The purpose of this study was to assess the usefulness of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) when differentiating benign from metastatic adrenal masses in patients with bronchogenic carcinoma.For our prospective study, any patient presenting to our institution with pathologically proven bronchogenic carcinoma and an adrenal mass was eligible. Thirty-three adrenal masses (mean size, 3 cm; range, 1-9 cm) in 27 patients were revealed by CT. PET was performed in all 27 patients and interpreted as positive when FDG uptake in the adrenal mass was greater than background activity or negative when FDG uptake in the adrenal mass was equal to or less than background activity. In addition, semiquantitative analysis was performed by computing a standardized uptake ratio. All studies were reviewed independently by three radiologists and then correlated with biopsy and CT findings. Specificity and sensitivity for determining metastatic disease to the adrenal gland were calculated.FDG u...