Smoking and the development of Warthin's tumour of the parotid gland

Different MRI-based radiomics models for differentiating misdiagnosed or ambiguous pleomorphic adenoma and Warthin tumor of the parotid gland: a multicenter study

Purpose

To evaluate the effectiveness of MRI-based radiomics models in distinguishing between Warthin tumors (WT) and misdiagnosed or ambiguous pleomorphic adenoma (PA).

Methods

Data of patients with PA and WT from two centers were collected. MR images were used to extract radiomic features. The optimal radiomics model was found by running nine machine learning algorithms after feature reduction and selection. To create a clinical model, univariate logistic regression (LR) analysis and multivariate LR were used. The independent clinical predictors and radiomics were combined to create a nomogram. Two integrated models were constructed by the ensemble and stacking algorithms respectively based on the clinical model and the optimal radiomics model. The models' performance was evaluated using the area under the curve (AUC).

Results

There were 149 patients included in all. Gender, age, and smoking of patients were independent clinical predictors. With the greatest average AUC (0.896) and accuracy (0.839) in validation groups, the LR model was the optimal radiomics model. In the average validation group, the radiomics model based on LR did not have a higher AUC (0.795) than the clinical model (AUC = 0.909). The nomogram (AUC = 0.953) outperformed the radiomics model in terms of discrimination performance. The nomogram in the average validation group had a highest AUC than the stacking model (0.914) or ensemble model (0.798).

Conclusion

Misdiagnosed or ambiguous PA and WT can be non-invasively distinguished using MRI-based radiomics models. The nomogram exhibited excellent and stable diagnostic performance. In daily work, it is necessary to combine with clinical parameters for distinguishing between PA and WT.

A retrospective study of parotid gland tumors at a single institution

The aim of the present study was to analyze the clinical characteristics, surgical treatments and clinical outcome of patients with parotid gland tumors and to compare the results with those cited in the literature. A retrospective study was conducted in 140 patients (male, n=77; female, n=63) with parotid gland tumors who underwent parotidectomy at Hokuto Hospital Department of Otolaryngology-Head and Neck Surgery (Obihiro, Japan) between April 2007 and December 2021. Of the 140 patients enrolled, 118 (84.3%) patients had benign tumors, including 63 (45%) patients with pleomorphic adenomas and 43 (30.7%) patients with Warthin tumors, and 22 patients (15.7%) had parotid carcinoma. Comparison of the three groups of patients with parotid gland tumors indicated that pack years as an indicator of smoking status were significantly higher in patients with Warthin tumors than in those with parotid carcinomas (P=0.011) or pleomorphic adenoma (P<0.001). Fine-needle aspiration cytology (FNAC) was non-diagnostic for only 6 (4.3%) of 140 patients. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of FNAC by both conventional smear and liquid-based cytology (LBC) for parotid carcinomas were 70, 99, 93.3, 94.4 and 82.9%, respectively. Among the 22 patients with parotid carcinoma, extended total/total and superficial parotidectomy were performed in 10 (45%) and 11 (50%) cases, respectively. Total and selective neck dissection of the area from level II to I, II and III were performed in 6 (24%) and 7 (32%) patients, respectively. Postoperative radiotherapy (50 Gy) was performed in 15 (68%) patients. The overall survival (OS) and disease-free survival (DFS) rates at 5 years were 51.5 and 76.4%, respectively. Univariate analysis revealed that age >65 years was significantly associated with poorer 5-year OS (P<0.001) and DFS (P<0.001). Multivariate analysis revealed that an age of more than 65 years combined with high-grade histologic malignancy was associated with worse DFS (P=0.02; hazard ratio, 3.628; 95% confidence interval, 1.283-9.514). In conclusion, the clinical characteristics and treatment outcomes of parotid gland tumors were consistent with the results of previous reports. Smoking may be closely related to the pathogenesis of Warthin tumors. LBC potentially provides improved accuracy in FNAC.

Tobacco Smoking and Alcohol Consumption Are Related to Benign Parotid Tumor: A Nested Case-Control Study Using a National Health Screening Cohort

OBJECTIVES

To evaluate the relationship among smoking, alcohol consumption, and obesity and benign or malignant parotid tumors in a Korean population.

