[Diabetes insipidus and Langerhans-cell histiocytosis without changes in cerebral CAT and NMR]

In LCH extended disease CNS involvement in is not infrequent. Diabetes insipidus, due to the affectation of hypothalamus-hypophysis axis, is its most frequent finding. The solitary affectation of hypothalamus-hypophysis axis is exceptional. At times, it's a difficult diagnosis and could precede the diagnosis of LCH several years. Usually, CAT and NMR show morphologic lesions. We report a patient who was diagnosed of idiopathic diabetes insipidus when he was 16 years old. Seven year later, he was diagnosed of LCH after underwent a bone marrow biopsy examination, just when the disease involved the bone and lung. Cerebral CAT and NMR didn't show morphologic lesions. In the presence of morphologic lesions in hypothalamus and/or hypophysis, proved by cerebral CAT and NMR, or a clinical setting of DI, the possibility of LCH must be considered.