The differential diagnosis of lymphoepithelial lesion of the salivary gland.

The differential diagnosis of salivary gland lesions with epithelial components and lymphoid stroma is often challenging. Salivary gland carcinoma with tumor-associated lymphoid proliferation, tumors composed of both epithelial and lymphoid components, lymphoid neoplasms in the salivary gland, and inflammatory lesions are all included in this category. It encompasses inflammatory lesions and neoplastic lesions. With the exception of Warthin tumors, these lesions are rare, making them more difficult to diagnose. Carcinoma showing thymus-like elements has recently been reported in the salivary gland. Similar to thymic carcinoma, tumor cells are positive for CD5 and are accompanied by T lymphocytes.

Growth rates over time of unoperated parotid benign tumors.

INTRODUCTION: The treatment of parotid benign tumor is in principle surgery, but observation may be necessary in some cases. The purpose of this study was to investigate the growth rates over time of unoperated parotid benign tumors. METHODS: We retrospectively reviewed the medical records of 63 patients with unoperated parotid benign tumors diagnosed at our institution between January 2010 and December 2022. RESULTS: Forty-nine of the 63 patients had a Warthin tumor and 13 patients had a pleomorphic adenoma. On average, the unoperated parotid benign tumors grew 0.02 cm in length and 0.4 cm3 in volume per year. Compared to pleomorphic adenomas, Warthin tumors were more predominant in male patients and in those with a smoking history and a longer duration of smoking history; patients with Warthin tumors were also followed up longer (p < 0.05). However, the length and volume growth rates of unoperated Warthin tumors and pleomorphic adenomas did not significantly differ. CONCLUSION: Surgery is the standard treatment for parotid benign tumors. However, small benign parotid tumors identified during preoperative examination can be observed through close follow-up, taking into account the patient's medical and general condition.

Ultrasonography characteristics of cystic components in primary salivary gland tumors.

OBJECTIVES: The present study aimed to characterize the ultrasonography (US) features of cystic components in salivary gland tumors (SGTs). MATERIALS AND METHODS: A total of 207 patients (218 lesions) with pathologically confirmed primary SGTs were analyzed. Preoperative US revealed the presence of cystic components in lesions. Lesion size, shape, margin, and US findings of the cystic components, including number, distribution, margin, occupying rate, and internal characteristics, were evaluated. RESULTS: Similarities were observed between the US performance of benign SGTs (B-SGTs) and malignant SGTs (M-SGTs) with cystic components. Differences in sex and age of patients, number, distribution, and internal characteristics of cystic components were statistically significant. For SGTs with cystic components, the proportions of M-SGTs to ill-defined margins (P = 0.002), eccentric distribution (P = 0.019), and none of the internal characteristics (P = 0.019) were significantly higher than those of B-SGTs. Younger age (P = 0.001), eccentric distribution (P = 0.034) and ill-defined margin (P < 0.001) were risk factors for diagnosing M-SGTs. Cystic component features needed to be combined with lesion indicators (border and shape) to improve diagnostic sensitivity. CONCLUSIONS: US features of the B-SGTs and M-SGTs were significantly different. Cystic component is of interest in the US-related differential diagnosis of B-SGT and M-SGT. CLINICAL RELEVANCE: Cystic components are potentially valuable in the differential diagnosis of B-SGTs and M-SGTs on US.

Exudative glomerulonephritis associated with acute leptospirosis in dogs.

