Imaging of salivary gland tumours

Foot plantar soft tissue malignant myoepithelioma tumor: Case report and review of the literature

The spectrum of myoepithelial tumors usually occur in the salivary glands, and occasionally in the skin, breast, upper aero-digestive tract, and soft tissues. The myoepithelial tumors have no sex predominance and usually present within a wide range of age of distribution around the third and fifth decades. We describe a 12 year old male patient with primary malignant myoepithelial tumor in the foot plantar soft tissues. Including this tumor with unusual location, and age of presentation is essential in the differential diagnosis for soft tissue tumors in the pediatric population.

Epithelial salivary gland tumors: Utility of radiomics analysis based on diffusion-weighted imaging for differentiation of benign from malignant tumors

OBJECTIVE

To evaluate the utility of radiomics analysis for differentiating benign and malignant epithelial salivary gland tumors on diffusion-weighted imaging (DWI).

METHODS

A retrospective dataset involving 218 and 51 patients with histology-confirmed benign and malignant epithelial salivary gland tumors was used in this study. A total of 396 radiomic features were extracted from the DW images. Analysis of variance (ANOVA) and least-absolute shrinkage and selection operator regression (LASSO) were used to select optimal radiomic features. The selected features were used to build three classification models namely, logistic regression method (LR), support vector machine (SVM), and K-nearest neighbor (KNN) by using a five-fold cross validation strategy on the training dataset. The diagnostic performance of each classification model was quantified by receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) in the training and validation datasets.

RESULTS

Eight most valuable features were selected by LASSO. LR and SVM models yielded optimally diagnostic performance. In the training dataset, LR and SVM yielded AUC values of 0.886 and 0.893 via five-fold cross validation, respectively, while KNN model showed relatively lower AUC (0.796). In the testing dataset, a similar result was found, where AUC values for LR, SVM, and KNN were 0.876, 0.870, and 0.791, respectively.

CONCLUSIONS

Classification models based on optimally selected radiomics features computed from DW images present a promising predictive value in distinguishing benign and malignant epithelial salivary gland tumors and thus have potential to be used for preoperative auxiliary diagnosis.

Gigantic submandibular pleomorphic adenoma: A rare case report

INTRODUCTION

Pleomorphic adenoma (PA) is the most common benign salivary gland tumor. When neglected on some occasions, its size and weight can enormously augment.

CASE PRESENTATION

We report a case of a giant submandibular pleomorphic adenoma in a 75 years old female patient which measured 34 × 26 × 20 cm and weighed 8.1 kg.

CONCLUSION

Neglecting such tumors without treatment, can cause severe facial disfigurement and can even hinder the airway.

A multicentre retrospective clinico-histopathological review of 250 patients after parotidectomy

A clinicopathological review of parotid tumours treated surgically in two oral and maxillofacial surgery departments was conducted. The performance of fine needle aspiration cytology (FNAC) was also assessed. This retrospective study included 250 consecutive patients treated surgically for parotid gland-related tumours. Benign tumours (n=211, 84.4%) were more prevalent than malignancies (n=39, 15.6%). A predominance of pleomorphic adenoma (48.8%) was identified, and epithelial-myoepithelial carcinoma (3.6%) was the most common malignant tumour. Overall, the sensitivity and specificity of FNAC were 64% and 99%, respectively. Subgrouping resulted in sensitivity and specificity of 50% and 100% for clinically assisted FNAC versus, 72% and 99% for ultrasound guidance. Surgically, 31.6% underwent complete superficial parotidectomy and 28.4% underwent extracapsular dissection. Overall, facial nerve palsy was the most prevalent postoperative complication, affecting 29.2% (70/240); loss of function was transient in 21.2% (51/240) and permanent in 7.9% (19/240). Extracapsular dissection and superficial parotidectomy with facial nerve preservation were the treatments of choice when a benign tumour was suspected. Facial nerve palsy was quite frequent; treatment options however are scarce. Preoperative diagnostic workup using imaging and ultrasound-guided FNAC was essential in identifying malignancy so that surgical planning could be adapted.

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.

