RESUMEN
Diencephalic syndrome is a rare cause of failure to thrive in infancy and early childhood. The syndrome is characterized by profound emaciation with normal appetite, loss of cutaneous adipose tissue, hyperactivity, euphoria, and nystagmus. It commonly occurs in association with chiasmatic and hypothalamic gliomas. It has also been described in association with other histologic types. There is the marked increase of serum growth hormone, which may exhibit an inappropriate, even paradoxical response in stimulation test. A male infant of 12 months of age, showed markedly elevated growth hormone but he had failure to thrive findings. Evenly enhanced round mass was seen at suprasella area in brain CT. Its histological findings was "Desmoplastic infantile ganglioglioma", very rare histologic type. Here we report a case of diencephalic syndrome presented by failure to thrive in association with hypothalamic tumors.