How common are pituitary adenomas
Pituitary adenomas are benign, monoclonal neoplasms of anterior pituitary cells. A pituitary incidentaloma is a previously unsuspected pituitary lesion that is detected on radiography performed for an unrelated reason. The prevalence of adenomas varies by detection method, including: ≈ 10% by autopsy series and ≈ 20% in radiographic series. Most incidentalomas are microadenomas (> 90%). Despite the prevalence of pituitary adenomas, clinically-evident pituitary disease is less common, estimated at ≈ 80 to 100 cases per 100,000 persons.
In most epidemiologic studies, nonfunctioning adenomas are the second most common adenoma type after prolactinomas.