Large adrenal mass heralding the diagnosis of occult extra-adrenal malignancy in two patients.

We report two cases highlighting the role of fluorine-18-fluorodeoxyglucose positron emission tomography/computerised tomography (18F FDG PET/CT) in the diagnostic and preoperative workup of indeterminate adrenal masses. Case 1: a 60-year-old man was diagnosed with a large left-sided adrenal mass with indeterminate radiological characteristics on CT. Biochemical investigations ruled out tumour hypersecretion. 18F FDG PET/CT was performed to exclude metastases and identified a pulmonary nodule in the left upper lobe. Histology of the resected adrenal tumour demonstrated a secondary metastasis from an adenocarcinoma of the lung. Case 2: an 88-year-old male was found to have a heterogeneous and vascular left-sided suprarenal mass and a smaller right-sided adrenal nodule. Both adrenal nodules had indeterminate radiological characteristics. Biochemical investigations were negative. PET/CT demonstrated high avidity in the bilateral adrenal nodules but no extra-adrenal FDG avid disease. Histology demonstrated a metastatic carcinoma of pulmonary origin.