Incidental finding of focal FDG uptake in the bowel during PET/CT: CT features and correlation with histopathologic results.
OBJECTIVE
The purpose of this study was to identify and characterize the clinically significant lesions associated with incidental detection of focal uptake of (18)F-FDG in the bowel at PET/CT.


METHODS
Among 2,250 consecutively registered patients with various nongastrointestinal malignant diseases who underwent FDG PET/CT as part of their care, patients with the incidental finding of focal bowel uptake of FDG were included in the study. All patients underwent an endoscopic or surgical procedure for characterization of the lesions. The location, intensity of uptake, and appearance of the lesions on PET/CT images were recorded and compared with the endoscopic and surgical pathologic results.


RESULTS
Twenty-one of 25 foci of intense uptake in the bowel were associated with endoscopic or surgical abnormalities (positive predictive value, 84%). Seven lesions were malignant (two primary, five secondary); 13 were premalignant (nine tubovillous adenoma, four tubular adenoma); and one lesion was benign (hyperplastic polyp). Eleven lesions detected with endoscopy were not FDG avid, and all 11 were smaller than 1 cm in diameter. There was no statistically significant difference in the maximum standardized uptake values of the benign and malignant lesions.


CONCLUSIONS
The incidental finding of focal FDG uptake in the bowel justifies further investigation of these foci and should not be dismissed as physiologic uptake. Premalignant lesions, such as adenoma, are often found, and early treatment may prevent the development of carcinoma.
Kei
Pin Lin
PL
Department of Nuclear Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA. Kei.pin.lin@sgh.com.sg
Vikram
Raghunandan
R
Yeung
Henry W D
HW
Stroehlein
John R
JR
Macapinlac
Homer A
HA
D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D015994:Incidence; D033162:Incidental Findings; D007410:Intestinal Diseases / Q000175:diagnosis* / Q000453:epidemiology* / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013382:Subtraction Technique / Q000706:statistics & numerical data*; D013781:Texas; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D055815:Young Adult
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18