Comparison of Computed Tomography and Magnetic Resonance Imaging in the Diagnosis of Parotid Tumors

Point‐of‐care ultrasound scan as the primary modality for evaluating parotid tumors

Objectives

This study aimed to explore ultrasonography as a single imaging modality for the initial assessment of parotid lesions compared to computed tomography (CT) and magnetic resonance imaging (MRI).

Methods

A retrospective cross‐sectional study was performed on 264 parotid gland lesions evaluated in a dedicated point‐of‐care ultrasound (POCUS) clinic with concurrent fine needle biopsy (FNB). Two hundred and nine of these lesions also underwent CT or MRI imaging. Histopathology results, when available, were recorded and compared to imaging impressions.

Results

Surgeon‐performed POCUS classified parotid masses accurately when compared to final histopathology (90/96, 94%). Using predefined criteria, POCUS determined the nature of parotid lesions more definitively than the descriptive CT or MRI radiology reports (p <.001). Sub‐analysis showed that ultrasonography was able to distinguish between benign pathologies with high degree of accuracy (Warthin tumor—82%, pleomorphic adenoma—64%).

Conclusions

POCUS can accurately distinguish between benign and malignant parotid lesions. POCUS may suffice as the only imaging study for benign lesions, obviating the need for additional cross‐sectional imaging. This can be combined with fine needle or core biopsy in the same visit, resulting in expedient diagnosis, low cost, and lack of radiation exposure.

Level of Evidence

2b, individual cross‐sectional cohort study.

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.

A Primary Parotid Mucosa-Associated Lymphoid Tissue Non-Hodgkin Lymphoma in a Patient With Sjogren Syndrome

The salivary gland tumors are rare entities and the majority of these are benign. However, there are some entities such as prior neck radiation, certain infections, and systemic diseases which should raise the clinical suspicion for a malignant lesion. Patients with Sjogren syndrome are at increased risk for a salivary gland neoplasm, specifically non-Hodgkin lymphoma. While clinical findings play an important role in the initial workup, imaging plays a critical role in the diagnosis and management. This case describes a patient with Sjogren syndrome who presented with a left face mass where imaging was able to confidently diagnose her with a suspicious parotid neoplasm with lymphoma as the favored diagnosis. After histological evaluation, she was diagnosed with primary parotid mucosa-associated lymphoid tissue (MALT) non-Hodgkin lymphoma after which she went on to non-operative management.

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.

Radiomics-based comparison of MRI and CT for differentiating pleomorphic adenomas and Warthin tumors of the parotid gland: a retrospective study

OBJECTIVE

The objective of this study was to compare the diagnostic performance of magnetic resonance imaging (MRI) and computed tomography (CT) in differentiating pleomorphic adenomas from Warthin tumors using radiomics.

STUDY DESIGN

We retrospectively reviewed 626 patients who underwent preoperative MRI or CT for parotid tumor diagnosis. Patient groups were balanced by propensity score matching (PSM) and 123 radiomic features were extracted from tumor images. Radiomic signatures (rad-scores) were generated using a least absolute shrinkage and selection operator logistic regression model. The Canny edge detector was used to define tumor borders (border index). The diagnostic performance of rad-score and border index before and after PSM was evaluated with area under the receiver operating characteristic curve analysis.

RESULTS

For differentiation of pleomorphic adenomas and Warthin tumors, rad-score and border index areas under the curve for MRI after PSM were 0.911 (95% confidence interval [CI], 0.871-0.951) and 0.716 (95% CI, 0.646-0.787), respectively; those for CT were 0.876 (95% CI, 0.829-0.923) and 0.608 (95% CI, 0.527-0.690), respectively. Tumor border index on MRI, but not CT, had superior diagnostic performance (P < .05); MRI- and CT-based rad-scores showed similar performance (P >.05).

CONCLUSIONS

MRI is superior to CT for tumor margin examination; however, the radiomics features of both modalities showed no difference.

Can the height of the parotid tumor be a predictor of malignancy?

Background

Accurate diagnosis of malignancy in the parotid gland before surgery is often challenging. Various clues should be used to increase the index of suspicion for malignancy. We hypothesized that malignant lesions of the parotid gland are located at the superior part of the gland compared to benign ones.

