Heterotopic salivary duct inclusions in Warthin tumor - A cryptic histological finding involved in its pathogenesis.

Warthin tumor (WT) is the second most common benign parotid gland tumor after pleomorphic adenoma. WT is characterized by cystic and papillary proliferation of a two-layered oncocytic epithelium supported by lymphoid tissue. Heterotopic salivary duct inclusions (SDIs) are frequently observed in lymph nodes (LNs) of WT (SDI/LNs), and are thought to be the origin of WT. If this is true, SDIs should also persist in the lymphoid tissue of WT itself (SDI/WT), as a missing link between SDIs and WTs, but studies of this issue are limited. From 2008-2023, 138 WT cases were surgically excised at our hospital. SDI/LNs and SDI/WTs were histologically examined. Of 100 WT cases with LNs, SDI/LNs were observed in 67 cases (67 %). SDI/WTs were detected in 114 of 138 cases (82.6 %), including 107 of 127 smokers (84.3 %) and 7 of 11 never-smokers (63.6 %). SDI/WTs were located mainly in the subcapsular lymphoid tissue and often surrounded by a fibrous coat resembling salivary excretory ducts. This study revealed a high incidence of SDIs in WT itself, strongly supporting the theory that WT develops from heterotopic salivary ducts.

Novel Detection of Pleomorphic Adenomas via Analysis of 68Ga-DOTATOC PET/CT Imaging.

INTRODUCTION: Currently, the diagnosis of salivary gland tumors using imaging techniques is unreliable. METHODS: In this monocentric retrospective study, we examined patients who received a 68Ga-DOTATOC PET/CT and subsequently underwent a salivary gland tumor resection between 1 January 2010 and 31 December 2021. PET/CT image assessment was compared with somatostatin receptor (SSTR) expression and histology. RESULTS: Thirteen patients (five pleomorphic adenoma (PA) and eight other parotid lesions (OPL)) received a 68Ga-DOTATOC PET/CT. Imaging displayed strong focal tracer uptake in all PA except for one with strong tumor to background discrimination. PA revealed higher SUVmax, SUVmean, liver and blood pool quotients than those of Warthin tumors (WT) and of OPL. In comparison to the contralateral parotid, SUVmax (p = 0.02), SUVmean (p = 0.02), liver quotient (p = 0.03) and blood pool quotient (p = 0.03) were all significantly higher. In contrast, WT and OPL showed in relation to the contralateral parotid no significant differences of SUVmax (WT p = 0.79; OPL p = 0.11), SUVmean (WT p = 1.0; OPL p = 0.08), liver quotient (WT p = 0.5; OPL p = 0.08) and blood pool quotient (WT p = 0.8; OPL p = 0.19). Two PA and one granuloma were not available for examination. In the immunohistochemal analysis, all PA demonstrated the highest intensity of SSTR2 expression (grade 3). Furthermore, PA had a high percentage of cells expressing SSTR2 (20%, 80% and 55%). CONCLUSIONS: A strong tracer uptake in PA was shown in 68Ga-DOTATOC PET/CT. This may allow physicians to utilize radioligated somatostatin analogue PET CT/MR imaging to accurately diagnose PA. Additionally, it may be possible in the future to treat the PA with a noninvasive peptide receptor radionuclide therapy or with somatostatin analogues.

Warthin tumor concomitant with mantle cell lymphoma: a case report and review of literature.

RATIONALE: Warthin tumor (WT) is the second most common benign tumor in salivary gland. It has a slow growth rate and most frequently occurs in the parotid gland. Most patients present with an incidental finding of a painless mass inferior/anterior to the ear. Besides the epithelial component of the tumor, WT is characteristically associated with lymphoid stroma that is considered benign. While there have been a few reports of malignant transformation of the lymphoid components in WT, cases of WT concomitant with mantle cell lymphoma (MCL) are extremely rare. To the best of our knowledge, two cases have been described in the English literature. Herein, we report a case of WT concomitant with MCL in a 70-year-old female patient, and emphasize the importance of careful examination of lymphoid stroma in WT so that concurrent lymphoma is not missed. PATIENT CONCERNS: A 70-year-old Chinese woman with a 40-year history of cigarette smoking presented with a one year history of a right submaxillary mass with recent enlargement. DIAGNOSIS: Cervical ultrasound (US) and computed tomography (CT) scans of the neck revealed a well-circumscribed mass in the right parotid with a maximum diameter of 3.1 cm. Surgical resection of the mass was performed. Histopathological examination revealed a characteristic double-layer of neoplastic epithelium with prominent lymphoid stroma, suggesting WT. In addition, morphology and immunohistochemistry studies confirmed the coexistence of MCL. Thereafter, the final diagnosis of this case was WT concomitant with MCL. INTERVENTIONS: The patient was staged as stage I after clinical assessment. Due to the slow growth of parotid lesions, close observation was decided with periodic clinical and radiological monitoring. OUTCOMES: Currently, the patient demonstrates a stable disease by clinical evaluation. LESSONS: To the best of our knowledge, reported cases of WT concomitant with MCL are very rare. This case highlights the importance of a comprehensive assessment of the lymphoid stroma of WT to avoid missed diagnosis of a lymphoma component in a collision tumor.