An Unusual Variant of a Common Palatal Salivary Gland Tumor: Case Report of a Pleomorphic Adenoma with Significant Lipomatous Metaplasia

Introduction

Salivary gland tumors are relatively common in the junction of the hard and soft palate area of the oral cavity. Pleomorphic adenoma is considered the most common benign salivary gland tumor in this location. Some of the rarer subtypes of this tumor may have a misleading clinical presentation. Recognition of these variants is important since long-standing pleomorphic adenomas have the potential to become malignant.

Case Presentation

A healthy 24-year-old male was referred for a painless, large, slowly growing, exophytic swelling of the right hard and soft palate. Interestingly, the lesion was yellowish in color and soft to palpation, suggestive of an innocuous lipoma or cystic lesion. An incisional biopsy was performed and the diagnosis was consistent with pleomorphic adenoma with a significant adipose tissue component. The patient was referred to an oral surgeon and underwent a complete surgical excision. Upon two-year follow-up, the patient is doing well with no recurrences.

Conclusion

This case highlights a rare microscopic variant of pleomorphic adenoma with altered clinical presentation that led to an erroneous clinical diagnosis. The importance of taking a biopsy for definitive diagnosis and appropriate management is reinforced.

Pitfalls in Gallium-68 PSMA PET/CT Interpretation-A Pictorial Review

The novel Gallium-68 prostate-specific membrane antigen (PSMA)-bis [2-hydroxy-5-(carboxyethyl)benzyl] ethylenediamine-diacetic acid positron emission tomography (PET) tracer is increasingly used in the evaluation of prostate cancer, particularly in the detection of recurrent disease. However, PSMA is expressed in nonprostatic tissues, as well as in other pathologic conditions. Here we illustrate such interpretive pitfalls with relevant images that one may encounter while reporting PSMA PET/CT. This study aims to show variation in physiological distribution of PSMA activity and uptake in various benign and neoplastic disorders that may be misinterpreted as prostatic metastatic disease. These pitfalls are illustrated to enhance awareness, aiding a more accurate interpretation of the study. Retrospective database of all (68)Ga PSMA PET/CT was created and reviewed. In total, 1115 PSMA PET/CT studies performed between February 27, 2015, and May 31, 2017, were reviewed. Any unusual uptake of PSMA was documented, described, and followed up. All cases were then subdivided into the following 4 categories: physiological uptake, benign pathological uptake, nonprostatic neoplastic uptake, and miscellaneous uptake. A variety of nonprostatic tissues and lesions, including accessory salivary gland, celiac ganglion, gall bladder, Paget's bone disease, reactive lymph nodes, non–small cell lung cancer, renal cell cancer, and neuroendocrine tumor, were found to show PSMA uptake. PSMA uptake is not prostate-specific and can be taken up physiologically and pathologically in nonprostatic tissue. It is important for reporting physicians to recognize these findings and instigate appropriate investigations when required while avoiding unnecessary procedures in physiological variation.

Review of the Major and Minor Salivary Glands, Part 2: Neoplasms and Tumor-like Lesions

The salivary glands are small structures in the head and neck, but can give rise to a wide variety of benign and malignant pathology. When this occurs, patients may present with palpable swelling, although it is quite common that they are asymptomatic and a salivary gland mass was discovered as an incidental finding on imaging performed for another reason. It is, therefore, critical that radiologists pay careful attention to the salivary glands and have working knowledge of the key differentiating features of the most common neoplastic and nonneoplastic etiologies of salivary gland masses. The purpose of this review is to provide a succinct image-rich article illustrating the various causes of salivary gland masses via an extensive review of the primary literature. In Part 2, we discuss neoplasms and tumor-like lesions of the salivary glands with a key emphasis on specific imaging features of the most common pathologic entities.

Tuberculosis of the parotid lymph nodes: clinical and imaging features

Objectives

To characterize clinical, computed tomography (CT) and magnetic resonance imaging (MRI) features of tuberculosis (TB) of the parotid nodes.

Materials and methods

CT (n=21) and MR (n=7) images, and clinical data from 25 patients with TB of the parotid nodes were retrospectively analyzed by two experienced radiologists who reached consensus.