METHODS

The Korean National Health Insurance Service-Health Screening Cohort (for ≥40-year-olds) was assessed from 2002 to 2013. In total, 336 benign parotid tumors and 46 malignant parotid tumors were matched with controls at a ratio of 1 to 4 with respect to age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia. We analyzed previous histories of smoking, alcohol consumption, and obesity. By unconditional logistic regression analyses, the crude and adjusted odds ratios (ORs) were investigated and the 95% confidence intervals (CIs) were counted.

RESULTS

The estimated annual incidence of the benign parotid tumors was 5.66 per 100,000, and that of the malignant parotid tumor was 0.81 per 100,000. The adjusted ORs of smoking for the benign parotid tumors was 2.52 (95% CI, 1.84 to 3.46). This finding was consistent in the subgroups of <60 years old, ≥60 years old, and men. The adjusted ORs of alcohol consumption for the benign parotid tumors showed the statistical significance only in women (adjusted OR, 2.35; 95% CI, 1.10 to 5.00). Obesity did not reach a statistical significance in any analysis.

CONCLUSION

Benign parotid tumor was related with smoking, and it was linked with alcohol consumption in women only.

A Case-Control Study of Risk Factors for Salivary Gland Cancer in Canada

Aim. To assess the effect of various lifestyle risk factors on the risk of salivary gland cancer in Canada using data from a population-based case-control study. Methods. Data from a population-based case-control study of 132 incident cases of salivary gland cancer and 3076 population controls were collected through self-administered questionnaire and analysed using unconditional logistic regression. Results. Four or more servings/week of processed meat product was associated with an adjusted odds ratio (OR) and corresponding 95% confidence interval (CI) of 1.62 (1.02-2.58). Nonsignificantly increased ORs were also related to obesity, >7 drinks/week of alcohol consumption, and occupational exposure to radiation. Furthermore, nonsignificantly decreased ORs were found to be associated with high education level (>12 years) (OR = 0.65), high consumption of spinach/squash (OR = 0.62) and all vegetables/vegetable juices (OR = 0.75), and >30 sessions/month of recreational physical activity (OR = 0.78). Conclusions. This study suggests positive associations with consumption of processed meat, smoking, obesity, alcohol drinking, and occupational exposure to radiation as well as negative associations with higher education, consumption of spinach/squash, and physical activity, which suggest a role of lifestyle factors in the etiology of salivary gland cancer. However, these findings were based on small number of cases and were nonsignificant. Further larger studies are warranted to confirm our findings.

Warthin's Tumour: A Case Report and Review on Pathogenesis and its Histological Subtypes

Warthin's tumour/ Papillary cystadenoma lymphomatosum (PCL) constitutes a minority of salivary gland neoplasms and it is a monomorphic adenoma which primarily involves the parotid gland. Warthin's tumour shows multiple cysts that have numerous papillations covered by bilayered columnar and basaloid oncocytic epithelium. The connective tissue portion shows proliferation of follicle- containing lymphoid tissue which necessitates careful distinction for diagnosis. Although, Warthin's tumour presents as a clinically benign, slow-growing, usually asymptomatic lesion with low rates of recurrences and malignant transformation, but still this tumour is considered unique because of its histological appearance and unknown origin and pathogenesis. Here, we report a case of Warthin's tumour of five years duration in a 50-year-old male patient in the right parotid gland and also review and discuss various concepts concerning the development of this tumour along with a comprehensive literature on its clinic-pathologic features.

Tumor de Warthin da glândula parótida: estudo de 70 casos

OBJETIVO: Relatar as características clínicas, tratamento e complicações.dos tumores de Warthin. MÉTODOS: Estudo retrospectivo com 70 pacientes submetidos à ressecção de cistoadenoma papilífero linfomatoso,. Variáveis analisadas: idade, sexo, etnia, presença ou não de tabagismo, sítio primário do tumor, tamanho do tumor em centímetros, presença de bilateralidade, tipo de operação, multicentricidade, complicações do tratamento, presença de recidiva no seguimento e tempo de seguimento.. RESULTADOS: Quarenta e quatro pacientes (62,8%) eram do sexo masculino e 26 (37,2%), do sexo feminino, com média etária de 56,7 anos, O tabagismo estava presente em 55 (78,6%) pacientes, (94,3%) dos tumores eram unilaterais e quatro (5,7%) bilaterais, com tamanho médio de 4,1cm ao exame físico. As complicações foram 14 (19%) casos de paresia e/ou paralisia facial, seroma em 10 (13,8%), síndrome de Frey em três (4%), hematoma em dois (2,7%) e infecção de ferida operatória em um (1,5%) caso. CONCLUSÃO: O tumor de Warthin tem maior incidência no sexo masculino, em tabagistas e localização unilateral predominante na glândula parótida. A parotidectomia superficial com preservação do nervo facial mostrou-se eficaz em 100% casos. As complicações encontradas foram paresias ou paralisias transitórias, seroma, síndrome de Frey, hematoma e infecção de ferida operatória.

