Typically benign, slow-growing tumors that arise from cells in the pituitary gland
- Pituitary adenomas have been identified as the third most frequent intracranial tumor; accounts for 10–25%, at times identified incidentally on magnetic resonance imaging (MRI)
- 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
- Predominant age: Age increases incidence.
- Predominant sex: female > male (3:2) for microadenomas (often delayed diagnosis in men)
- Autopsy studies have found microadenomas in 3–27% and macroadenomas in <0.5% of people without any pituitary disorders.
- MRI scans illustrate abnormalities consistent with pituitary adenoma in 1/10 persons.
- 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 prolactinomas or inhibited dopaminergic suppression by stalk effect
- Carney complex
- 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)
- McCune-Albright syndrome
- Multiple endocrine neoplasia type 1 (MEN1)
- MEN1-like phenotype (MEN4): germline mutation in the cyclin-dependent kinase inhibitor 1B (CDKN1B) (2)
- Gs-alpha (Gsα): an activating mutation of the guanine nucleotide stimulatory protein (Gsα) gene found in ~40% of somatotroph adenomas (3)
Multiple endocrine neoplasias
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Domino, Frank J., et al., editors. "Pituitary Adenoma." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2020. www.unboundmedicine.com/5minute/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; 2020. https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/1688811/all/Pituitary_Adenoma. Accessed June 3, 2023.
Pituitary Adenoma. (2020). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (27th ed.). Wolters Kluwer. https://www.unboundmedicine.com/5minute/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; 2020. [cited 2023 June 03]. Available from: https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/1688811/all/Pituitary_Adenoma.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC 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://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/1688811/all/Pituitary_Adenoma PB - Wolters Kluwer ET - 27 DB - 5-Minute Clinical Consult DP - Unbound Medicine ER -