A 66-year-old man with a past medical history of hypertension and arthritis was hospitalized and treated for bacterial pneumonia. Chest X-ray revealed a left-sided chest mass. Computed tomography (CT) scan of the chest demonstrated a large heterogeneously enhancing mass occupying most of the left lower lobe and extending to the inferior aspect of the hilum. It measured 16.6 × 12 cm and caused a mild shift of the mediastinum to the right. The patient declined further work-up or surgical resection of the mass. Dermatologic examination was unremarkable at that time. Over the next 5 months, numerous skin lesions erupted on the patient's trunk. He then experienced several syncopal episodes, at which time he was found to be profoundly hypoglycemic. It was suspected that the chest tumor was producing high serum levels of insulin-like growth factor (IGF) resulting in hypoglycemia and syncope. Serum laboratory investigations were significant for glucose of 20 mg/dL (normal, 60–120 mg/dL), IGF-1 of 39 ng/mL (normal, 152–494 ng/mL), IGF-2 of 927 ng/mL (normal, 210–750 ng/mL), and insulin of