Four cases of Warthin’s tumor of the parotid gland detected with FDG PET

Abstract

In the cancer screening with FDG PET for 1,872 medical health club members, high FDG accumulation in the parotid gland was found in four males (age, 57-70 years). Warthin's tumor was confirmed by surgical pathology. The exact mechanism of high FDG accumulation in Warthin's tumor is not yet known. This tumor may be found incidentally during FDG PET studies. When high FDG accumulation is found in the parotid gland, integrated consideration of the results of the physical examination, medical history and 99mTc-pertechnetate scintigraphy makes it possible to differentiate Warthin's tumor from other lesions.

Parotid incidentaloma identified by combined 18F-fluorodeoxyglucose whole-body positron emission tomography and computed tomography: findings at grayscale and power Doppler ultrasonography and ultrasound-guided fine-needle aspiration biopsy or core-needle biopsy

“…c Longitudinal power Doppler sonographic image reveals mild hypervascularity of the mass mas identified by 18 F-FDG PET or PET/CT ranging from 14% to 63% [12,13]. PET also has limited utility for differentiating benign from malignant salivary gland tumors, primarily because of high FDG uptake by some benign salivary gland tumors, especially Warthin tumor [5,6,14,15]. Basu et al [16] reported 25 patients with incidental FDG uptake in the parotid glands: diffuse symmetric in six; diffuse asymmetric in 12; and focal in seven patients.…”

Differential diagnosis of Warthin’s tumor complicated with lung adenocarcinoma by 18F- FDG PET/CT imaging and radioisotope scanning with Tc-99m pertechnetate: A case report and literature review

“…Except the physiological concentration of 18F-FDG, benign lesions with increased FDG uptake are found in more than 25% of the PET/CT studies performed in patients with proven or suspected malignancy, with inflammation being the most common cause [11] . The high FDG uptake in some benign parotid gland tumors, particularly Warthin's tumor, was extensively observed and reported [9,[11][12][13][14] . This tumor may be found incidentally during FDG PET studies.…”

“…This tumor may be found incidentally during FDG PET studies. Horiuchi M et al reported in the cancer screening with FDG PET for 1,872 medical health club members, high FDG accumulation in the parotid gland was found in four males (age, 57-70 years), who were finally diagnosed as Warthin's tumor by surgical pathology [14] . In a retrospective study of seventy-two patients with benign parotid gland tumors (n=52), malignant parotid tumors (n=12), and inflammation (n=8), Malignant parotid tumors showed significantly higher FDG uptake (standard uptake values [SUVs]) than both benign tumors and inflammation, except in Warthin's tumor [9] .…”

“…Considering the notable percentage (6%-24%) of Warthin's tumor in the parotid tumors [1,3,5,6] , the positive 18F-FDG PET/CT imaging of parotid glands, especially when asymmetrical and focal, should be interpreted cautiously with the characterization on the integrated CT and thought as a signal of radioisotope scanning with Tc-99m pertechnetate [9,12,14] and FNA.…”

“…The radioisotope scanning with Tc-99m pertechnetate of Warthin's tumor was positive and strongly recommended to be used to distinguish the Warthin's tumor from other parotid gland tumors [3,5,[8][9][10]12,14] . The technique is well established and involves imaging of the parotid gland in the posterior projection after the intravenous infusion of 5 mCi of the tracer at 60s intervals for 20 min and obtaining final images of the patient after hydration in right lateral and left lateral positions, followed by washout images obtained 3 min after stimulation with orally administered lemon juice or Vitamin C tablet to determine adequacy and symmetry of glandular secretion [3,5,[8][9][10] .…”