Warthin's Tumour as a Parotid Gland Incidentaloma Identified by PET-CT Scan in a Large Series of Cases.

Occasionally in imaging scans there are findings unrelated to the pathology for which the scan was indicated, findings that are called incidentalomas. Warthin tumors have a high glucose avidity, being one of the common incidentalomas in PET-CT scans. The aim of the present study is to analyze the frequency of occurrence of Warthin's tumor as an incidental finding in a large series of patients undergoing 18F-FDG PET-CT. Retrospective analysis of 18F-FDG PET-CT scans performed in our center during the period 2010-2021. Parotid hypermetabolic lesions were identified, as well as their SUVmax, size, smoking habit, BMI (body mass index), and otorhinolaryngology follow-up. 31,423 PET-CT-18FDG studies corresponding to 12,806 patients were analyzed. The frequency of incidentalomas at the parotid level with a diagnosis compatible with Warthin's tumor was 0.87% (n = 111). Eighty percent of the patients with incidentalomas accordant to Warthin's tumor had a history of tobacco use. The highest percentage of incidentalomas compatible with a Warthin tumor was found in patients in whom the indication for PET-CT was the study of a lung carcinoma (1.44%). Only 37% of patients with a PET-CT lesion compatible with a Warthin's tumor were referred for evaluation by the Otorhinolaryngology service. The incidence of Warthin's tumor in 18-FDG PET-CT scans in our center was 0.87%.

Could Obesity Be Related to the Increasing Incidence of Warthin Tumors?

Background: The number of patients diagnosed with Warthin tumors (WTs) has increased significantly in recent years. The association of obesity as measured by body mass index (BMI) with the incidence of WTs remains unclear. This retrospective study aims to compare the BMI and other clinical factors of patients diagnosed with WTs to those with other benign epithelial parotid gland tumors. Methods: Over a 24-year period, 465 cases of benign epithelial parotid gland tumors were treated in our department. Of these, 155 (33.3%) were diagnosed as WTs. The results of the WT group were compared with those of another benign epithelial parotid gland tumor. Results: The mean BMI of WT patients was 27.3, which was significantly higher than in other benign tumors (25.52; p < 0.001). Furthermore, statistically significant correlations were observed, including a higher incidence of WT in males (p < 0.001), in the elderly (p < 0.001), and in cigarette smokers (p < 0.001). Additionally, a higher prevalence of other head and neck cancers was confirmed in patients with WTs (p = 0.004); Conclusions: This study supports the multifactorial etiology of WT development. Among these factors, smoking, advanced age, and obesity have been identified as factors associated with the development of WT, which might be due to chronic inflammation linked to obesity.

The value of T1- and FST2-Weighted-based radiomics nomogram in differentiating pleomorphic adenoma and Warthin tumor.

PURPOSE: To establish a radiomics nomogram based on MRI radiomics features combined with clinical characteristics for distinguishing pleomorphic adenoma (PA) from warthin tumor (WT). METHODS: 294 patients with PA (n = 159) and WT (n = 135) confirmed by histopathology were included in this study between July 2017 and June 2023. Clinical factors including clinical data and MRI features were analyzed to establish clinical model. 10 MRI radiomics features were extracted and selected from T1WI and FS-T2WI, used to establish radiomics model and calculate radiomics scores (Rad-scores). Clinical factors and Rad-scores were combined to serve as crucial parameters for combined model. Through Receiver operator characteristics (ROC) curve and decision curve analysis (DCA), the discriminative values of the three models were qualified and compared, the best-performing combined model was visualized in the form of a radiomics nomogram. RESULTS: The combined model demonstrated excellent discriminative performance for PA and WT in the training set (AUC=0.998) and testing set (AUC=0.993) and performed better compared with the clinical model and radiomics model in the training set (AUC=0.996, 0.952) and testing model (AUC=0.954, 0.849). The DCA showed that the combined model provided more overall clinical usefulness in distinguishing parotid PA from WT than another two models. CONCLUSION: An analytical radiomics nomogram based on MRI radiomics features, incorporating clinical factors, can effectively distinguish between PA and WT.

