Evolution of brain MRI during follow-up. At diagnosis, the normal T1-weighted hyperintense signal of the posterior pituitary has disappeared (a). Contrast-enhanced hypothalamic mass after gadolinium infusion ((b) and (c)); compression of third ventricle and thickening of pituitary stalk (b). Comparison of brain MRI (T1 with gadolinium) at diagnosis (M0) (d) and at the end of the first-line therapy (e). MRI showed a significant decrease of the hypothalamic mass but the persistence of contrast enhancement after gadolinium. Brain MRI (T1 after gadolinium infusion) at M30 showing a hypothalamic lesion stable in size and with decreased hypersignal compared to previous MRI (f).