• Disease Overview
  • Synonyms
  • Signs & Symptoms
  • Causes
  • Affected Populations
  • Disorders with Similar Symptoms
  • Diagnosis
  • Standard Therapies
  • Clinical Trials and Studies
  • References
  • Programs & Resources
  • Complete Report



Last updated: February 09, 2017
Years published: 1986, 1989, 1994, 2003, 2008, 2012, 2017


NORD gratefully acknowledges the Pituitary Network Association and Georgiana Alina Dobri, MD, Assistant Professor of Neuro-Endocrinology in Clinical Neurological Surgery, Weill Cornell Medical College, Cornell University, for assistance in the preparation of this report.

Disease Overview

A prolactinoma is a benign tumor of the pituitary gland (adenoma) that produces an excessive amount of the hormone prolactin. In women, hyperprolactinemia is characterized by irregular menstrual periods or even absence of periods, infertility and production of breast milk in women who are not pregnant (galactorrhea). The most common symptom in men is impotence.

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  • amenorrhea-galactorrhea, nonpuerperal
  • Forbes-Albright syndrome
  • galactorrhea-amenorrhea syndrome
  • nonpuerperal galactorrhea
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Signs & Symptoms

Many of the symptoms of prolactinoma are caused by an excessive amount of prolactin in the blood (hyperprolactinemia) which decreases the ovarian and testicular function. In women, prolactinoma is characterized by irregular menstrual periods, infertility and production of breast milk in women who are not pregnant (galactorrhea). Some women experience diminished sexual desire or painful intercourse. The most common symptom in men is impotence, with Infertility and decreased muscle power being of concern. Both genders can develop low bone mass (osteopenia to osteoporosis).

Some symptoms such as headaches and vision abnormalities are caused by pressure from the pituitary tumor on other tissues and the optic chiasm.

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The cause of pituitary tumors is unknown. Most pituitary tumors are sporadic and not associated with genetic factors that are inherited or can be passed on to children.

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Affected populations

Pituitary tumors that produce enough prolactin to affect health occur in approximately 14 out of 100,000 people.

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All patients who are shown to have a pituitary adenoma on MRI or CT imaging should have a serum prolactin level checked and if their prolactin level is >150-200 ng/ml the patient likely harbors a prolactin secreting tumor which should be treated with a dopamine agonist medication rather than surgery. If the level is less, this could be due to a tumor <10 mm or lack of normal inhibition by hypothalamic dopamine which then permits the normal prolactin secreting cells to hypersecrete (stalk effect). The effect of certain medications, recreational drugs, macroprolactin (big prolactin molecule with no effect on the body), other medical conditions (like low thyroid function, hepatic or renal insufficiency) should be evaluated for these lower levels. A specialist consultation should be considered for such patients by an experienced endocrinologist.

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Standard Therapies

Prolactinoma is treated with medications that act like dopamine (dopamine agonists) such as bromocriptine, quinagolide and cabergoline because dopamine inhibits prolactin secretion. These medications reduce the size of the tumor and reduce the amount of prolactin secretion in approximately 80-90% of patients. Surgery may be recommended if medical therapy is not effective or bothersome side effects (dizziness, mental fogginess, nausea, vomiting). For both medical therapy and surgery, cure rates depend on the size and location of the tumor and the prolactinoma can recur in some affected individuals. Radiation therapy is sometimes used to control growth of a prolactinoma if no response to medications and not amenable to surgery.

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Clinical Trials and Studies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov . All studies receiving U.S. Government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

Some current clinical trials also are posted on the following page on the NORD website:

For information about clinical trials sponsored by private sources, contact:

For information about clinical trials conducted in Europe, contact:

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Lippi G, Plebani M. Macroprolactin: Searching for a Needle in a Haystack?, Clin Chem Lab Med. 2016 Apr;54(4):519-22.

Vilar L, Bronstein M, Diagnosis and management of hyperprolactinemia: Results of a Brazilian multicenter study with 1234 patients. J. Endocrinol. Invest. 2008 May;31(5):436-44.

Kreutzer J, Buchfelder M, Operative treatment of prolactinomas: indications and results in a current consecutive series of 212 patients. European Journal of endocrinology 2008 Jan;158(1):11-8.

Schlechte JA. Long-term management of prolactinomas. J Clin Endocrinol Metab. 2007;92(8):2861-5.

Valdemarsson S. Macroprolactinemia. Risk of misdiagnosis and mismanagement in hyperprolactinemia. Lakartidningen. 2004;101(6):458-65.

Serri O, Chik CL, Ur E, Ezzat S. Diagnosis and management of hyperprolactinemia. CMAJ. 2003;169(6):575-81.

Biller BM, Luciano A, Crosignani PG, et al. Guidelines for the diagnosis and treatment of hyperprolactinemia. J Reprod Med. 1999;44(12 Suppl):1075-84.

Conner P, Fried G. Hyperprolactinemia; etiology, diagnosis and treatment alternatives. Acta Obstet Gynecol Scand. 1998;77(3):249-62.

Davies PH. Drug-related hyperprolactinaemia. Adverse Drug React Toxicol Rev. 1997;16(2):83-94.

Tsang RW, Simpson WJ, Role of radiation therapy in clinical hormonally-active pituitary adenomas, Radiother. Oncol. 1996 Oct;41(1):45-53.

Blackwell RE. Hyperprolactinemia. Evaluation and management. Endocrinol Metab Clin North Am. 1992;21(1):105-24.

Prolactinoma. National Endocrine and Metabolic Diseases Information Service. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Last Update April 2012. https://endocrine.niddk.nih.gov/pubs/prolact/prolact.aspx Accessed February 9, 2017.

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Programs & Resources

RareCare® Assistance Programs

NORD strives to open new assistance programs as funding allows. If we don’t have a program for you now, please continue to check back with us.

Additional Assistance Programs

MedicAlert Assistance Program

NORD and MedicAlert Foundation have teamed up on a new program to provide protection to rare disease patients in emergency situations.

Learn more https://rarediseases.org/patient-assistance-programs/medicalert-assistance-program/

Rare Disease Educational Support Program

Ensuring that patients and caregivers are armed with the tools they need to live their best lives while managing their rare condition is a vital part of NORD’s mission.

Learn more https://rarediseases.org/patient-assistance-programs/rare-disease-educational-support/

Rare Caregiver Respite Program

This first-of-its-kind assistance program is designed for caregivers of a child or adult diagnosed with a rare disorder.

Learn more https://rarediseases.org/patient-assistance-programs/caregiver-respite/

Patient Organizations

National Organization for Rare Disorders