Results

Younger patients (aged <50 years) accounted for 72%. Eighty percent of patients were asymptomatic, and had no history of TB exposure. According to clinical and imaging findings, 64% and 60% patients were misdiagnosed as having tumors, respectively. A total of 43 lesions were identified. Thirty-eight (88.4%) lesions involved the superficial lobe. Fourteen (56%) cases had multiple lesions. There were four types of changes in the parotid fascia: local thickening (40%, n=10); local rupture with thickened adjacent skin (28%, n=7); focal bulge (20%, n=5); and no changes (12%, n=3). Cervical lymphadenopathy was seen in 14 out of 25 cases (56%). The lesions were contrast-enhanced in four patterns on CT images: homogeneous enhancement (37.1%, n=13), irregular cyst-like enhancement (37.1%, n=13), thick-walled ring enhancement (14.2%, n=5), and garland-like enhancement (11.4%, n=4). On MRI, the signal intensity of lesions was isointense on T1-weighted image, hyperintense on T2-weighted image, markedly hyperintense on diffusion-weighted imaging, and low on the apparent diffusion coefficient map. The surrounding parotid parenchymal edema was identified clearly on coronal MR images.

Conclusion

TB of the parotid nodes tend to simulate tumors clinically and radiologically. Their preferential sites are the superficial lobe. In young patients with positive purified protein derivative skin test and lesions accompanied by cervical lymphadenopathy, changes in the parotid fascia and parotid parenchymal edema adjacent to the lesions on CT and MRI may be helpful in the diagnosis and to facilitate differential diagnosis.

Imaging of Submandibular and Sublingual Salivary Glands

The submandibular and sublingual salivary glands are major salivary glands with a wide spectrum of pathologic conditions. The corresponding spaces along the floor of mouth have complex anatomy, best evaluated with cross-sectional imaging. The spectrum of diseases in these regions varies from simple infection to advanced malignancy, not just from the gland itself but also from the surrounding structures. The most common abnormalities in these spaces are inflammatory and infectious, and computed tomography is currently the most common imaging modality used. The anatomy of these spaces is much better depicted with MR; however, all the modalities have their unique roles.

Chronic atypical first bite syndrome and primary squamous cell carcinoma of the parotid

BACKGROUND

First bite syndrome is a well-recognized complication of parapharyngeal space surgery. There are no reported cases of protracted first bite syndrome and subsequent diagnosis of a primary squamous cell carcinoma (SCC) of the parotid.

METHODS

We present the case of a 73-year-old man with no surgical history and 9 years of first bite syndrome who was ultimately diagnosed with a primary SCC of the parotid. Diagnostic workup, including MRI and biopsy, along with oncologic treatment, were performed.

RESULTS

Surgical treatment confirmed malignancy and also resulted in complete resolution of the first bite syndrome.

CONCLUSION

First bite syndrome without prior surgery may warrant further diagnostic workup with imaging to evaluate for salivary gland pathology. When no radiographic mass lesion is detected but the patient displays protracted symptoms unresponsive to conservative therapy, one should maintain an index of suspicion for malignancy, especially in the presence of symptom escalation.

Contemporary Management of Benign and Malignant Parotid Tumors

To report the standard of care, interesting new findings and controversies about the treatment of parotid tumors. Relevant and actual studies were searched in PubMed and reviewed for diagnostics, treatment and outcome of both benign and malignant tumors. Prospective trials are lacking due to rarity of the disease and high variety of tumor subtypes. The establishment of reliable non-invasive diagnostics tools for the differentiation between benign and malignant tumors is desirable. Prospective studies clarifying the association between different surgical techniques for benign parotid tumors and morbidity are needed. The role of adjuvant or definitive radiotherapy in securing loco-regional control and improving survival in malignant disease is established. Prospective clinical trials addressing the role of chemotherapy/molecular targeted therapy for parotid cancer are needed. An international consensus on the classification of parotid surgery techniques would facilitate the comparison of different trials. Such efforts should lead into a clinical guideline.

Clinical utility of dynamic-enhanced MRI in salivary gland tumors: retrospective study and literature review

PURPOSE

To improve the diagnoses of the salivary gland tumors, a dynamic-enhanced MRI (dMRI) was investigated.

METHODS

We conducted a retrospective chart review of 93 cases of salivary gland tumors. The histological diagnoses were obtained from all patients using a surgical specimen and/or an open biopsy specimen. The dMRI as well as fine-needle aspiration cytology (FNAC) and intraoperative frozen section (IFS) were analyzed. This study focused on the time-intensity curve (TIC) after injection, peak time (Tpeak), washout ratio (WR) as well as the gradient of enhancement and washout profile.