Methods

A total of 169 consecutive patients were included in this study whose medical records were retrospectively reviewed. Benign and malignant tumors were compared in size, height difference from five anatomical landmarks: hard palate, mastoid tip, earlobe, condylar head, and mandibular notch. The cutoff heights from significant landmarks (hard palate, condylar head) were estimated with ROC analysis and chi-square test.

Results

Twenty-nine patients (17.2%) were diagnosed with malignant and 140 patients (82.8%) as benign. The height differed significantly between benign and malignant tumors when the reference point was set for the hard palate (P=0.024) and the condylar head (P=0.049), with the cutoff height from reference points to be 22.5, 51.5 mm, respectively. Diagnostic values of parotid level difference presented higher sensitivity (75.9% for hard palate, 72.4% for condylar head vs. 47.8% for fine needle aspiration cytology) and lower false negative rate (24.1% for hard palate, 27.6% for condylar head vs. 52.2% for fine needle aspiration cytology) compared to fine needle aspiration cytology.

Conclusions

Malignant tumors of the parotid gland tend to locate at the superior part of the gland compared to benign tumors. Parotid tumors lying cephalad should raise an index of suspicion for malignancy. Height of the tumor in the parotid gland should be deliberately considered during the first encounter of the patient, which in turn could curate the next step in the diagnostic approach and treatment planning.

Parotid gland tumors: comparison of conventional and diffusion-weighted MRI findings with histopathological results

OBJECTIVES

The aim of this study was to investigate the relationship between pathological classification of parotid gland tumors and conventional MRI - diffusion-weighted imaging findings and also contribute the possible effect of apparent diffusion coefficient (ADC) to diagnosis.

METHODS

60 patients with parotid masses diagnosed using histopathology and/or cytology were enrolled in this retrospective study. All patients were evaluated using a 1.5 T MRI. Demographic features, conventional MRI findings, and ADC values (mean, minimum, maximum, and relative) were recorded. MRI findings and ADC values were compared between benign-malignant groups and pleomorphic adenoma vs Warthin's tumor groups.

RESULTS

60 tumors (48 benign, 12 malignant) were evaluated in a total of 60 patients (39 males, 21 females). The mean age was 59 (±14, 18-86) years old; the mean lesion size was 26 (±10, 11-61) mm. On the texture of conventional MRI, T2 dominantly hyperintense/with hypointensity signal was seen in 87% of pleomorphic adenomas and T2 dominantly hypointense/with hyperintesity signal was encountered in 64% of all Warthin's tumors. Seven (28%) Warthin's tumors were misdiagnosed as pleomorphic adenomas and two others (8%) as malignant tumors. The commonly used mean ADC value was 1.6 ± 0.6 × 10^-3 mm² s^-1 for benign tumors, 0.8 ± 0.3 × 10^-3 mm² s^-1 for malign tumors, 1 (0.9-1.8) × 10^-3 mm² s^-1 for Warthin's tumors, and 1.9 ± 0.3 × 10^-3 mm² s^-1 for pleomorphic adenomas. There was a statistically significant difference in ADC values between benign-malignant tumors and pleomorphic adenomas-Warthin's tumors.

CONCLUSIONS

Warthin's tumor may occasionally be misdiagnosed as pleomorphic adenoma and malignant tumor because of variable morphologic features. In addition to benign-malignant differentiation, the added ADC measurement may also be useful for differentiating Warthin's tumors from pleomorphic adenomas.

Conventional and Diffusion-Weighted MR Imaging Findings of Parotid Gland Tumors

OBJECTIVE

To investigate diffusion-weighted magnetic resonance imaging (MRI) findings of parotid gland lesions in addition to conventional MRI findings and demographic data.

METHODS

A retrospective evaluation was made of the demographic data, histopathologic data, preoperative conventional and diffusion-weighted MRI of 74 patients who underwent parotidectomy. The patients were categorized according to the histopathology (pleomorphic adenoma [PA], Warthin's Tumor [WT] and malignant Tumor [MT]).

