A 49-year-old woman presented for investigation of a chronic cough. Computed tomography (CT) demonstrated a 12-mm diameter lobulated mass in the right middle lobe of the lung. There was no evidence of metastases on computed tomography and, particularly, no masses were demonstrated in the adrenal glands. Subsequent bronchoscopic biopsy demonstrated a poorly differentiated adenocarcinoma. A staging F-18 fluorodeoxyglucose positron emission tomography/computed tomography scan revealed uptake in the right middle lobe malignancy and in bilateral adrenal glands. Two weeks later the patient presented to hospital following a syncopal episode. Addison disease was subsequently diagnosed on the basis of hyponatremia, hyperkalemia, and positive antiadrenal antibodies.