RESULTS

The histological diagnoses included pleomorphic adenoma (PMA) in 53 cases, the Warthin tumors (WT) in 14 cases and malignant tumors (MT) in 26 cases. Incorrect diagnosis rate of FNAC and IFS were 5.2 and 8.3%, respectively. The TIC revealed differences among the three types of tumors. Tpeak as well as WR also revealed significant differences (p < 0.001). Tpeak were lower in order of WT, MT, PMA, respectively. WR of TICs at 30, 45 and 105 s after Tpeak were higher in order of WT, MT, PMA, respectively (p < 0.001). The gradient of increment and washout in the TIC curve was also an important parameter to distinguish the three types of tumors. In MT, the rapid enhancement pattern was found in high or intermediate histological grade tumors, whereas the slow enhancement pattern was exhibited in low grade tumors.

CONCLUSIONS

Our findings indicate that using Tpeak and WR, it is possible to distinguish between WT, PMA and MT. Additionally, a rapid enhancement pattern may be a potential marker for these tumors.

Non-enhanced MRI in combination with color Doppler flow imaging for improving diagnostic accuracy of parotid gland lesions

PURPOSE

To determine the value of non-enhanced MRI in combination with color Doppler flow imaging (CDFI) for differentiating malignant parotid tumors from benign ones.

METHODS

This retrospective study analyzed 51 parotid gland lesions (39 benign and 12 malignant) in 51 patients who underwent preoperative CDFI as well as non-enhanced MRI including T₁-weighted, T₂-weighted, and diffusion-weighted imaging (DWI). Degrees of intratumor vascularity were categorized into four grades basing on CDFI findings. The relationships between the lesion and its adjacent external carotid artery and retromandibular vein were inspected on T₁-weighted and T₂-weighted images. Apparent diffusion coefficient (ADC) values were calculated from diffusion-weighted images, and were used to classify the parotid gland lesions with and without reference to the CDFI findings. The classification results were compared using the McNemar test. Sensitivity, specificity, and accuracy percentages were calculated when the non-enhanced MRI/CDFI findings were used to differentiate benign lesions from malignant ones.

RESULTS

The diagnostic accuracy (96.1 vs 82.4%) was significantly improved when ADCs were used together with CDFI findings for classifying parotid gland lesions compared to when ADCs were used alone. Pleomorphic adenomas had the highest ADCs. The ADC thresholds were 1.425 × 10^-3 mm²/s for differentiating pleomorphic adenomas from carcinomas, 0.999 × 10^-3 mm²/s for differentiating pleomorphic adenomas from other benign lesions, and 0.590 × 10^-3 mm²/s for differentiating benign lesions other than pleomorphic adenomas from lymphomas.

CONCLUSION

Combining CDFI with non-enhanced MRI can improve the diagnostic accuracy of MRI for classifying parotid gland lesions.

Intraoral Pigmented Low-Grade Adenocarcinoma, Not Otherwise Specified: Case Report and Immunohistochemical Study

Salivary adenocarcinoma, not otherwise specified (AdCaNOS) is a rare malignant tumor with potential diagnostic challenge, which mainly affects the parotid glands; however, the minor salivary glands can also be involved by AdCaNOS. This paper reports a case of a 45-year-old Afro-descendant woman complaining of a slow-growing mass with 6 months of evolution in the left superior vestibular fornix. Microscopic examination revealed an infiltrative epithelial neoplasm composed of predominantly solid growth pattern, arranged in a lobular configuration, admixed with glandular or ductal structures. Perineural invasion was evident. The tumor cells were polygonal or oval showing focally mild nuclear pleomorphism, and eosinophilic or clear cytoplasm. Notably, some areas exhibited intracytoplasmic pigment granules mainly in non-luminal cells, as well as sebaceous-like cells, discrete hyaline material deposition and foci of infiltration of residual salivary gland parenchyma. Tumor cells were negative for PAS, mucicarmine and Alcian blue stains. By immunohistochemistry, the tumor cells were diffuse and strongly positive for pan-cytokeratin (CK) AE1/AE3, 34betaE12 CK, vimentin, p63 and S100. CK7 and EMA strongly highlighted the ductal structures. Solid areas also showed diffuse and moderate expression of CD56. Podoplanin (D2-40), GFAP and Calponin, followed by DOG-1, were focally positive; whereas CK20, α-SMA, h-Caldesmon, CD57, ERBB2/HER2 and p53 were negative. Ki-67 was < 2%. Consecutive serial tissue sections using CD57 confirmed the perineural invasion. Positivity for HMB-45 and MART-1/Melan-A, as well as Fontana-Masson stain (and potassium permanganate bleaching-sensitive), identified the pigment granules as melanin. To the best of our knowledge, this is the first case of intraoral low-grade AdCaNOS with intracytoplasmic melanin granules.

