MaryBeth Pereira, MD, Assistant Resident in Medicine, the Jewish Hospital of St Louis: A 43-year-old man was admitted to the hospital for the evaluation of syncope. His illness began approximately 12 months before admission, when he began to experience recurrent episodes of light-headedness. Four months before admission, he decided to seek medical attention, and arrangements for an oral glucose tolerance test were made. On the way to this test, he became light-headed, which resulted in an automobile accident. When he was examined at a nearby emergency room, a random blood glucose level was noted to be 40 mg/dL. He received a hypoglycemic diet, which consisted of frequent small feedings, but no further diagnostic workup was obtained. Two months before admission, he suffered an episode of complete loss of consciousness, which motivated him to seek additional medical advice. During the preceding six months, he had gained 7 kg, but he denied