[Autoimmune hypophysitis--two case reports]

Two young female patients presented with polyuria and polydipsia. In one patient we additionally found idiopathic vitiligo, there were no relevant previous diseases. The gynaecological history was unremarkable.

In both cases a water deprivation test confirmed the diagnosis of central diabetes insipidus, the MRI investigation of the pituitary region showed a prominent and thickened pituitary stalk.

After exclusion of a systemic granulomatous inflammation we diagnosed an autoimmune hypophysitis based on the typical morphological lesions of the pituitary gland and stalk. TREATMENT AND FOLLOW-UP: High-dose glucocorticoid therapy was without any beneficial effect on the central diabetes insipidus. Desmopressin treatment was initiated and led to a normalization of the pre-existing polyuria and polydipsia.

Autoimmune hypophysitis is a very rare disease and the diagnosis is mostly achieved by excluding other causes. Systematic evaluations on large patient cohorts are lacking in the literature with respect to diagnostic procedures, therapy and outcome, the existing knowledge and experience is largely based on case reports. For this reason it appears desirable to create a central register to collect and to evaluate the course of disease in patients with autoimmune hypophysitis.