Role of diffusion-weighted imaging in head and neck lesions: Pictorial review

Head and neck cancers are very common worldwide, causing significant morbidity and mortality. Squamous cell carcinoma originating from the epithelial lining of the upper aerodigestive tract is the most common histology. Many patients with head and neck cancers present with advanced stage disease requiring aggressive treatment consisting of extensive surgery and chemo-radiation. Appropriate treatment planning as well as prognosis of tumors depends to a large extent on accurate histological diagnosis and differentiation of malignant from benign lesions. Routine imaging modalities such as computed tomography and magnetic resonance imaging give volumetric and morphologic information. However, these modalities cannot be reliably used as a substitute for biopsy in treatment planning. However, diffusion-weighted imaging has shown promise in tissue characterization for primary tumors and nodal metastases, differentiation of recurrent tumor from post therapeutic changes, prediction and monitoring of treatment response, and many other clinical scenarios as described later in this article. In this review article, we describe the imaging findings in applications of diffusion-weighted imaging in the head and neck lesions and discuss their added value over anatomic imaging.

CT features and analysis for misdiagnosis of parotid tuberculosis

PURPOSE

To analyze the computed tomography (CT) features and the reasons for misdiagnosis of parotid tuberculosis (TB).

METHODS

CT features of 13 cases of parotid TB identified more than a 10-year period (2005-2015) were retrospectively analyzed. The CT features were analyzed for nature, range, and extent of the various pathological patterns.

RESULTS

Because of the nonspecific CT features, 10 of 13 cases were misdiagnosed as benign and malignant tumors of parotid gland and received surgery. Ten cases of lymph nodal TB, one case of parenchymal TB, and two cases of mixed (concurrence of lymph nodal and parenchymal types) TB were found in the parotid gland. On contrast-enhanced CT scan, two cases showed homogeneous enhancement and eight cases showed ring enhancement (including five cases with thin-walled ring enhancement, two cases with flower-ring enhancement, and one case with thick-walled and eccentric ring enhancement); diffuse enhancement was seen in the one case of parenchymal type; the two cases of mixed type showed diffuse enhancement of parotid gland and ring enhancement of lymph node. Thickened skin around the parotid gland was seen in eight cases, including sinus tract between the lesion and skin in two cases. Ipsilateral cervical lymphadenopathy was found in 10 patients and bilateral was found in 3 patients.

CONCLUSIONS

Nonspecific CT features of parotid TB closely relate with pathological changes. Recognition and understanding the spectrum of CT features of parotid TB is helpful for differential diagnosis, but the definitive diagnosis still depends on laboratory and pathological examination.

PET/MR in cancers of the head and neck

One early application of PET/MRI in clinical practice may be the imaging of head and neck cancers. This is because the morphologic imaging modalities, CT and MR, are recognized as similarly effective tools in cross-sectional oncological imaging of the head and neck. The addition of PET with FDG is believed to enhance the accuracy of both modalities to a similar degree. However, there are a few specific scenarios in head and neck cancer imaging where MR is thought to provide an edge over CT, including perineural spread of tumors and the infiltration of important anatomical landmarks, such as the prevertebral fascia and great vessel walls. Here, hybrid PET/MR might provide higher diagnostic certainty than PET/CT or a separate acquisition of PET/CT and MR. Another advantage of MR is the availability of several functional techniques. Although some of them might enhance the imaging of head and neck cancer with PET/MR, other functional techniques actually might prove dispensable in the presence of PET. In this overview, we discuss current trends and potential clinical applications of PET/MR in the imaging of head and neck cancers, including clinical protocols. We also discuss potential benefits of implementing functional MR techniques into hybrid PET/MRI of head and neck cancers.

