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.
Twelve parotid incidentalomas in 10 consecutive subjects (nine with a known malignancy elsewhere and one presumptively healthy subject) identified by combined 18F-fluorodeoxyglucose whole-body positron emission tomography and computed tomography (18F-FDG PET/CT) were investigated, with the aim of calculating maximum standardized uptake value (SUV(max)) of each FDG-avid focus, and identifying corresponding sonographic and pathologic findings. The results of ultrasound-guided fine-needle aspiration biopsy (FNAB) (n = 9) and core-needle biopsy (CNB) (n = 3) were Warthin tumor in 10 cases, and pleomorphic adenoma and chronic inflammation in one each. SUV(max) was 7.0-21.0 g/mL (average 13.7 g/mL) for Warthin tumor, 6.8 g/mL for pleomorphic adenoma, and 7.3 g/mL for chronic inflammation. Each FDG-avid focus corresponded to ovoid (n = 11) or lobulated (n = 1) hypoechoic mass on grayscale ultrasonography (US) and hypervascular mass, except one with chronic inflammation, on power Doppler (PD) US. Parotid incidentaloma identified by 18F-FDG PET/CT during workup of various malignancies elsewhere does not necessarily signify primary or metastatic malignancy, but indicates a high likelihood of benign lesions, particularly Warthin tumor. Such lesions should be evaluated thoroughly by US and ultrasound-guided FNAB or CNB if parotid disease would change the patient's treatment plan.
Lee
Sang Kwon
SK
Department of Radiology, Dongsan Medical Center, Keimyung University School of Medicine, 194 Dongsan-dong, Jung-gu, Daegu 700-712, South Korea. sklee@dsmc.or.kr
Rho
Byung Hak
BH
Won
Kyoung Sook
KS
D000236:Adenoma / Q000175:diagnosis*; D000368:Aged; D044963:Biopsy, Fine-Needle / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000175:diagnosis*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed / Q000379:methods*; D018608:Ultrasonography, Doppler / Q000379:methods*; D051598:Whole Body Imaging / Q000379:methods
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18