In this study, 15 patients (4 men and 11 women, mean age: 50 +/- 13 years) with unilateral adrenal masses detected on ultrasound (US), Computed Tomography (CT) and/or Magnetic Resonance (MR) studies were submitted to positron emission tomography (PET) with fluorine-18 deoxyglucose (FDG). Histology