Dynamic Contrast Magnetic Resonance Imaging (DCE-MRI) and Diffusion Weighted MR Imaging (DWI) for Differentiation between Benign and Malignant Salivary Gland Tumors

BACKGROUND

Salivary gland tumors form nearly 3% of head and neck tumors. Due to their large histological variety and vicinity to facial nerves, pre-operative diagnosis and differentiation of benign and malignant parotid tumors are a major challenge for radiologists.

OBJECTIVE

The majority of these tumors are benign; however, sometimes they tend to transform into a malignant form. Functional MRI techniques, namely dynamic contrast enhanced (DCE-) MRI and diffusion-weighted MRI (DWI) can indicate the characteristics of tumor tissue.

METHODS

DCE-MRI analysis is based on the parameters of time intensity curve (TIC) before and after contrast agent injection. This method has the potential to identify the angiogenesis of tumors. DWI analysis is performed according to diffusion of water molecules in a tissue for determination of the cellularity of tumors.

CONCLUSION

According to the literature, these methods cannot be used individually to differentiate benign from malignant salivary gland tumors. An effective approach could be to combine the aforementioned methods to increase the accuracy of discrimination between different tumor types. The main objective of this study is to explore the application of DCE-MRI and DWI for assessment of salivary gland tumor types.

Benign metastasizing pleomorphic adenoma in liver mimicking synchronic metastatic disease from colorectal cancer: a case report with emphasis on imaging findings

Pleomorphic adenoma of the parotid gland with metastases to the liver is a rare etiology of focal liver lesions, and there are no described pathognomonic imaging features. We report a patient who presented with a newly diagnosed rectal cancer and multiple cystic liver lesions suspicious of mucinous synchronous liver metastases. Following chemotherapy no reduction in the number or size of the liver lesions was observed. The patient was re-evaluated and a biopsy of a lesion was performed. The specimen showed a metastasis from a pleomorphic adenoma of the parotid gland for which the patient had been treated 20 years earlier. The case illustrates how a thorough medical history can be crucial when a standard diagnostic imaging workup for colorectal cancer metastases is uncertain, and how a biopsy, though regarded as contraindicated due to the risk of tumor cell dissemination, can be required to secure a correct diagnosis.

Genetic polymorphisms in UDP-glucuronosyltransferase 1A6 and 1A7 and the risk for benign Warthin's tumors of the parotid gland

BACKGROUND

Warthin's tumors of the parotid gland are associated with smoking, whereas pleomorphic adenomas are not. Genetic polymorphisms in biotransformation enzymes, involved in detoxification of toxins and carcinogens in cigarette smoke, might modify the corresponding enzyme activity and influence detoxifying capacity. We hypothesize that these genetic polymorphisms may influence the individual risk for Warthin's tumor, but not for pleomorphic adenomas.

METHODS

Blood from 146 patients with benign parotid gland tumors and 437 controls were investigated for polymorphisms in several biotransformation enzymes. Based on these polymorphisms, patients and controls were divided according to predicted enzyme activity (low, intermediate, and high).

RESULTS

Prevalence of predicted intermediate and high activity UGT1A7 and UGT1A6 genotypes was significantly higher in the patients with Warthin's tumors, but not in patients with pleomorphic adenomas, compared with healthy controls.

CONCLUSION

Predicted intermediate and high activity UGT1A7 and UGT1A6 genotypes are associated with an increased risk for Warthin's tumor. © 2015 Wiley Periodicals, Inc. Head Neck 38: E717-E723, 2016.

Differentiating benign and malignant salivary gland tumours: diagnostic criteria and the accuracy of dynamic contrast-enhanced MRI with high temporal resolution

OBJECTIVE

To determine the optimal diagnostic criterion of dynamic contrast-enhanced MRI (DCE-MRI) for predicting salivary gland malignancy using a dynamic sequence with high temporal resolution, as well as the accuracy of this technique.

METHODS

The DCE-MRI findings of 98 salivary gland tumours (74 benign and 24 malignant) were reviewed. MR images were sequentially obtained at 5-s intervals for 370 s. Two parameters, peak time and washout ratio (WR) were determined from the time-signal intensity curve. The optimal thresholds of these parameters for differentiating benign and malignant tumours were determined, along with the diagnostic accuracy of the criterion using these thresholds.

