Introduction CHILDREN who show a failure to thrive during the first few months or years of life are frequently seen by all pediatricians. In many cases, the underlying pathology is related to one of a variety of relatively uncommon diseases. Among these are the malabsorption syndromes, errors of metabolic function, fibrocystic disease, infection, and other systemic diseases. Occasionally, however, a child suffering from inanition is seen in which none of these disease processes can be incriminated. The world's literature now contains 24 cases of severe malnutrition in children who later proved to have neoplasms in the region of the anterior hypothalamus; the so-called diencephalic syndrome of infancy.1-8 This syndrome was first described in 1951 by Russell when five cases were reported.6 The same author added five more cases in a subsequent report in 1957.7 Since that time, 14 other cases have been reported throughout the world. The