Incidental pituitary adenomas.

Because adenomas of the pituitary are present in 10% to 20% of healthy individuals, the finding of incidental sellar lesions on computed tomography scanning or magnetic resonance imaging has become relatively common. Hyperfunctioning of such lesions can be excluded clinically and by hormonal screening. Hypopituitarism must be excluded only in lesions more than 10 mm in diameter. Although most such lesions are pituitary adenomas, other lesions such as craniopharyngiomas, meningiomas, and metastatic disease also must be considered. In the absence of visual field defects or hypothalamic/stalk compression, it may be appropriate to follow these patients with repeat imaging. If tumors enlarge, surgery is indicated.