In the past 20 years in Switzerland, dogs with suspect acute leptospirosis frequently showed severe glomerular changes that had not been previously reported. These features were characterized by abundant extravasated erythrocytes and fewer neutrophils accompanied by marked fibrin exudation into the urinary space that was interpreted as an exudative glomerulonephritis (GN). This retrospective study describes this significant glomerular pathological change and investigates the association with leptospirosis. Tissues from 50 dogs with exudative GN, retrieved from 2 pathology archives in Switzerland were reviewed using hematoxylin and eosin, periodic acid-Schiff, phosphotungstic acid-hematoxylin, and Warthin and Starry stains. Clinical and postmortem data were collected for each case. Immunohistochemistry (IHC) and/or polymerase chain reactions were used as confirmatory tests for leptospirosis. While all 50 cases had clinical and pathological features supporting a diagnosis of leptospirosis, 37 cases were confirmed for the disease. Using a LipL32 antibody in addition to the OMV2177 antibody raised against the lipopolysaccharide of Leptospira interrogans serovar Copenhageni increased the detection rate of Leptospira by IHC in exudative GN from 24% to 62%. Signalment, seasonality, clinical signs, blood results, and pathological changes in dogs with exudative GN were similar to those reported for dogs without GN and confirmed infection by Leptospira spp.. Exudative GN was common among Swiss dogs with leptospirosis where it caused acute severe disease. Leptospirosis should be considered as a cause of this new pathologic feature by the pathologist. The pathogenesis remains unclear, but involvement of a geographic-specific serovar with unique virulence factors is suspected and warrants further investigation.

Trend changes in the incidence of benign parotid tumours in the last 30 years in a Spanish population.

PURPOSE: To study the demographics and clinical characteristics of benign parotid tumours, focusing on the evolution of the incidence of Warthin tumour (WT) in recent years. METHODS: A retrospective observational study is designed of patients diagnosed with a benign parotid tumour in a single tertiary hospital centre, from 1994 to 2021. The evaluation of the relationship between the different variables, and the changes in tumour incidence, is carried out using an analysis of standardized residuals. RESULTS: The study evaluated 279 patients, and the total of benign parotid tumours was 291. The most frequent type of tumour was pleomorphic adenoma (PA) (52.7%), followed by WT (37.6%). WT was more frequent in men (79%), and PA in women (55.8%). Smoking history is significantly high in patients with WT (83%), as well as mid-age, compared to PA. CONCLUSIONS: It seems to be an increase in the proportion of WT compared to PA in recent years. These changes can be concerning tobacco use and older patients at diagnosis in our series.

Warthin-like papillary carcinoma: Case report.

Warthin-like papillary thyroid carcinoma is a rare variant of papillary carcinoma with a very good prognosis. It is often associated with lymphocytic thyroiditis. Due to its typical histological picture resembling Warthin's salivary gland tumor, the histological diagnosis is not difficult, usually does not require an accompanying immunohistochemical examination and is based on the presence of nuclear features typical of papillary carcinoma and the presence of oncocytes in a background of rich lymphocyte infiltrate. The preoperative cytologic examination is challenging, as many other lesions may have a similar picture. Women are more likely to get affected. It appears a decade earlier than the classic variant. Clinically, it presents similarly to a conventional papillary carcinoma. In our case report, we would like to present the case of a 56-year-old woman with non-toxic multinodular goiter, in whom the presence of this rare variant of papillary carcinoma was revealed by histological examination.

An unexpected case of Borrelia garinii liver infection.

BACKGROUND: Lyme borreliosis is the most prevalent arthropod-borne infection in the Northern Hemisphere. In Europe, Borrelia afzelii is predominantly involved in cutaneous manifestations, Borrelia garinii and Borrelia bavariensis in neurological manifestations, and Borrelia burgdorferi sensu stricto in articular ones. Liver impairement is not classical in Lyme borreliosis. Diagnosis is currently mainly based on serological testing, and is challenging in immunocompromised patients. CASE PRESENTATION: We report the first case of B. garinii infection revealed by liver involvement in an immunocompromised man. A 73-year-old man with marginal zone lymphoma, treated with bendamustine and rituximab, developed intermittent fever and inflammatory syndrome. Microbial investigations were all negative and FDG-PET showed complete remission of the lymphoma. Three months later, liver biopsy was performed and histology revealed spirochetes-like bacteria. Microbial diagnosis was performed by 16S rDNA sequencing, flagellin (flaB) gene sequencing and multi-locus sequence typing and identified B. garinii. The patient recovered successfully after a three weeks course of antibiotics. Diagnosis was challenging because Borrelia hepatic involvement is unusual and no erythema migrans nor tick bite were notified. CONCLUSION: This case highlights that unexplained fever and inflammatory syndrome in immunocompromised patients warrants specific investigations to identify bacteria such as spirochetes.