RESULTS

A peak time of 150 s and a WR of 30% were identified as optimal thresholds. As the criterion for malignancy, the combination of peak time <150 s and WR <30% provided a sensitivity of 79% (19/24), specificity of 95% (70/74) and an overall accuracy of 91% (89/98). Three of the five false-negative cases were malignant lymphomas of the parotid gland.

CONCLUSION

Peak time <150 s with WR <30% comprised the optimal diagnostic criterion in predicting salivary gland malignancy, providing a sensitivity of 79% and specificity of 95%. The use of high temporal resolution might improve the accuracy of DCE-MRI.

ADVANCES IN KNOWLEDGE

Although several studies have reported the usefulness of DCE-MRI in the differential diagnosis of salivary gland tumours, the specific diagnostic criteria employed have differed widely. We determined the optimal criterion and its accuracy using a dynamic sequence with high temporal resolution.

Label-free determination of lipid composition and secondary protein structure of human salivary noncancerous and cancerous tissues by Raman microspectroscopy

The applications of optical spectroscopic methods in cancer detection open new possibilities in oncological diagnostics.

The role of diffusion-weighted magnetic resonance imaging in the diagnosis, lymph node staging and assessment of treatment response of head and neck cancer

Standard magnetic resonance imaging (MRI) and computed tomography continue to be the imaging modalities of choice in staging and reviewing patients with head and neck cancer. Diffusion-weighted MRI (DW-MRI) is an advanced imaging modality that records the molecular diffusion of protons and thus provides an opportunity to further assess tissue character. Interest in DW-MRI of the head and neck continues to grow, especially its application to the assessment and treatment of head and neck cancer. We highlight the potential role of DW-MRI in the delineation, characterization, and lymph node staging of head and neck tumours. Furthermore, we discuss the ability of DW-MRI to provide a real opportunity to differentiate post-treatment tumour recurrence from chemoradiotherapy-induced local tissue changes. The future impact of these findings upon the clinical practice of the head and neck surgeon is discussed.

Lymphoepithelial carcinoma of the salivary gland: morphologic patterns and imaging features on CT and MRI

BACKGROUND AND PURPOSE

Lymphoepithelial carcinoma is a rare salivary gland lesion. We retrospectively reviewed CT and MR imaging features of salivary gland lymphoepithelial carcinoma to determine their imaging features and morphologic patterns.

MATERIALS AND METHODS

The clinical data, CT, and MR imaging findings of 28 patients with histologically proved lymphoepithelial carcinoma of the salivary gland were retrospectively reviewed. Morphologic patterns of the lesions were categorized into 3 types on the basis of margin and shape.

RESULTS

There were 17 men and 11 women with a mean age of 39.3 years; 96.4% of patients were positive for Epstein-Barr virus both on histologic staining and Epstein-Barr virus serology. Tumors were parotid in 18 patients, submandibular in 8 patients, sublingual in 1 patient, and palatal in 1 patient. Most tumors (57.1%) manifested as a partially or ill-defined mass with a lobulated or plaque-like shape. Homogeneous enhancement was found in 16 patients, while heterogeneous enhancement was found in 12, including 4 patients with intratumoral necrosis. Invasion into adjacent structures was found in 5 patients; 60.7% of patients exhibited abnormal lymph nodes, with nodal necrosis in 3 patients.

CONCLUSIONS

The characteristic lobulated or plaque-like shape, with a partially or ill-defined margin, of a salivary gland mass associated with ipsilateral lymphadenopathy may suggest a preoperative diagnosis of lymphoepithelial carcinoma.

Assessment of the role of cone beam computed sialography in diagnosing salivary gland lesions

Purpose

The purpose of this study was to assess cone-beam computed (CBCT) sialography imaging in the detection of different changes associated with lesions of salivary glands.

Materials and Methods

This study consisted of 8 cases with signs and symptoms from salivary gland lesions. Conventional sialography using digital panoramic and lateral oblique radiographs and CBCT sialography were performed for each subject. The radiographs were evaluated by 3 radiologists independently of each other. The results were compared between conventional sialography and CBCT sialography in the evaluation of various lesions associated with the salivary glands.

Results

There was an agreement between the radiologists in interpreting the lesions that affected salivary glands with both techniques. The detection of the presence of stones or filling defects, stenosis, ductal evagination, dilatation, and space occupying lesions was 83% for conventional sialography compared with CBCT sialography. CBCT sialography was superior to conventional sialography in revealing stones, stenosis, and strictures, especially in the second and third order branches.

