[Morphological abnormalities of the pituitary stalk of unknown cause in 4 cases of diabetes insipidus in children].

BACKGROUND

Magnetic resonance imaging (MRI) is the best technique for studying hypothalamic and hypophyseal structures.

CASE REPORTS: Four children aged 2 years 5 months to 8 years with idiopathic diabetes insipidus were studied. Their condition had been identified for 2-6 years. All the patients had undergone complete clinical, neurological and endocrinological investigations during the search for the cause of their diabetes insipidus. A CT scan was performed in one patient and MRI in all four; the investigations were repeated each 6 months for 4 years.

RESULTS

The first examination showed complete lack of antidiuretic hormone (four patients) and growth hormone deficiency (two patients). An enlarged pituitary stalk was seen in three patients, one patient had a small anterior pituitary, and three patients gave no posterior pituitary hypersignal. Follow-up showed that three patients completely lacked of growth hormone. One was thyrotropin deficient, three had persistent enlarged pituitary stalks, three had sub-normal anterior pituitaries and all four patients produced no post-pituitary hypersignal. None of the patients developed signs of histiocytosis or germinoma.

CONCLUSION

The finding of abnormal pituitary stalks by MRI raises the possibility that the apparently idiopathic diabetes insipidus is due to some type of infiltrating disease of the hypothalamus and pituitary.