Experience with follow-up strategy in selected patients with Warthin tumour diagnosed by ultrasound-guided fine-needle aspiration biopsy (FNAB).

PURPOSE: Warthin tumour (WT) management options comprise surgery or follow-up. The purpose of this study was to asses our experience with the follow-up strategy in selected patients with an ultrasound-guided fine-needle aspiration biopsy (FNAB) showing WT. METHODS: We performed a retrospective analysis of patients diagnosed with WT using FNAB between 1.1.2006 and 31.12.2019. Patients were divided into three groups according to the therapeutic approach-immediate surgery, follow-up or surgery and follow-up. RESULTS: 323 patients were diagnosed with WT and met the study's inclusion criteria (154 women, 47.7% and 169 men, 52.3%). 192 patients were operated right after the diagnosis, 109 patients were observed with their first detected tumour and 22 patients had parotid WT surgery and were in the wait-and-scan protocol with a contralateral tumour, recurrence or both. The growth rate (GR) of observed WT was highly variable (mean GR 1.0 mm/year (5%), median GR 0.8 mm (9%), range - 19.7 to +20.0 mm/year). From 131 patients in the follow-up group, 19 patients underwent surgery and definitive histology revealed 17 WTs and 2 adenocarcinomas. However, these 2 patients had changes in sonographic findings at their next control. The mean observation time was 44.7 months (range 12-138 months) in patients followed exclusively at our institution and 50.9 months (range 12-110 months) in patients observed in cooperation with an otorhinolaryngologist at the patients' place of residence. CONCLUSION: Ultrasound-guided FNAB is an accurate and simple method in WT diagnosis and based on its result a follow-up strategy can be chosen for selected patients with WT.

Detection of melanin in the rat skin.

Melanogenesis disorder is called dyschromia, is involved in various conditions including vitiligo, solar lentigo, and melanoma, the last of which is the most malignant type of skin cancer. AIM: The aim of study was focused on histological visualization of melanogenic system. MATERIALS AND METHODS: To investigate the roles of melanocytes and melanin, we used a rat skin as an experimental animal. Samples were stained using hematoxylin-eosin, the Schmorl's technique, the Fontana-Masson technique, the Warthin-Starry technique, and the S100 immunohistochemistry marker technique. Microscopy images were analyzed using the ImageJ free software protocol. RESULTS: We found Fontana-Masson staining to be the most suitable for obtaining reliable results compared with the other methods, which had more disadvantages. We also found the S100 marker staining to be an effective tool for measuring the melanocyte count. CONCLUSIONS: We consider the ImageJ processing protocol and staining procedures to be useful tools to estimate melanin and melanocyte pathology.

Ultrasound-guided ethanol sclerotherapy for non-surgical treatment of Warthin's tumor.

BACKGROUND: Currently, the first line treatment for Warthin's tumor (WT) is parotidectomy. There is a paucity of data evaluating the safety and efficacy of non-surgical treatments for patients not amenable to surgery. Ultrasound guided ethanol sclerotherapy (UGES) has been successfully used for the management of lymphangiomans of the head and neck, thyroid nodules, and thyroid cysts. This is the first study to implement and assess the success of UGES for management of WT. METHODS: We report two patients with WT, with a total of 3 masses, who underwent UGES. All procedures were performed in the clinic. The primary outcome measured was the tumor volume reduction rate (VRR), patient satisfaction, and complications observed at follow-up. RESULTS: Both patients experienced a significant reduction in tumor size upon follow up. VRR for the three treated tumors were 67.30%, 98.32%, and 55.73%. Patient were very satisfied with the results and noted significant cosmetic improvement. No complications were observed at follow-up. CONCLUSIONS: Ultrasound guided ethanol sclerotherapy may be a viable option for conservative treatment of Warthin's tumor in patients unsuitable or unwilling to undergo surgical resection.

Imaging quality of PROPELLER diffusion-weighted MR imaging and its diagnostic performance in distinguishing pleomorphic adenomas from Warthin tumors of the parotid gland.

