Pituitary adenomas are histologically the second most common intracranial neoplasm. The most frequently reported histology overall is meningioma (39.0%), followed by tumours of the pituitary (17.1%) and glioblastoma (14.3%).[15]Ostrom QT, Cioffi G, Waite K, et al. CBTRUS statistical report: primary brain and other central nervous system tumors diagnosed in the United States in 2014-2018. Neuro Oncol. 2021 Oct 5;23(12 suppl 2):iii1-105.
https://academic.oup.com/neuro-oncology/article/23/Supplement_3/iii1/6381476
http://www.ncbi.nlm.nih.gov/pubmed/34608945?tool=bestpractice.com
The incidence of histologically confirmed pituitary adenoma in the US is 3.23 and 3.84 cases per 100,000 per year in males and females, respectively, and in studies from Europe, Canada, and Argentina, the mean incidence is approximately 5.1 cases per 100,000 per year.[16]Daly AF, Beckers A. The epidemiology of pituitary adenomas. Endocrinol Metab Clin North Am. 2020 Sep;49(3):347-55.
http://www.ncbi.nlm.nih.gov/pubmed/32741475?tool=bestpractice.com
Rates are slightly higher in females than in males overall, although the sex disparity varies greatly by age.[17]Miller KD, Ostrom QT, Kruchko C, et al. Brain and other central nervous system tumor statistics, 2021. CA Cancer J Clin. 2021 Sep;71(5):381-406.
https://www.doi.org/10.3322/caac.21693
http://www.ncbi.nlm.nih.gov/pubmed/34427324?tool=bestpractice.com
Pituitary adenomas are diagnosed at a younger age in women than in men owing to the high frequency of prolactinomas detected in females of childbearing age.[16]Daly AF, Beckers A. The epidemiology of pituitary adenomas. Endocrinol Metab Clin North Am. 2020 Sep;49(3):347-55.
http://www.ncbi.nlm.nih.gov/pubmed/32741475?tool=bestpractice.com
In the US, incidence rates of pituitary adenoma are higher in black adults.[17]Miller KD, Ostrom QT, Kruchko C, et al. Brain and other central nervous system tumor statistics, 2021. CA Cancer J Clin. 2021 Sep;71(5):381-406.
https://www.doi.org/10.3322/caac.21693
http://www.ncbi.nlm.nih.gov/pubmed/34427324?tool=bestpractice.com
Autopsy studies demonstrate a prevalence of incidental pituitary masses up to 27%; and cranial imaging by MRI indicates a prevalence of about 10%. The majority (99%) of these pituitary tumors are small and clinically nonfunctional; only 0.4% are macroadenomas.[18]Dekkers OM, Pereira AM, Romijn JA, et al. Treatment and follow-up of clinically nonfunctioning pituitary macroadenomas. J Clin Endocrinol Metab. 2008 Oct;93(10):3717-26.
http://www.ncbi.nlm.nih.gov/pubmed/18682516?tool=bestpractice.com
Clinically nonfunctional pituitary adenomas (CNFPAs) account for 14% to 54% of pituitary adenomas.[8]Ntali G, Wass JA. Epidemiology, clinical presentation and diagnosis of non-functioning pituitary adenomas. Pituitary. 2018 Apr;21(2):111-118.
http://www.ncbi.nlm.nih.gov/pubmed/29368293?tool=bestpractice.com
The estimated incidence is 5.6 cases per million per year.[19]Nielsen EH, Lindholm J, Laurberg P, et al. Nonfunctioning pituitary adenoma: incidence, causes of death and quality of life in relation to pituitary function. Pituitary. 2007;10(1):67-73.
http://www.ncbi.nlm.nih.gov/pubmed/17356906?tool=bestpractice.com
They are the second most common form of adenoma, following prolactinomas, in most epidemiological studies.[8]Ntali G, Wass JA. Epidemiology, clinical presentation and diagnosis of non-functioning pituitary adenomas. Pituitary. 2018 Apr;21(2):111-118.
http://www.ncbi.nlm.nih.gov/pubmed/29368293?tool=bestpractice.com