Adrenal Oncocytoma: An Incidental Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings with Magnetic Resonance Imaging Correlation

A good percentage of adrenal masses in patients with known malignancy may be benign; thus, noninvasive characterization is important in preventing unnecessary biopsy. This case report represents a patient with papillary thyroid carcinoma and known lung metastasis for which she was followed up with whole-body fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) postradioactive iodine therapy. During the follow-up, she had developed an adrenal mass lesion seen by FDG PET/CT and further characterized by magnetic resonance imaging (MRI). This case demonstrates the potential importance of combining the molecular characterization by FDG PET/CT with the data derived from MRI in narrowing the differential diagnosis of an adrenal mass and suggesting the next diagnostic step in reaching the definitive diagnosis.