IMAGING OF GIANT PITUITARY-ADENOMAS

We present five proven giant pituitary adenomas studied by CT and MRI, and review the clinical and imaging findings. Our aim was to examine the radiologic appearances and to search for criteria useful in distin guishing these tumors from other sellar and suprasellar tumours, mainl y craniopharyngioma. The main differences from small adenomas were hig h prevalence of macrocysts, a more invasive behaviour and a clinical p icture dominated by mass effect rather than endocrine disturbance. Fac tors supporting the diagnosis of pituitary adenoma in a giant intra- a nd suprasellar mass include: infrasellar extension, absence of calcifi cation and presence of low-signal cysts on T1-weighted images.