Smoking and risk of parotid gland tumors: a nationwide case-control study

BACKGROUND

Because existing data regarding the relation between smoking and salivary gland tumors are sparse, tobacco is currently not classified as a salivary gland carcinogen. The objective of the current study was to assess the association between smoking and benign and malignant parotid gland tumors (PGTs) in a nationwide study.

METHODS

The sample included 459 patients with incident PGT, aged > or =18 years, who were diagnosed between 2001 and 2003 and a group of 1265 individually matched, population-based controls. Analyses of the risk of PGT associated with various smoking variables were performed by using conditional logistic regression. Data also were stratified by histologic type; statistical significance tests were 2-sided.

RESULTS

Ever smoking cigarettes was associated with an odds ratio (OR) of 1.66 (95% confidence interval [95% CI], 1.31-2.11) for developing a PGT. The risk was strongest for early ages at smoking initiation, and trends of increasing risk were observed with increasing smoking intensity, pack-years, latent period, and smoking duration (P for trend <.001 for each). Analysis by histologic type indicated remarkably high risks for Warthin tumor (OR for ever cigarette smokers: 15.3; 95% CI, 6.1-38.5). For pleomorphic adenomas and malignant tumors, the risks associated with ever smoking were 1.01 (95% CI, 0.75-1.37) and 1.69 (95% CI, 0.81-3.51), respectively.

CONCLUSIONS

Smoking plays an important role in the development of Warthin tumor. Although no association was observed for pleomorphic adenoma, the possible indication of increased risk of malignant tumors requires further investigation in larger studies.

Evidence of lymphangiogenesis in Warthin's tumor of the parotid gland

The details of the pathogenesis of cystadenolymphoma (Warthin's tumor) of the parotid gland are still unclear. Neovascularization is considered to be a pivotal factor for solid tumor progression and biological behavior of the tumor. Using double-labeling immunohistochemistry for LYVE-1 and CD34 (specific markers for lymphatic and vascular endothelial cells, respectively) this study analyzes lymphatic vessel density (LVD) and blood vessel density (BVD) in 10 Warthin's tumors and 10 pleomorphic adenomas of the parotid gland as well as in 5 normal parotid glands and 5 normal parotid lymph nodes. There was no significant difference in the intratumoral LVD and BVD among pleomorphic adenoma and normal parotid gland tissue. In contrast, the intratumoral LVD and BVD were significantly higher in Warthin's tumor than pleomorphic adenoma, normal parotid gland and parotid lymph node (P<0.0001 versus P<0.004). The increase in lymphatic vessels in Warthin's tumor suggests that epithelial tumor cells might promote lymphangiogenesis in this kind of lesions.

Clinical features of cystadenolymphoma (Warthin’s tumor) of the parotid gland: A retrospective comparative study of 96 cases

The details of the etiopathogenesis of cystadenolymphoma (Warthin's tumor) are still unclear. To explore the possible risk factors for the development of this tumor, medical records of 81 patients with 96 Warthin's tumors of the parotid glands were compared retrospectively with those of 91 patients with pleomorphic adenoma. The medical history and clinical tumor characteristics of all patients were similar. There were no significant differences between these two patient groups with respect to concomitant diseases, regular medications, and preoperative laboratory findings. However, a significant male predominance of patients with Warthin's tumor could be noted (P<0.05). The male to female ratio was 3.3:1 in patients with Warthin's tumor. Multifocal Warthin's tumor were detected in five cases (6.2%), and 10 patients (12.3%) had bilateral lesions. The odds ratio for the incidence of Warthin's tumor among current smokers compared with never smokers was 8.3 (P<0.0001). Compared with never smokers, clearly higher odds of Warthin's tumor was observed in heavy smokers (more than 30 pack-years) (odds ratio=24.1, P<0.0001) than patients who smoked less than 30 pack-years (odds ratio=4.9, P<0.0001).

