Diabetes insipidus and galactorrhea caused by histiocytosis X

A 44-year-old woman with diabetes insipidus of 3 years duration was found to have histiocytosis X. This was based on clinical, radiological and pathological findings consistent with the diagnosis. Furthermore, she developed spontaneous galactorrhea during the course. Endocrine studies of hypothalamic-pituitary function revealed completely impaired secretion of gonadotropin, growth hormone and anti-diuretic hormone, and possible partial impairment of adrenocorticotropic hormone secretion, while thyroid stimulating hormone secretion remained intact. Persistently elevated plasma levels of human prolactin were also demonstrated, which were unaffected by administration of either thyrotropin releasing hormone, l-DOPA or water loading, but suppressed significantly by CB-154, an ergot alkaloid. These results suggest that abnormalities of the patient's endocrine function may be mainly accounted for by a single hypothalamic lesion.