The aim of this study was to evaluate the imaging quality and diagnostic performance of fast spin echo diffusion-weighted imaging with periodically rotated overlapping parallel lines with enhanced reconstruction (FSE-PROP-DWI) in distinguishing parotid pleomorphic adenoma (PMA) from Warthin tumor (WT). This retrospective study enrolled 44 parotid gland tumors from 34 patients, including 15 PMAs and 29 WTs with waived written informed consent. All participants underwent 1.5 T diffusion-weighted imaging including FSE-PROP-DWI and single-shot echo-planar diffusion-weighted imaging (SS-EP-DWI). After imaging resizing and registration among T2WI, FSE-PROP-DWI and SS-EP-DWI, imaging distortion was quantitatively analyzed by using the Dice coefficient. Signal-to-noise ratio and contrast-to-noise ratio were qualitatively evaluated. The mean apparent diffusion coefficient (ADC) of parotid gland tumors was calculated. Wilcoxon signed-rank test was used for paired comparison between FSE-PROP-DWI versus SS-EP-DWI. Mann-Whitney U test was used for independent group comparison between PMAs versus WTs. Diagnostic performance was evaluated by receiver operating characteristics curve analysis. P < 0.05 was considered statistically significant. The Dice coefficient was statistically significantly higher on FSE-PROP-DWI than SS-EP-DWI for both tumors (P < 0.005). Mean ADC was statistically significantly higher in PMAs than WTs on both FSE-PROP-DWI and SS-EP-DWI (P < 0.005). FSE-PROP-DWI and SS-EP-DWI successfully distinguished PMAs from WTs with an AUC of 0.880 and 0.945, respectively (P < 0.05). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy in diagnosing PMAs were 100%, 69.0%, 62.5%, 100% and 79.5% for FSE-PROP-DWI, and 100%, 82.8%, 75%, 100% and 88.6% for SS-EP-DWI, respectively. FSE-PROP-DWI is useful to distinguish parotid PMAs from WTs with less distortion of tumors but lower AUC than SS-EP-DWI.

Quantification of heterogeneity to classify benign parotid tumors: a feasibility study on most frequent histotypes.

Aim: To differentiate Warthin tumors (WTs) and pleomorphic adenomas (PAs) measuring heterogeneity of intravoxel incoherent motion (IVIM) and dynamic-contrast enhanced-magnetic resonance imaging biomarkers. Methods: Volumes of interest were traced on 18 WT and 18 PA in 25 patients. For each IVIM and dynamic-contrast enhanced biomarker, histogram parameters were calculated and then compared using the Wilcoxon-signed-rank test. Receiver operating characteristic curves and multivariate analysis were employed to identify the parameters and their pairs with the best accuracy. Results: Most of the biomarkers exhibited significant difference (p < 0.05) between PA and WT for histogram parameters. Time to peak median and skewness, and D* median and entropy showed the highest area under the curve. No meaningful improvement of accuracy was obtained using two features. Conclusion: IVIM and dynamic-contrast enhanced histogram descriptors may help in the classification of WT and PA.

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.

The diagnostic value of Superb Microvascular Imaging in identifying benign tumors of parotid gland.

BACKGROUND: We compared the ultrasound features, superb microvascular imaging (SMI) and micro vessel density (MVD) of pleomorphic adenoma (PA), Warthin's tumor (WT) and basal cell adenoma (BCA) to explore the clinic value of SMI in differential diagnosis of benign tumors of parotid gland. METHODS: The vascular distributions and grade by color doppler flow imaging (CDFI) and SMI, as well as vascular index (VI) of 249 parotid gland masses from 217 patients were analyzed. RESULTS: The internal echogenicity of BCA are more homogeneous in comparing with WT and PA(P < 0.05). By SMI, the vascular distribution and vascular grade in PA were mainly peripheral (33.1%) and avascular (25.7%), Grade 1 (27.8%) and Grade 0 (25.7%). WT were mainly central (31.3%) and mixed distribution (34.9%), in Grade 3 (37.3%) and Grade 2 (36.2%). BCA was mainly peripheral (33.3%) and mixed distribution (33.3%), in Grade 2 (33.3%) and Grade 3 (33.3%). The overall detection rate of SMI for vascular Grade 2 and 3 was significantly higher than that of CDFI (P < 0.05). Both VI and MVD were lowest in PA, highest in WT (P < 0.001). The VI by SMI was correlated with MVD (P < 0.001). The correlation index between vascular distribution and grade by SMI and MVD were significantly higher than CDFI. CONCLUSION: SMI can provide low-velocity blood flow information, which is helpful for the differential diagnosis of common benign tumors of parotid gland, and is expected to be more widely used.