RESULTS

Histologically, 30 patients had PA, 27 patients had WT, and the remaining 17 patients had MT. The mean age of the PA, WT and MT groups were 44±21 (20-72), 55±10 (41-71) and 62±20 (21-76) years, respectively. The WT (81%) and MT (70%) groups were male dominant, while the PA group showed female dominance (55%). The PA group showed statistically significant difference in terms of age (p<0.05) and gender (p=0.009) compared to the other two groups. The median apparent diffusion coefficient (ADC) values for the PA, WT and MT groups were 1.99±0.94 (1.10-2.41) × 10-3 mm2/s, 0.92±0.35 (0.21-1.79) × 10-3 mm2/s and 1.20±0.34 (0.78-1.47) × 10-3 mm2/s, respectively. PA was differentiated from the other two groups (p=0.001). The sensitivity and specificity for distinguishing PAs from WT was 97% and 85%, respectively, when the ADC cutoff value was 1.25; and for distinguishing PAs from MT was 77% and 83%, respectively, when the ADC cutoff value was 1.35.

CONCLUSION

ADC measurements are useful for the differentiation of PA from both WT and MT; and can be used as a complementary tool to predict the histopathology in the preoperative planning of parotid tumors.

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

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

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.

Malignant lymphoma on parotid gland: a clinical case

Non-Hodgkin's lymphoma on the parotid gland is a relatively rare occurrence among head and neck tumors. The mass of parotid gland lymphoma cannot be distinguished from other benign masses of the parotid gland; therefore, it is important to consider lymphoma in the differential diagnosis when examining parotid swellings and masses. Parotid gland lymphoma is most likely to be B-cell, non-Hodgkin's lymphoma of one of three types, which include follicular, marginal zone, and diffuse large B-cell, although other histologic patterns have been described. We present a review of a patient with diffuse large B-cell lymphoma (DLBCL) who presented to the Department of Oral and Maxillofacial Surgery of Pusan National University Hospital (Yangsan, Korea).

Differentiation of pleomorphic adenoma and Warthin's tumor of the parotid gland: ultrasonographic features

BACKGROUND

Parotid tumor is an uncommon neoplasm. Only a few studies describing the sonographic features of pleomorphic adenomas and Warthin's tumors have been published, and most of those reports are based on a relatively small number of cases.

PURPOSE

To define the sonographic characteristics of pleomorphic adenoma and Warthin's tumor in the parotid gland.

MATERIAL AND METHODS

We retrospectively evaluated the sonographic features of 77 pleomorphic adenomas in 70 patients and 93 Warthin's tumors in 61 patients. The features included tumor size, shape, border, echogenicity, and homogeneity, the presence of a cystic area, acoustic enhancement, and the grade and distribution of vascularization.

RESULTS

Lobulated lesions were observed in 49 pleomorphic adenomas and 36 Warthin's tumors. The lobulated shape was observed more frequently in pleomorphic adenomas than in Warthin's tumors (P = 0.005). Cystic areas within lesions were detected in 16 (16/77, 20.8%) pleomorphic adenomas and 42 (42/93, 45.2%) Warthin's tumors (P = 0.001). Of the pleomorphic adenomas, 77.9% had grade 0 or grade 1 vascularity, while 73.1% of Warthin's tumors had grade 2 or grade 3 vascularity (P = 0.000). Flow was peripheral in 53.2% of pleomorphic adenomas. The frequencies of central perfusion and mixed perfusion in Warthin's tumors were equal (47.3% vs. 47.3%, respectively). The differences in the vessel distribution between these two diseases was significant (P = 0.000).

CONCLUSION

Ultrasound imaging characteristics, including multiple occurrences, shape, intrinsic cystic change, and the grade and distribution of tumor vessels, can be used to differentiate pleomorphic adenomas from Warthin's tumors.

[Salivary gland tumors, clinico-epidemiological study and radioanatomy correlation: retrospective study of 148 cases]