Case report: The diagnostic pitfall of Warthin-like mucoepidermoid carcinoma.

Warthin-like mucoepidermoid carcinoma (WL-MEC) is a newly reported variant of mucoepidermoid carcinoma. Its histological feature is easy to confused with metaplastic Warthin Tumor, and its relationship with Warthin tumor in histogenesis is controversial. In this study, we presented two cases of WL-MEC, discussing their clinicopathological and molecular features. Notably, one case was initially misdiagnosed during the first onset of the tumor. Case 1 was a 60-year-old female with a mass in the right parotid gland. Case 2 featured a 29-year-old male who developed a lump at the original surgical site 6 months after a "Warthin tumor" resection from the submandibular gland. Histologically, both tumor exhibited a prominent lymphoid stroma and cystic pattern, accompanied by various amounts of epithelial nests composed of squamoid cells, intermediate cells and mucinous cells. The characteristic eosinophilic bilayer epithelium of Warthin tumor was not typically presented in either case. Both cases tested positive for MAML2 gene rearrangement. To contextualize our findings, we conducted a comprehensive review of forty-eight WL-MEC cases documented in the English literature, aiming to synthesizing a reliable differential diagnostic approach. WL-MEC is a rare yet clinically relevant variant, posing a diagnostic pitfall for pathologists. Our study underscores the importance of a meticulous evaluation of both clinical and histological features, coupled with the detection of MAML2 rearrangement, as a credible method for distinguishing WL-MEC from other benign and malignant lesions, particularly metaplastic Warthin tumor.

Uncommon Site Presentation: A Case Report of Extraparotid Warthin's Tumor.

Warthin's tumor, also known as adenolymphoma or papillary cystadenoma lymphomatosum, is a benign tumor almost exclusively found in the parotid gland and is the second most common type of benign parotid tumor. Its manifestation as an extraparotid lesion is rare, with a low incidence in the submandibular gland. In this context, we present a case of Warthin's tumor of the submandibular gland in a 66-year-old man who presented with a painless lateral cystic cervical mass. This case highlights the clinical and radiological evidence of an uncommon extraparotid tumor location, with the diagnosis becoming evident only after the enucleation of the mass. Despite the rarity of extraparotid Warthin's tumor and its potential variation in location, the authors recommend considering Warthin's tumor of the submandibular gland in the differential when assessing lateral cervical masses.

Tumor-to-Tumor Metastasis: Dissemination of Cutaneous Squamous Cell Carcinoma Involving Parotid Warthin Tumor-Case Report.

Warthin tumors (WTs) are the second most common salivary gland tumors, most commonly found in the tail of the parotid gland. The lymphoid components of a WT may also serve as a site for tumor-to-tumor metastasis. This report describes the metastasis of cutaneous squamous cell carcinoma (cSCC) from the preauricular region to a parotid WT. A 68-year-old male patient was admitted to the Department of Cranio-Maxillofacial Surgery of the Jagiellonian University in Cracow, Poland, with a two-year history of a growing, painless skin tumor of the right preauricular region. The patient was eligible for surgical treatment with elective neck dissection at the Va, III, II, I levels with parotidectomy and the excision of the cSCC. In the histopathological examination of the components of the surgical specimen beside the primary cutaneous squamous cell carcinoma (cSCC), a parotid WT was found; in the majority, it was occupied and destroyed by the metastatic cSCC and radically removed. After a tumor board consultation, due to the advanced stage (pT3N2b LVI2 PNI0 R0), with three intraparotid lymph node metastases and LVI2, the patient was authorized for postoperative radiotherapy. In conclusion, tumor-to-tumor metastasis is an extremely rare entity. Surgery is the standard of care for both WTs and head and neck cSCC. In most cases, metastasis into the parotid gland can be successfully treated with superficial parotidectomy with facial nerve preservation. Dissemination into the parotid gland requires elective neck dissection, as well as adjuvant treatment.