Mitochondrial DNA mutations in oral squamous cell carcinoma

It has previously been demonstrated that mitochondrial DNA (mtDNA) mutations within the ND2 gene of histologically normal parotid salivary gland tissue of smokers may be molecular biomarkers for smoking-induced mtDNA damage. Oral squamous cell carcinoma (SCC) is strongly related to cigarette smoking; therefore, we used PCR and direct sequencing to establish whether mtDNA mutations were also present in oral SCC which could be used as additional biomarkers for smoking-associated DNA damage. In addition to searching for mutations in the ND2 gene, the mitochondrial D-Loop was also analysed. Three mutation hotspots were observed in the D-Loop at nt 146, 152 and 186, two of which (nt 146 and 152) have also been implicated in oesophageal SCC, another smoking-related cancer. The mutation hotspot observed at nt 186 has not previously been reported in other tumours. Furthermore, we show that the mutations previously reported within the ND2 gene in normal parotid tissue of smokers were not evident in these samples, but that a mutation hotspot occurs at nucleotide 4917 in oral SCC. We also show that D-Loop mutations occur predominantly in male smokers and female non-smokers and that this association with gender is statistically significant (P = 0.003). We conclude that the mtDNA mutation hotspots found in this study, in particular nt 186, are potential biomarkers for oral SCC. However, owing to gender-specific differences in occurrence in smokers and non-smokers, and a lack of environmental smoking history, in general, it is difficult to associate these mutations with mtDNA damage induced by smoking. If the mutations observed in the subset of male patients are smoking induced, given our previous findings, mutation hotspots in the ND2 gene may be tissue specific suggesting the causative mutagens for mtDNA damage within these tissues are likely to be different.

Increased risk of breast cancer development after diagnosis of salivary gland tumour

The aim of this study was to evaluate whether patients with salivary gland tumours are at increased risk of developing breast cancer. A retrospective cohort study was performed. Female patients (n = 439) with a salivary gland tumour (major and minor) were included. The diagnosis was confirmed histologically. The median follow-up was 5.4 years. Fifteen patients out of 439 with a salivary gland tumour subsequently developed breast cancer, with a mean time interval of 64 months. On the basis of incidence rates in the general population 5.93 breast cancers would be expected. The standardised incidence ratio (SIR) was 2.5 (95% confidence interval: 1.4-4.2; P = 0.003). Increased SIRs were also observed for other solid malignancies, but the numbers were small (n < 5). It is concluded that female patients with a salivary gland tumour have a 2.5 times increased risk of developing breast cancer. Breast screening of these patients is therefore recommended.

Tissue that has lost its track: Warthin's tumour

The origin of cystadenolymphoma (Warthin's tumour) of the parotid gland is unknown. According to the most favoured hypothesis, Warthin's tumour results from the proliferation of salivary gland ductal cells that were entrapped in parotid lymph nodes during embryonal life. If this is correct, and the almost total lack of recurrence and malignant transformation of this lesion lends credence to this view, Warthin's tumour is correctly classified in the group of tumour-like lesions and should not be considered to be a monomorphic adenoma.

Identification of differentially expressed genes in salivary gland tumors with cDNA microarray

OBJECTIVE

The final goal of this study is to develop a pre-operative fine needle aspiration biopsy (FNA) diagnostic system based on gene expression profiles. As the first step to that end, the present study was performed to determine whether the cDNA microarray system is applicable for histological evaluation of parotid gland tumors.

METHODS

We investigated molecular characteristics on the basis of gene expression patterns of the two most common types of salivary gland tumors (pleomorphic adenomas and Warthin tumors) and normal salivary gland tissues, using the cDNA microarray system.

RESULTS

Pleomorphic adenomas and Warthin tumors can be classified by cDNA microarray. In pleomorphic adenomas, 11 independent genes were found to be up-regulated and 2 genes were down-regulated. In Warthin tumors, five independent genes were found to be up-regulated, and six genes were down-regulated. In hierarchical clustering analysis, cases were further grouped into two clusters according to the histological type. Furthermore, cDNA microarray enabled pleomorphic adenomas to be subclassified into three clusters according to the histological subtypes.

