Background:
Patients diagnosed with cancer do not have sufficient clinical data for the
management of incidental parotid lesions. We aimed to reveal the importance of randomized parotid
lesions encountered during oncologic F-18 fluorodeoxyglucose positron emission tomography
(FDG PET/CT) imaging in our clinical practice and the diagnostic algorithm of such lesions.
Methods:
We performed a database search of PET/CT records generated from 2009 to 2015 for
“parotid” in reports of patients who underwent PET/CT examination for a known malignancy
elsewhere, or cancer screening.
Results:
Incidental parotid FDG uptake on PET/CT had a prevalence of 1.1%. The incidence of parotid
metastasis in our series was 36.4%, and 75% of them had malign melanoma metastasis. Of
the 11 cases, 5 were of Warthin tumours, and Warthin tumours showed stronger GLUT1 expression
than metastatic parotid lesions.
Conclusion:
In patients with malignancy elsewhere, focal involvement of FDG by the parotid
gland, especially if malignant melanoma or SCC is absent, should not be considered a metastatic
disease without histopathologic confirmation. If parotid disease would change the patient’s treatment
plan and disease stage, the parotid lesion should be evaluated by additional methods, such as
fine needle aspiration biopsy.