Les tumeurs des glandes salivaires sont rares, elles représentent moins de 3% de l'ensemble des tumeurs. Les tumeurs bénignes sont les plus fréquentes dominées par l'adénome pléomorphe, la glande parotide reste la localisation la plus commune. L'objectif de ce travail est d’évaluer la contribution des 3 méthodes d'imagerie: échographie, TDM et IRM dans la différentiation entre tumeur maligne et lésion bénigne. C'est une étude rétrospective à propos de 148 cas de tumeurs des glandes salivaires collectés sur 5 ans. Les paramètres étudiés étaient l’âge, le sexe du patient, le motif de consultation, les données de l'examen clinique, les données de l'imagerie. Chacun des critères radiologiques utilisés pour déterminer la nature de la tumeur a été analysée et corrélé avec les données de l'histologie. L'analyse s'est basée sur le test du X2 et le calcul du p. Nous avons calculé la sensibilité, la spécificité et l'efficacité diagnostique pour chaque modalité. La localisation parotidienne était prédominante (80%), les tumeurs bénignes ont représenté 76%, dominés par l'adénome pléomorphe. L’échographie a révélé que seulement la présence de quelques critères prédisent le caractère malin de la masse: les limites floues, irrégulières, et la présence d'adénopathies (p < 0,05). A la TDM, seules les limites floues de la masse et l'extension aux tissus adjacents étaient des indicateurs de malignité. A l'IRM, l'irrégularité des contours, l'hyposignal et le signal intermédiaire en séquences T1 et T2, et l'extension aux tissus avoisinants étaient en faveur de la malignité. La corrélation entre résultats de l'imagerie et diagnostic histologique a révélé la supériorité de l'IRM par rapport au scanner et à l’échographie, en termes de sensibilité, spécificité et efficacité diagnostique. L’évaluation préopératoire des tumeurs des glandes salivaires est devenue un challenge pour les ORL et les radiologues, pour prédire la nature de la lésion. L'IRM représente l'examen de choix, notamment avec l'apparition des nouvelles techniques dynamiques.

Acquired von Willebrand's disease associated with epithelial myoepithelial carcinoma of the parotid salivary gland

This is the first case report of a patient with acquired von Willebrand's disease (AvWD) secondary to epithelial myoepithelial carcinoma (EMC) of the parotid salivary gland. This patient presented to haematology following an abnormal bleeding episode with von Willebrand factor Ristocetin cofactor (VWF:RCo) <5% and VWF:Ag 13%. He was diagnosed with AvWD. At the same time he was found to have a left parotid lump which was excised following a multidisciplinary team meeting. This was histologically reported as an EMC. Following excision, unusually this patient's AvWD did not resolve. Extensive investigation looking for other causes of the AvWD did not reveal any other potential cause; therefore, due to the similar timing of onset of both pathologies it is felt that the AvWD in this case is secondary to the EMC. This case report highlights the presentation, investigation and management of AvWD and parotid lumps as well as discussing proposed pathophysiological mechanisms for AvWD.

Parotid lymphoma: a review of clinical presentation and management

Lymphoma of the parotid gland is a relatively rare occurrence among head and neck tumors. Presentation is indistinguishable from other swellings of the parotid gland; therefore, it is important to consider lymphoma in the differential diagnosis when examining parotid swellings. Parotid lymphomas are most likely to be B-cell non-Hodgkin lymphoma of 1 of 3 types, which include follicular, marginal zone, and diffuse large B cell, although other histologic patterns have been described. We present a review of 3 patients with parotid lymphoma who presented to the University of Maryland Medical Center's Department of Oral and Maxillofacial Surgery with facial swelling. Two patients were diagnosed with follicular lymphoma, whereas the third was diagnosed with marginal zone lymphoma.

Bilateral multifocal Warthin tumours

Warthin tumour, also known as papillary cystadenoma lymphomatosum, is the second most frequent benign tumour of the parotid gland after pleomorphic adenoma. A 57-year-old man was referred to our hospital with bilateral buccal masses without pain. He presented with a 1-year history of the condition and stated that growth of the mass has accelerated during the last 6 months. Ultrasonography examination showed two heterogeneous solid masses. Axial contrast-enhanced CT image revealed bilateral heterogeneous solid masses. The masses showed enhancement after contrast administration (95 HU). Fine needle aspiration cytology was recommended for further analysis and typical benign features of Warthin tumour was obtained. Right parotid gland including the masses was resected completely. 5 weeks later superficial parotidectomy was performed to the left parotid gland. Histological examination revealed cystic tumour in the parenchyma of parotid gland, composed of prominent lymphoid stroma and large epithelial cells with oncocytic features covering it consistent with Warthin tumour.

Diagnosis and treatment outcomes for patients with lymphoma of the parotid gland

OBJECTIVES/HYPOTHESIS

Lymphoma of the parotid gland (LPG) is a rare disease. Clinical diagnosis is difficult, due to a lack of specific symptoms and findings. The aim of this study is to evaluate the diagnostic workup based on the analysis of our cases of LPG and to present the stage-dependent treatment outcome.

STUDY DESIGN

Retrospective case-control study.

