A case of reversed pituitary dysfunction with intrasellar mass.

Hypopituitarism can be caused by tumor, inflammation, granuloma and injuries. Once pituitary function is disturbed, hormone replacement therapy is necessary for the remaining life span in most cases. We have experienced a rare case of a unique intrasellar mass associated with pituitary dysfunction in which both spontaneously reversed. A 61-yr-old woman developed hypoadrenalism and central diabetes insipidus (cDI). Magnetic resonance (MR) imaging revealed a lobular, strong hypointense lesion with spotty signal in the middle of the hypophysis. This spotty lesion showed isointensity on T1- and high-intensity on T2-weighted MR images. The spotty signal as well as the normal pituitary lobe were enhanced by the administration of gadolinium. As replacement therapies for hypoadrenalism and cDI, 10 mg of hydrocortisone and 2.5 microg of desmopressin acetate were prescribed. Three months later, slight shrinkage of intrasellar mass and spontaneous improvement of pituitary functions were found. Hydrocortisone was then discontinued. Furthermore, because polyuria and polydipsia were improved nine months later, desmopressin acetate was stopped. Currently, the intrasellar mass continues to shrink, and the patient shows no symptoms without medication. Based upon the unique features of MR images, we suspect that the origin of the mass is an intrasellar hemangioma.