignant tumours (p < 0.05). Differences in permeability surface between the basal cell adenomas and malignant tumours were significant (p < 0.01).

CONCLUSION

CT perfusion of parotid gland could provide TDC and perfusion data, which were useful in the differentiation of different histological benign tumours and malignant tumours in the parotid gland.

Two-phase computed tomography study of warthin tumor of parotid gland: differentiation from other parotid gland tumors and its pathologic explanation

OBJECTIVE

The objective of this study was to define the radiological characteristics of 2-phase computed tomography (CT) of parotid gland Warthin tumors (WTs) with a pathologic basis for these findings.

METHODS

We prospectively enrolled 116 patients with parotid gland tumor who underwent preoperative 2-phase CT scans(scanning delays of 30 and 120 seconds). The attenuation changes and enhancement patterns were analyzed according to pathology. We also evaluated size-matched samples of WTs and pleomorphic adenoma by staining CD31, vascular endothelial growth factor-receptor 2, collagen IV, and smooth muscle actin.

RESULTS

Computed tomography numbers in WTs were significantly higher than those in other tumors in early-phase scans and lower in delayed scans. Pathologically, CD31(+) blood vessel area was significantly higher in WTs than in pleomorphic adenomas. In addition, WTs had an extensive capillary network and many leaky blood vessels.

CONCLUSIONS

The enhancement pattern of early fill-in and early washout is the typical finding of WTs on 2-phase CT scans, which may be attributed pathologically to abundant blood vessel and extensive capillary network.

A case of cystadenocarcinoma of the ectopic salivary gland: comparison of pre-operative ultrasound, CT and MR images with the pathological specimen

Cystadenocarcinoma is a rare salivary gland tumour. Only a few case studies have provided pre-operative images of these tumours. This report demonstrates the case of a 28-year-old male with cystadenocarcinoma arising from an ectopic salivary gland with lymph node metastasis in the right upper neck. Ultrasound including Doppler images showed two masses with scant vascular flow. One was a hyperechoic mass enclosed within a low echoic cystic lesion and the other was a solid hypoechoic mass. Contrast enhancement CT scans demonstrated a ring enhanced mass and weakly homogeneous enhanced masses in the right upper neck. Dynamic studies showed increased enhancement in delayed phase CT that was the same as that in other malignant salivary gland tumours. Moderate to slightly high signal intensity was seen on T(1) weighted MR images and axial T(2) weighted MR images showed one heterogeneous mass in a high signal lesion and a moderate to high signal intensity mass. The authors discuss the pre-operative findings of ultrasound with Doppler imaging of this neoplasm, and CT findings including dynamic study images and MRI, comparing the findings with the post-operative pathological features of the tumour.

Real-time sonoelastography of major salivary gland tumors

OBJECTIVE

The purpose of this study was to determine the performance of real-time sonoelastography in the differential diagnosis of salivary gland tumors.

SUBJECTS AND METHODS

Between 2007 and 2010, 74 salivary gland tumors were examined by ultrasound and sonoelastography in 66 patients. Lesions were graded according to a 4-point elastography score. Surgical excision and histopathologic examination were performed in all cases. The difference in elastographic score between benign and malignant masses and that between pleomorphic adenomas and Warthin tumors were evaluated.

RESULTS

Of the 74 salivary tumors, 63 were located in the parotid, and 11 were in the submandibular gland. There were 18 malignant and 56 benign tumors. The mean (± SD) elastographic score was 2.58 ± 0.87 for pleomorphic adenomas, 2.15 ± 0.80 for Warthin tumors, 2.00 ± 0.57 for other benign tumors, and 2.94 ± 0.87 for malignant tumors. For benign tumors overall, the mean elastographic score was 2.41 ± 0.87. The difference in elastographic score between benign and malignant tumors overall was statistically significant (p < 0.05), but the difference between malignant tumors and pleomorphic adenomas and that between Warthin tumors and pleomorphic adenomas were not statistically significant. Using cutoff values between scores 2 and 3 and scores 3 and 4, there was no statistically significant difference between benign and malignant tumors.

