Diabetes Insipidus as a Primary Clinical Manifestation of Lymphocytic Hypophysitis in a Postmenopausal Woman

Lymphocytic hypophysitis is a rare inflammatory disease of the pituitary gland that is characterized by a chronic lymphocytic infiltration of the anterior and/or posterior pituitary gland. Inflammatory lesions of the adenohypophysis occur predominantly in young women and usually are accompanied by some degree of hypopituitarism. The coexistence of diabetes insipidus with this disorder is very uncommon. We report a case of lymphocytic hypophysitis in a menopausal woman presenting with diabetes insipidus as a primary manifestation in which the endocrinologic evaluation of the anterior pituitary showed only a blunted response of growth hormone to hypoglycemic stress and slight hyperprolactinemia. The radiologic study by means of MRI revealed an enlargement of the anterior pituitary with a loss of hyperintense posterior lobe signal and a thickened pituitary stalk. We comment on the different pathologic mechanisms of the development of diabetes insipidus in lymphocytic hypophysitis. The Endocrinologist 2000; 10: 127-130