METHODS

From 1992 to 2008, 697 patients at our institution underwent surgery because of a parotid tumor. Among 246 malignancies, an LPG was found histologically in 28 cases (4%). Staging was performed according to the Ann Arbor classification, and treatment was performed by radiotherapy and/or chemo/immunotherapy. The patients were retrospectively analyzed.

RESULTS

No specific symptoms were found, with the main finding being a unilateral, painless, slowly progressing parotid mass. The sensitivities of imaging and fine-needle aspiration cytology in detecting LPG were 41% and 12%, respectively. Histology was the key to diagnosis, and frozen sections often revealed the diagnosis during surgery, which obviated the need for more extensive surgery in 89% of cases. The 5-year disease-specific survival estimates were 100% and 75% for early tumor stages (I and II) and advanced stages (III and IV), respectively.

CONCLUSIONS

When the precise nature of a parotid mass remains obscure after fine-needle aspiration cytology and imaging, but LPG is clinically suspected, surgical tissue sampling with frozen sections appears to be a valid option and can prevent the need for more extensive surgery. The treatment outcome for LPG is favorable.

Pleomorphic adenoma of parotid gland: delayed enhancement on computed tomography

OBJECTIVES

To assess the efficacy of multiphasic CT with 8 min delayed acquisition in the differential diagnosis between pleomorphic adenomas and other parotid neoplasias.

METHODS

Between January 2004 and April 2007, 62 patients with parotid enlargement were enrolled in this prospective study. The CT protocol applied included the following four acquisitions: without contrast medium and 30 s, 120 s and 8 min after intravenous injection of contrast medium. We considered the degree of the enhancement of the lesions (rated as "low", "moderate" and "strong") and the degree of enhancement homogeneity (rated as "not homogeneous", "mildly homogeneous" and "uniform"). These parameters were compared with Hounsfield values of the lesions computed in each phase. The diagnosis was confirmed in all patients after surgery.

RESULTS

On histological examination, 36 tumours were classified as pleomorphic adenomas and 26 as non-pleomorphic adenomas. On the basis of a statistical comparison, the third phase proved to be the most effective in the differential diagnosis between pleomorphic adenoma and non-pleomorphic adenomas, both for the assessment of the degree of the enhancement (in this phase, strong enhancement showed a sensitivity of 61.11%, specificity of 100%, positive predictive value (PPV) of 100% and negative predictive value (NPV) of 53.33%) and, above all, for the homogeneity of the enhancement (in this phase, indeed, uniform enhancement showed sensitivity, specificity, PPV and NPV of 100%).

CONCLUSIONS

Our results seem to indicate that multiphasic CT with 8 min delayed acquisition allows the differential diagnosis between pleomorphic adenomas and other parotid neoplasias.

Evaluation of clinician-operated sonography and fine-needle aspiration in the assessment of salivary gland tumours

OBJECTIVES

To evaluate the combination of ultrasound (US) + fine-needle aspiration (FNA) in the assessment of salivary gland tumours in the hands of the otolaryngologist.

DESIGN

A retrospective review of case notes was performed.

SETTING

Two university teaching hospitals in Switzerland.

PARTICIPANTS

One hundred and three patients with a total of 106 focal masses of the salivary glands were included. Clinician-operated US + FNA were the first line of investigation for these lesions. All patients underwent surgical excision of the lesion, which allowed for confirmation of diagnosis by histopathology in 104 lesions and by laboratory testing in two lesions.

MAIN OUTCOME MEASURES

Primary--diagnostic accuracy in identifying true salivary gland neoplasms and detecting malignancy. Secondary--predicting an approximate and specific diagnosis in these tumours.

RESULTS

The combination of US + FNA achieved a diagnostic accuracy of 99% in identifying and differentiating true salivary gland neoplasms from tumour-like lesions. In detecting malignancy, this combination permitted an accuracy of 98%. An approximate diagnosis was possible in 89%, and a specific diagnosis in 69% of our patients.

CONCLUSIONS

Due to economic factors and a high diagnostic accuracy, the combination of US + FNA represents the investigation method of choice for most salivary gland tumours. We suggest that the otolaryngologist be employed in carrying out these procedures, as is already the rule in other medical specialties, while computed tomography and magnetic resonance imaging should be reserved to those few lesions, which cannot be delineated completely by sonography.

