Parotid Incidentaloma Identified by Positron Emission/Computed Tomography: When to Consider Diagnoses Other than Warthin Tumor

Abstract

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.

Prevalence and Clinical Implications of Incidentally Detected Parotid Lesions as Blind Spot on Brain MRI: A Single-Center Experience

“…These findings were inconsistent with previous studies regarding symptomatic parotid tumors, which reported pleomorphic adenoma as the most common tumor in the parotid gland [ 21 , 22 ]. However, they are consistent with recent studies suggesting that Warthin tumors were the most frequent benign lesion in asymptomatic parotid lesions [ 16 , 23 ]. Al-Balas et al [ 16 ] reported that more than 50% of the lesions were Warthin tumors, followed by pleomorphic tumors.…”

“…Al-Balas et al [ 16 ] reported that more than 50% of the lesions were Warthin tumors, followed by pleomorphic tumors. Bothe et al [ 23 ] found a similar preponderance of Warthin tumors, constituting 83% of the asymptomatic parotid lesions. Additionally, the difference in the frequency of Warthin tumors between this study and previous studies may be related to the differences in the number of enrolled study patients.…”

Clinicopathological features of incidental parotid lesions

“…This is contrary to the reported frequency of symptomatic parotid tumors in literature with pleomorphic adenoma as the most frequent benign tumor in the parotid gland [ 3 , 14 ]. Bothe et al described similar dominance of Warthin tumor in an asymptomatic parotid lesions case series where 10 out of 12 lesions were reported to be Warthin tumors [ 15 ]. This could be related to slower growth of Warthin tumors, therefore, more likely to remain asymptomatic.…”

Coincidence of Malignant Melanoma and an Incidently Discovered Parotid Mass Presenting a Diagnostic Challenge

“…Warthin tumor, being the second common parotis tumor after pleomorphic adenoma, is the most common parotid incidentaloma particularly among the smokers. 31 In our case, as PET-CT demonstrated an increased pathological uptake both in the parotid mass and adjacent neck lymph nodes, superficial parotidectomy is performed for frozen section evaluation. Even if the parotid mass had been benign in nature, the definitive surgical treatment should have been at least a superficial parotidectomy.…”