Pituitary Adenoma
Basics
Description
Typically benign, slow-growing tumors that arise from cells in the pituitary gland
- Presenting symptoms include neurologic deficits, visual changes including diplopia, and headaches.
- Subtypes (hormonal): prolactinoma (PRL) 25–40%, nonfunctioning pituitary adenomas 30%, somatotroph adenoma (growth hormone [GH]) 15–20%, corticotroph adenoma (adrenocorticotropic hormone [ACTH]) 5–10%, thyrotroph adenoma (thyroid-stimulating hormone [TSH]) <1%, gonadotropinoma (luteinizing hormone/follicle-stimulating hormone [LH/FSH]), mixed (1)[A]
- Defined as microadenoma <10 mm and macroadenoma ≥10 mm
- May secrete hormones and/or cause mass effects or visual changes
Epidemiology
Incidence
- Autopsy studies have found microadenomas in 3–27% and macroadenomas in <0.5% of people without any pituitary disorders.
- Clinically apparent pituitary tumors are seen in 18/100,000 persons.
Etiology and Pathophysiology
- Monoclonal adenohypophysial cell growth
- Hormonal effects of functional microadenomas often prompt diagnosis before mass effect.
- PRL increased by functional PRLs or inhibited dopaminergic suppression by stalk effect
Genetics
Familial isolated pituitary adenomas: ~15% have mutations in the aryl hydrocarbon receptor–interacting protein gene (AIP); present at a younger age and are larger in size (2)
Risk Factors
Multiple endocrine neoplasias
Commonly Associated Conditions
- McCune-Albright syndrome
- Multiple endocrine neoplasia type 1 (MEN1)
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Citation
Domino, Frank J., et al., editors. "Pituitary Adenoma." 5-Minute Clinical Consult, 33rd ed., Wolters Kluwer, 2025. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688811/all/Pituitary_Adenoma.
Pituitary Adenoma. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2025. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688811/all/Pituitary_Adenoma. Accessed October 3, 2024.
Pituitary Adenoma. (2025). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (33rd ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688811/all/Pituitary_Adenoma
Pituitary Adenoma [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2025. [cited 2024 October 03]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688811/all/Pituitary_Adenoma.
* Article titles in AMA citation format should be in sentence-case
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T1 - Pituitary Adenoma
ID - 1688811
ED - Domino,Frank J,
ED - Baldor,Robert A,
ED - Golding,Jeremy,
ED - Stephens,Mark B,
BT - 5-Minute Clinical Consult, Updating
UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688811/all/Pituitary_Adenoma
PB - Wolters Kluwer
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DP - Unbound Medicine
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