Lymphocytic Hypophysitis with a Long Latent Period from Onset of Central Diabetes Insipidus to Development of Pituitary Enlargement

Abstract

A 61-year-old man presented with central lymphocytic hypophysitis. Initial pituitary MRI imaging was normal, except for loss of the "bright spot" of the posterior lobe. A diagnosis of idiopathic diabetes insipidus was made. Two years later, pituitary gland enlargement with panhypopituitarism was detected. Eight months after commencing a replacement dose of corticosteroid, the pituitary enlargement was reduced in size. These findings resulted in a diagnosis of lymphocytic hypophysitis. In patients with idiopathic diabetes insipidus, it is important to suspect lymphocytic hypophysitis and to perform a long follow-up to repeat endocrinological examinations and pituitary imaging.