Cytopathology and diagnostics of Warthin's tumour.

Warthin's tumour (WT) is a benign epithelial salivary tumour, one type of salivary adenoma. Histologically, WT is structured of two components, epithelial tissue that often lines cystic formations and lymphoid tissue in the tumour stroma. FNA is a reliable diagnostic approach in the diagnosis of salivary gland lesions allowing a highly accurate categorization of benign tumour-like lesions, benign tumours and malignant tumours. In the proposed Milan reporting system of salivary gland lesions, WT is categorized in the IVA group of benign neoplasms. Accurate cytological diagnosis is straightforward when three characteristic components are present: oncocytes, either isolated or associated in clusters, lymphocytes and lymphoid cells and often an inflammatory/necrotic-like substance. Also, specific features of scintigraphy and radiological imaging contribute to the diagnosis of WT. WT is categorized according to Seifert G. et al in 4 types, depending on the proportions of the epithelial component and lymphoid stroma. Differential cytopathological and pathohistological diagnosis include other salivary gland lesions with lymphoid, oncocytic epithelial and cystic components. In some cases, such as the metaplastic WT variant, there are additional cytopathological and histological diagnostic difficulties. Moreover, bilateral, multicentric or multiple and infrequently seen extra-salivary localizations of WT are associated with further cytopathological diagnostic difficulties. Also, a rare possibility of malignant transformation of the epithelial or lymphoid component of WT as well as possible association with other primary tumours remains a challenge in accurate cytopathological and histological diagnosis of WT.

Warthin's tumour seems to be the most common benign neoplasm of the parotid gland in Germany.

PURPOSE: Recent reports indicate an increase in the prevalence of Warthin's tumours (adenolymphoma) with percentages which exceed that of pleomorphic adenomas (PA) in the same registries. The purpose of this study is to analyse a large cohort of benign parotid tumours in relation to various demographic and other patients' characteristics that might affect their incidence. METHODS: A retrospective review of prospective collected data was performed on all patients who have been operated for a parotid mass in the last 5 years. A total of 474 patients with benign lesion were included in the study. Age, gender, smoking status, histological diagnosis, site of lesion, and size of tumour were recorded. RESULTS: Warthin's tumours were the most common benign lesions, found in 201 (42.4%) parotic glands followed by pleomorphic adenomas found in 138 (29.1%) of these surgical cases. Patients with WT had a mean age of 61.6 years instead of 52 years for PA patients (t = 6.589, p < 0.001). The vast majority (93%) of patients with WT had a current or previous history of smoking compared with 47% of PA patients (p = 0.001). There was a male predominance regarding WT with a male:female (M:F) ratio of 2.3:1, whereas the corresponding ratio of PA was 1:1.4. CONCLUSIONS: This study confirms the increased regional prevalence of WT reported in studies mainly carried out in central Europe. This could affect future management of WT, which remains largely controversial due to the extremely low malignant potential reported, concurrently with its higher rates of multiplicity and recurrence, as well as the moderately accurate results of FNA biopsies.

Change in Warthin's tumor incidence: a 20-year joinpoint trend analysis.

PURPOSE: The incidence of Warthin's tumor (WT) has increased worldwide. In this study, we aimed to evaluate the incidence of WT in our hospital, which provides health care for an extremely large population. METHODS: We retrospectively evaluated 573 patients, comprising 345 males and 228 females, who all experienced parotid tumor for the past 20 years. Patients with WT that were operated in the last 20 years were evaluated according to the number of patients per year to determine the annual WT increase trend. RESULTS: In the distribution of WT over the years of surgery, the ratio of WT to all tumors irregularly changed. Furthermore, the total number of parotidectomies per year increased in time. We investigated whether WT had any increasing trend over the years. The annual percentage change (APC) of WT was calculated, and according to the segmented regression analysis, the APC was insignificant (APC = 4.3, 95% CI = - 3.6-12.9, P = 0.300). CONCLUSION: The incidence of WT has increased across the world. However, in our study, no significant APC was observed according to the segmented regression analysis.

