Assessment of incidental and clinically unsuspected fluorodeoxyglucose-avid foci detected on oncological positron emission tomography/CT

•. Clinically unsuspected foci of abnormal fluorodeoxyglucose (FDG) uptake are often detected on positron emission tomography (PET)/CT, which without careful assessment may be interpreted as metastatic disease, given the background of pre-existing malignancy in these patients.•. Knowledge of physiological distribution of patterns of FDG is essential to avoid confusing normal uptake with pathological causes.•. As a marker of increased tissue metabolism, FDG uptake accompanies a wide variety of benign reactive/inflammatory conditions that can mimic malignancy; interpretation of findings in the light of the clinical picture helps to minimise this possibility.•. Close correlation with the anatomical information provided by the CT component of the study and comparison of the intensity of uptake of primary and suspected secondary lesions will help to maximise diagnostic accuracy.Clinically unsuspected foci of abnormal fluorodeoxyglucose (FDG) uptake are often detected on positron emission tomography (PET)/CT, w...