DAVID Leonard, MD, Fellow in Endocrinology, Metabolism Division, The Jewish Hospital of St. Louis and Instructor in Medicine, Washington University School of Medicine: This patient is a 26-year-old man with a four- to six-month history of marked diaphoresis and heat intolerance. He had been married for three years, during which time he changed his wedding ring on three separate occasions to larger sizes. During the year prior to his admission to Jewish Hospital, he suffered from repeated bouts of sinusitis and tonsillitis for which he was treated with a variety of decongestants and antibiotics with minimal symptomatic relief. He had also consulted a dentist because of increasing overhang of his lower jaw and increasing space between his teeth. He denied headaches, diplopia, visual difficulties, or loss of libido. After the age of 18 years, he began to develop progressive mandibular enlargement and acromegalic features with overgrowth of the superorbital ridges,