CONCLUSIONS

This study suggested that cDNA microarray may be useful and applicable for the pre-operative diagnosis (such as FNA) of the salivary gland tumor.

False diagnosis caused by Warthin tumor of the parotid gland combined with actinomycosis

A case is reported in which a unilateral parotid gland cystadenolymphoma was combined with actinomycosis. A 48-year-old woman presented with a mass in the left parotid region and paresis of the lower left palpebra. The computed tomography, echography, and parotid radiographic findings did not exclude a neoplasm of the left parotid gland. The ramus of the mandible was involved in the process. Intraoperative freezing histology, total parotidectomy, and partial mandibulectomy were performed, with sacrifice of the facial nerve followed by nerve reconstruction. The final histological evaluation was Warthin tumor with actinomycosis. Four years after treatment, the patient is free of disease. No similar cases seem to have been reported thus far.

Role of Epstein-Barr virus and cytomegalovirus in the etiology of benign parotid tumors

BACKGROUND

Pleomorphic adenomas and Warthin's tumors are the two most common benign parotid tumors. Previous studies investigating the role of viruses in tumorigenesis of these neoplasms have been conflicting. The aim of this study was to determine whether Epstein-Barr virus (EBV) or cytomegalovirus (CMV) might play a role in the pathogenesis of pleomorphic adenomas and Warthin's tumors.

METHODS

Paraffin-embedded surgical specimens of 24 pleomorphic adenomas, 10 Warthin's tumors, and 13 normal parotid tissues were obtained from the University of California-San Francisco Pathology Department. Genomic DNA was extracted from the specimens, and primers for connexin 26, a gap junction protein, were used to confirm the integrity of this DNA. The presence or absence of EBV and CMV DNA within the samples was determined with PCR-based assays, in which radiolabeled primers were used for maximal sensitivity of detection.

RESULTS

PCR analysis of serially diluted control DNA revealed that using radiolabeled primers, five copies of viral DNA could be detected. By use of this method, we showed that none of the 24 pleomorphic adenomas, 10 Warthin's tumors, or 13 normal parotid samples contained EBV DNA or CMV DNA.

CONCLUSIONS

These results do not support CMV or EBV as etiologic factors in pleomorphic adenomas or Warthin's tumors. In addition, normal parotid seems not to harbor either of these viruses. Future studies with larger numbers of specimens are needed to confirm these findings.

Steroid hormone receptors in parotid gland cystadenolymphoma (Warthin's tumour)

The aetiopathogenesis of cystadenolymphoma is mostly unknown. Cystadenolymphomas have a significantly higher incidence in the male than the female population. This might be as a result of endocrine dependency in this kind of tumour. The purpose of the present study was to determine the sex hormone receptor status in cystadenolymphoma. Tissue samples of cystadenolymphoma, pleomorphic adenoma and normal samples of the parotid gland were examined immunohistochemically for oestrogen and progesterone receptors. Progesterone-positive cells could be found in the salivary duct system of normal glands and in the epithelial components of cystadenolymphomas. There was no evidence for the presence of oestrogen receptor in any sample studied. The evidence of progesterone receptors in cystadenolymphoma may implicate a potential role of endocrine factors in the development of this tumour.

Detection of damage to the mitochondrial genome in the oncocytic cells of Warthin's tumour

Warthin's tumour of the salivary glands is composed of oncocytic cells containing excessive numbers of mitochondria which show frequent structural abnormalities and reduced metabolic function. Recent evidence of a strong association between cigarette smoking and the occurrence of Warthin's tumour prompted this study, to look for evidence of damage to mitochondrial DNA (mtDNA) that could be the result of an increase in oxidative stress; two-colour fluorescence in situ hybridization (FISH) was developed to show the distribution of mitochondria with deleted mtDNA in paraffin wax-embedded material. Approximately 10% of mtDNA bears the 'common' 4977 bp deletion. Using the polymerase chain reaction (PCR), the 4977 bp deletion was further quantified, in Warthin's tumour and age-matched normal parotid control tissue. Whilst the deletion was present in all parotid tissue, its presence was significantly higher in oncocytic tumour cells. In a small number of controls, there was a trend towards higher concentrations of the deletion in smokers.