Fluorodeoxyglucose-Positive Warthin Tumor in a Neck Node Mimicking Metastasis in Primary Intraosseous Left Posterior Mandibular Cancer Staging With Positron Emission Tomography/Computed Tomography

Fine needle aspiration as a diagnostic modality for Warthin tumors identified as fluorodeoxyglucose positron emission tomography/computed tomography-positive

Limited evidence exists regarding the 2-deoxy-2-[fluorine-18]-fluoro-D-glucose (FDG) avidity of Warthin tumors, the second most common benign parotid gland tumor. This study aims to clarify this aspect by analyzing patients who underwent FDG positron emission tomography/computed tomography (PET/CT) and quantifying tumor standardized uptake values (SUV). Medical records of 29 patients with fine needle aspiration (FNA)-confirmed Warthin tumors who underwent FDG-PET/CT near the diagnosis of Warthin tumor were reviewed. Key parameters included cancer history, cytologic diagnosis of Warthin tumor, maximum SUV on FDG PET/CT, and tumor localization. Among the cohort, 18 males and 11 females (average age: 67.9 years) were included. Most patients had malignant neoplasms (lung, head and neck, breast, others). One patient had synchronous liver cancer. Three individuals had bilateral Warthin tumors, and three had bifocal tumors, resulting in 35 tumors for analysis. Tumors were located in the parotid gland (28) and vicinity (7). SUVmax for the Warthin tumors ranged from 3.6 to 26.8, with an average SUVmax of 10.1. Warthin tumors exhibit significant and variable FDG accumulation, exceeding expectations and mimicking high-grade malignancies. Awareness of this phenomenon is crucial for accurate staging and timely management. In cases of positive FDG PET/CT uptake in periparotid, perimandibular, and upper jugular areas, FNA is recommended to avoid misinterpretation or delays in management.

Oral Squamous Cell Carcinoma and Warthin Tumour Occurring As Synchronous Tumours: A Report of Two Cases

Oral cancer is a common site of cancer worldwide with oral squamous cell carcinoma (OSCC) comprising the major segment. The risk factors include tobacco and alcohol abuse, betel quid, and areca nut consumption. Warthin tumour (WT), also known as papillary cystadenoma lymphomatosum is a benign tumour of the salivary gland. It is one of the most common benign parotid neoplasms with cigarette smoking and radiation exposure as possible cited etiologic factors. Rarely, two or more histologically distinct neoplasms may occur synchronously. The synchronous occurrence of OSCC and WT is infrequent.

The aim of this case series is to report the incidence rate of synchronous OSCC and WT in our centre between 2010 and 2019 and their socio-demographic, clinical, histopathological features, management, and prognosis and discuss the relevant literature. Out of 143 OSCC cases reported in our centre from the year 2010 to 2019, two had synchronous OSCC and WT with an incidence rate of 1.4%. These two cases occurred in a 63-year-old female and a 68-year-old male both with smoking habits. One OSCC was present in the left buccal mucosa and the other in the right ventral surface of the tongue, whereas the WT in both cases occurred in the tail of the parotid. One patient had a recurrence and died while the other is under follow-up without any recurrence.

These unusual findings of synchronous occurrence of WT at a distant site from the primary tumour may mimic a malignant disease, more likely a metastasis from the primary OSCC, which could further complicate the management of these patients. Therefore, radiologists, head and neck surgeons, and pathologists should be aware of the occurrence of these unusual presentations to avoid overtreatment in such cases.

Parotid incidentalomas: a systematic review

OBJECTIVE

Parotid incidentalomas on fluorodeoxyglucose positron emission tomography/computed tomography imaging are rare. A systematic review was performed to assess their aetiology and association with scanning indication, and to develop an evidence-based algorithm for their management.

METHODS

A literature search was performed on 25 August 2020 using the keywords 'incidentaloma', 'incidental finding', 'parotid', 'parotid gland', 'salivary gland' and 'head and neck'. Articles were reviewed by two authors before their inclusion.

RESULTS

Forty articles were included, totalling 558 incidentalomas. The mean incidence was 0.74 per cent. Lung cancer was the most common imaging indication. The most common aetiologies were cystadenolymphoma, pleomorphic salivary adenoma and metastases. Only cystadenolymphoma (p = 0.015) and pleomorphic salivary adenoma (p = 0.011) were significantly associated with a primary malignancy (lung). The most common further investigations were aspiration cytology, ultrasound imaging and core biopsy, usually prior to parotidectomy.

CONCLUSION

If appropriate, parotid incidentalomas should be followed up with flexible endoscopy, skin examinations, and head and neck examinations. Ultrasound-guided core biopsy provides higher accuracy, avoiding repeat sampling and excision biopsy.

Parotid incidentaloma identified by positron emission/computed tomography: when to consider diagnoses other than warthin tumor

Introduction Parotid gland incidentalomas (PGIs) are unexpected hypermetabolic foci in the parotid region that can be found when scanning with whole-body positron emission/computed tomography (PET/CT). These deposits are most commonly due to benign lesions such as Warthin tumor.

Objective The aim of this study was to determine the prevalence of PGIs identified in PET/CT scans and to assess the role of smoking in their etiology.

Methods We retrospectively reviewed all PET/CT scans performed at our center in search of PGIs and identified smoking status and standardized uptake value (SUVmax) in each case. We also analyzed the database of parotidectomies performed in our department in the previous 10 years and focused on the pathologic diagnosis and the presence or absence of smoking in each case.

Results Sixteen cases of PGIs were found in 4,250 PET/CT scans, accounting for 0.4%. The average SUVmax was 6.5 (range 2.8 to 16). Cytology was performed in five patients; it was benign in four cases and inconclusive in one case. Thirteen patients had a history of smoking. Of the parotidectomies performed in our center with a diagnosis of Warthin tumor, we identified a history of smoking in 93.8% of those patients.

Conclusions The prevalence of PGIs on PET/CT was similar to that reported by other authors. Warthin tumor is frequently diagnosed among PGIs on PET/CT, and it has a strong relationship with smoking. We suggest that a diagnosis other than Warthin tumor should be considered for PGIs in nonsmokers.