The value of dynamic MRI studies in parotid tumors

RATIONALE AND OBJECTIVES

To evaluate the ability of dynamic contrast-enhanced magnetic resonance imaging (MRI) to differentiate several tumor entities of the parotid gland in a prospective clinical trial.

MATERIALS AND METHODS

A total of 112 patients with parotid tumors were examined with dynamic contrast-enhanced 1.5 T MRI. Precontrast axial T1-weighted imaging was used to select five slices for the dynamic study. Subsequently, a T1-weighted FLASH sequence was used for the dynamic contrast study (0.2 ml Gd/kg x body weight). Contrast agent application and the FLASH sequence were started simultaneously. Ten acquisitions of 10 seconds' scan time each were performed (total acquisition time 1:40 minutes). Signal intensity versus time (SIvT) curves was obtained for all tumors. After correlation of the categorized SIvT curves, these were compared with histopathology. Finally, all MRIs together with the tumor specific SIvT curves were re-read and correlated with histopathologic diagnosis. All reading sessions were done by three experienced radiologists.

RESULTS

Four characteristic intensity-time curves were observed: pleomorphic adenoma showed a gradual increase in signal intensity, followed by a plateau phase on a low intensity level. Cysts showed a vacillating course at a low signal intensity level. Adenolymphomas as well as carcinomas showed a rapid increase in signal intensity followed by a plateau phase. Statistic significance was found for the time-to-peak values for adenolymphomas and pleomorphic adenomas and for the maximum peak signal intensity values for carcinomas. Together with other morphologic MRI criteria (contrast enhancement, border characteristics) and clinical features, a differentiation between adenolymphoma and carcinoma was possible.

CONCLUSIONS

With additional dynamic contrast-enhanced MRI, a more reliable differentiation between common parotid tumors is possible before surgery.

Dynamic multislice computed tomography findings for parotid gland tumors

OBJECTIVE

Our aim was to research the enhancement features of parotid gland masses in detail and characterize if the masses were Warthin tumors, adenomas, or malignant tumors.

METHODS

The prospective study included 25 parotid tumors in 21 patients. Neck computed tomography (CT) was performed using a multislice CT unit. A full-neck CT examination was done at 30 seconds after completion of contrast injection, and then tumor-level images were obtained at 90 seconds and at 5 and 25 minutes. Computed tomography number (lesion density in Hounsfield units) was determined at each phase, and differences within and among tumor groups were statistically analyzed. Diagnoses were confirmed by histopathology.

RESULTS

There were 11 Warthin tumors, 8 pleomorphic adenomas, 5 malignant tumors, and 1 basal cell adenoma. Ten Warthin tumors showed rapid contrast enhancement at 30 seconds and rapid reduction of enhancement from the first to the fourth phase. The basal cell adenoma showed also a peak enhancement at 30 seconds. Seven pleomorphic adenomas showed increased enhancement through the first 3 phases. Four malignant tumors showed peak enhancement at 90 seconds. Statistically significant differences within and among tumor groups were determined.

CONCLUSIONS

The data suggest that peak tumor enhancement at 30 and 90 seconds, respectively, might identify Warthin and malignant tumors. Increased enhancement through all phases might be an indicator for diagnosing pleomorphic adenomas.

Neither MRI, CT nor US is superior to diagnose tumors in the salivary glands--an extended case study

OBJECTIVES

Ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) are the most common radiological procedures for the diagnosis of tumor-like lesions of the salivary glands. The aim of the present study was to determine whether MRI or CT provide additional information besides that delivered by US.

STUDY DESIGN/METHODS

109 patients with a tumor-like lesion of the salivary glands underwent surgery. MRI and CT were arranged in 73 and in 40 patients respectively, whereas all 109 patients were prospectively diagnosed by US. The results of CT, MRI and US were compared with the histological outcome. Furthermore, the recent rise in the number of CT and MRI studies was investigated.

RESULTS

On CT and MRI, there was no rise in the percentage of malignant tumors or advanced surgical procedures. In respect of the radiological assessment of the lesion (benign/malignant) and the correct diagnosis, CT, MRI and US were comparable in terms of sensitivity, specificity and accuracy. No significant difference was found in the Chi-square test (p > 0.05).

CONCLUSION

The evaluation of the preoperative results of CT, MRI and US revealed no advantage for CT or MRI; these procedures are only required in specific cases. An update or revision of the current preoperative diagnostic management is deemed necessary.