Cytomorphological findings in diagnosis of Warthin tumor

Background/aim: To define the cytomorphologic findings leading to difficulties in diagnosis of Warthin tumors (WTs). Materials and methods: Forty-eight histopathologically diagnosed WT patients who had fine needle aspiration cytology preoperatively were reevaluated for defining the presence or absence of lymphocytes, oncocytic cell layer, oncocytic cell papillae, granular debris background, mucoid background, macrophages, polymorphonuclear cells, mast cells, squamous-like cells, atypical vacuolated cytoplasmic cells, and giant cells. Results: Forty-seven tumors were in the parotid gland and one in the submandibular gland. There were 37 (77%) male and 11 (23%) female patients. Cytopathologically in 36 patients the diagnosis was benign neoplasm (WT); in 6, other benign entities; and in 6, suspicious for malignancy. The main characteristic cytomorphologic features of WTs were as follows: 92% lymphoid cells, 83% oncocytic cell layers, and 67% granular debris background. These percentages were 67%, 17%, and 17% in the benign cytology group and 67%, 50%, and 17% in the suspicious for malignancy group, respectively. Conclusion: Absence or lack of main features of WTs with or without presence of squamous-like cells, vacuolated cytoplasmic cells, and inflammatory reaction may cause diagnostic dilemma. The presence of the mast cells accompanied by epithelial tissue was striking for WT diagnosis.

Histochemical and immunohistochemical detection of pathogenic leptospires serovars in tissues of some captive wildlife from a University zoo in Nigeria.

The detection and documentation of pathogenic Leptospira serovars in wild captive and zoological garden animals are scarce in literature from Nigeria. The knowledge of the prevalence of prevalence of pathogenic Leptospira serovars in these animals as a zoonotic risk to workers, zoo visitors and the general public is essential. This investigation was carried out on archival kidney and liver samples of captive and Zoological Garden animals (66) of an institutional facility, submitted for necropsy to the Department of Veterinary Pathology between the periods of 2010-2015. The gross diagnosis reports were obtained from the necropsy records, detection of pathogenic Leptospira serovars was by Warthin Starry silver staining and immunohistochemistry techniques using standard methods. Six samples out of the sixty-six samples were positive for leptospira four samples were positive by silver stain method, while two samples were positive by immunohistochemistry. In this study, serovar Pomona and grippotyphosa were detected in the foxes while serovar Pomona was detected in the horse. This study has revealed the presence of pathogenic leptospires in some captive wild and zoological garden animals.

Rising incidences of Warthin's tumors may be linked to obesity: a single-institutional experience.

PURPOSE: Recently, there has been an increase in the number of reported Warthin's tumors, but few risk factors have been described for this benign tumor. Yet, smoking is the only evidently identified risk factor. Obesity and the metabolic syndrome are causally linked to or a risk factor for a variety of diseases. Therefore, we analyzed whether metabolic syndrome, including obesity, might influence the incidence of Warthin's tumors. METHODS: In this retrospective study, we evaluated 197 patients with Warthin's tumor. We assessed the tumor size, the body mass index (BMI), comorbidities related to the metabolic syndrome, and cigarette and alcohol consumption. Additionally, we evaluated several blood parameters and their influence. RESULTS: Warthin's tumor patients had a significantly higher BMI in comparison to patients with other benign parotid gland tumors (29.1 versus 26.2, p < 0.0001). The rate of metabolic syndrome-associated comorbidities was higher in Warthin's tumor patients (62.4% versus 35.2%, p < 0.0001). CONCLUSION: Our results might be the first step to recognize obesity and its consequences as a co-driver in the formation of Warthin's tumors. Nevertheless, further studies are requested to validate our results and to answer the question whether obesity or the metabolic syndrome are integrally linked to Warthin's tumors.