CONCLUSION

Although this study revealed a difference in elastographic score between benign and malignant tumors, detailed analysis did not provide consistent results. Consequently, real-time sonoelastography appears to be a limited technique in the differential diagnosis between benign and malignant salivary masses.

CT and ultrasound features of basal cell adenoma of the parotid gland: a report of 22 cases with pathologic correlation

BACKGROUND AND PURPOSE

Parotid gland BCA is a rare benign tumor. Only a few studies describing the imaging features of BCA have been published. This study investigated CT and sonography characteristics of BCA of the parotid gland.

MATERIALS AND METHODS

Demographics of patients with BCA were evaluated, and lesion characteristics of CT (n = 22) and sonography (n = 20) were reviewed. These cases were grouped into 3 types: type 1 tumors, located at the superficial region of superficial lobe of the parotid gland; type 2 tumors, located at the deeper region of superficial lobe; and type 3 tumors, located in the deep lobe. Imaging findings were correlated with pathology.

RESULTS

Sixteen patients (73%) were female and 6 (27%) were male. The mean age was 51.5 years (SD 10.2; range 32-73). The size of the tumors was less than 30 mm. The sizes of type 1, type 2, and type 3 tumors were 11.4 ± 3.29 mm, 19.3 ± 5.44 mm, and 26 ± 3.6 mm, respectively. The CT attenuation increase was 64.5 ± 19 HU on contrast CT. The type 1 tumors were solid (11/11), showed homogeneous or slightly heterogeneous enhancement on CT, and were homogeneously or slightly heterogeneously hypoechoic on sonography. Cystic changes tended to occur in type 2 (7/8) or type 3 (2/3) tumors, which showed obvious heterogeneous attenuation on CT and anechoic on sonography.

CONCLUSIONS

The BCA tends to be small and shows early intense enhancement. The solid tumor is common in the superficial region of the parotid gland, and cystic lesions occur mostly in the deeper parts of the superficial lobe or in the deep lobe.

Preoperative fine needle cytology and imaging facilitates the management of submandibular salivary gland lesions

BACKGROUND

  Lesions of the submandibular gland represent a pleomorphically diverse group in which benign and malignant pathologies are difficult to differentiate from each other. Accurate diagnosis and surgical intervention relies upon clinical presentation, examination and investigations to guide appropriate management. The current series aimed to identify the roles of preoperative cytology and imaging with subsequent histopathology in the management of these lesions.

METHODS

Between 1998 and 2008, 54 patients of median age 54 years (range 25-94), with a male : female ratio of 1:3.5 were identified, of which, 50 patients underwent 52 excisions of the submandibular gland. Demographic data were recorded. The utility of imaging and cytology were analysed, and the accuracy of cytology correlated with histology.

RESULTS

Pathologies of resected specimens were sialadenitis 17 (32%), pleomorphic adenomas nine (17%), calculi eight (15%), lymphoma five (10%), squamous cell carcinoma two (4%), adenoid cystic carcinoma one (2%) and other 10 (20%). Twenty-eight patients (52%) underwent fine-needle aspiration cytology/core biopsies, of which 25 (89%) were correlated with histology. The accuracy, sensitivity and specificity of the fine-needle aspiration cytology correlation with histology were 88.0%, 71.4% and 94.4%, respectively. Overall, the complication rate was 9.6%; involving five temporary nerve palsies of the marginal mandibular branch of the facial nerve, including one temporary lingual nerve palsy.

CONCLUSION

This series demonstrates histological outcomes in patients specific to the submandibular salivary gland. The malignancy rate was low compared to current published literature. The transcervical surgical approach to submandibular gland pathology is a safe and effective method with minimal morbidity when performed by experienced surgeons. No single investigative modality can be solely aligned with diagnosing a specific lesion of the submandibular gland.