Conclusion

It would be advisable to perform CBCT sialography in cases of obstructive salivary gland diseases for better demonstration of the ductal system of the gland.

Sonoelastography techniques in the evaluation and diagnosis of parotid neoplasms

Ultrasound is the first-line imaging investigation in the evaluation of parotid gland lesions; however, ultrasound alone cannot differentiate between benign and malignant lesions. An imaging technique with this capability would be of great value, as fine needle aspiration cytology (FNAC) is not always accurate and partial/total parotidectomy is associated with facial nerve palsy and Frey's syndrome. Sonoelastography is a novel imaging technique that has been employed in the research setting in the evaluation of tissues including breast, thyroid, prostate and the salivary glands. More recently it has been used as a diagnostic adjunct in the sonographic evaluation of major salivary gland lesions. This review article outlines the current role of sonoelastography in the diagnostic imaging of parotid lesions, with particular reference to the findings of two research papers published in European Radiology. These papers employ slightly different techniques: the first utilises shear wave elastography whilst the second uses real-time sonoelastography. Sonoelastography may have potential as a diagnostic imaging adjunct to conventional ultrasound. However, it seems likely that FNAC/core biopsy will continue to be necessary. Further studies to evaluate the reproducibility of sonoelastographic results across a range of operators and systems are also needed. Key Points • Ultrasound is the initial and often definitive investigation for parotid lesions • Ultrasound-based strain elastography has been attempted but offered little additional information • New shear wave elastographic techniques did not confer much advantage either • However, analysis of elastographic patterns seems to provide advantages over ultrasound alone.

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.

MR imaging of parotid tumors: typical lesion characteristics in MR imaging improve discrimination between benign and malignant disease

BACKGROUND AND PURPOSE

The surgical approach to parotid tumors is different for benign and malignant neoplasms, but the clinical symptoms do not correlate well with histology. Difficulties in tumor classification also arise in imaging modalities, in which sonography has the lowest and MR imaging, the highest accuracy. The purpose of this study was to review our experience using conventional MR imaging of the neck in the evaluation of parotid tumors and to evaluate which MR imaging findings are best able to predict malignant histology.

MATERIALS AND METHODS

Eighty-four consecutive patients (43 males, 41 females; median age, 56 years; range, 9-85 years) with parotid gland tumors who underwent MR imaging before surgery were prospectively included in the present study and retrospectively analyzed. Histology was available for all tumors. We analyzed the following MR imaging parameters: signal intensity, contrast enhancement, lesion margins (well-defined versus ill-defined), lesion location (deep/superficial lobe), growth pattern (focal, multifocal, or diffuse), and extension into neighboring structures, perineural spread, and lymphadenopathy.

RESULTS

The 57 (68%) benign and 27 (32%) malignant tumors consisted of 29 pleomorphic adenomas, 17 Warthin tumors, 11 various benign tumors, 5 mucoepidermoid carcinomas, 3 adenoid cystic carcinomas, 1 acinic cell carcinoma, 1 carcinoma ex pleomorphic adenoma, 9 metastases, and 8 various malignant neoplasms. Specific signs predictive of malignancy were the following: T2 hypointensity of the parotid tumor (P = .048), ill-defined margins (P = .001), diffuse growth (P = .012), infiltration of subcutaneous tissue (P = .0034), and lymphadenopathy (P = .012).

CONCLUSIONS

Low signal intensity on T2-weighted images and postcontrast ill-defined margins of a parotid tumor are highly suggestive of malignancy.

Diffusion-weighted MRI in head and neck radiology: applications in oncology

Extracranial application of diffusion-weighted magnetic resonance imaging (MRI) has gained increasing importance in recent years. As a result of technical advances, this new non-invasive functional technique has also been applied in head and neck radiology for several clinical indications. In cancer imaging, diffusion-weighted MRI can be performed for tumour detection and characterization, monitoring of treatment response as well as the differentiation of recurrence and post-therapeutic changes after radiotherapy. Even for lymph node staging promising results have been reported recently. This review article provides overview of potential applications of diffusion-weighted MRI in head and neck with the main focus on its applications in oncology.