Last updated: September 5, 2023

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Summarytoggle arrow icon

Gynecomastia is the proliferation of mammary gland tissue in male individuals, including those with Klinefelter syndrome; neonatal gynecomastia manifests in both male and female infants. Gynecomastia is caused by an increased estrogen/testosterone ratio that can be physiological (typically in neonates, during puberty, or in older adults), pathological (e.g., due to medications, liver cirrhosis, chronic kidney disease, estrogen-secreting tumors), or idiopathic. Gynecomastia is a clinical diagnosis confirmed by identifying palpable glandular tissue on physical examination. A medication review should be performed in all patients; drug-induced gynecomastia accounts for 25% of cases. Diagnostics are not routinely recommended for individuals with physiological gynecomastia. Breast imaging may be considered to rule out differential diagnoses or if physical examination findings are inconclusive. Diagnostic workup for pathological gynecomastia should be guided by clinical evaluation and includes laboratory studies to evaluate for chronic diseases (e.g., liver chemistries, renal function tests, thyroid function tests), hypogonadism (e.g., sex hormone profile), or malignancy (e.g., tumor markers, imaging, biopsy). Pathological gynecomastia can usually be managed by treating the underlying cause. Physiological gynecomastia usually regresses spontaneously. Surgery (e.g., nipple-sparing mastectomy) may be considered for pathological gynecomastia unresponsive to treatment of the underlying cause, longstanding gynecomastia, or cosmesis.

Etiologytoggle arrow icon

Gynecomastia is caused by an increased estrogen/testosterone ratio (e.g., elevated estrogen levels, decreased testosterone levels, or both) but can be idiopathic in upto 25% of patients. It is the most common abnormality of the male breast. [2][3][4]

Physiological gynecomastia [2]

  • Neonatal gynecomastia [5]
    • Occurs in ∼ 90% of neonates due to placental transfer of maternal estrogens
    • Gynecomastia is bilateral, sex independent, and spontaneously resolves within a few weeks or months.
  • Pubertal gynecomastia [6]
    • Occurs in ∼ 50% of adolescent boys (typically occurs in patients aged 10–14 years)
    • Caused by pubertal estrogen/androgen imbalance
    • Clinical features
      • Small, mobile, firm plaques of breast tissue in the subareolar region that develop during puberty
      • Can be tender, unilateral/bilateral, and associated with fatty development around the nipple
      • Spontaneously resolves (usually by 17 years of age)
    • Pharmacotherapy or surgery can be considered for persistent pubertal gynecomastia or if symptoms cause significant distress.
  • Senile gynecomastia: occurs in ∼ 50% of men > 50 years

Pathological gynecomastia [2]

Due to estrogen excess

Due to decreased testosterone

Drug-induced [10][11]

Drug-induced gynecomastia accounts for up to 25% of cases. [9][10]

Some Hormones Cause Fulminant Kleavage: Spironolactone, Hormones, Cimetidine, Finasteride, Ketoconazole cause gynecomastia.

Clinical featurestoggle arrow icon

Diagnosticstoggle arrow icon

General principles [2][9][13]

Examine the breasts and testes in all patients with gynecomastia. Expedite further diagnostics (e.g., imaging, biopsies) if malignancy is suspected (e.g., features of breast cancer; testicular mass on palpation or imaging). [9]

Assess all patients with symptom onset in adulthood for pathological gynecomastia, even when an apparent cause has been identified. [13]

Laboratory studies

Routine studies [2]

Suspected hypogonadism

Suspected estrogen-secreting tumors

Elevated hCG, alpha-fetoprotein, and/or dehydroepiandrosterone is suggestive of malignancy. [2][13]

If all laboratory tests are normal, including the hormone profile, gynecomastia is likely idiopathic. [2]


Breast imaging [15]

Breast imaging is not routinely recommended in patients with clinical features consistent with gynecomastia or pseudogynecomastia. [9][15]

Consider routinely screening for breast cancer in all patients with Klinefelter syndrome who present with gynecomastia; these individuals have a significantly higher risk (16–30 times) of breast cancer than those with XY chromosomes. [2]

Breast lesions concerning for malignancy on imaging or physical examination should be urgently biopsied (e.g., core needle biopsy). [9]

Testicular ultrasound

Some guidelines recommend testicular ultrasound for all individuals with gynecomastia; others recommend imaging only in the following cases: [2][9][13]

Neuroimaging [2]

Differential diagnosestoggle arrow icon

The differential diagnoses listed here are not exhaustive.

Treatmenttoggle arrow icon

Pathological gynecomastia [2]

Treat the underlying cause and monitor for regression. Examples include:

Most patients with gynecomastia experience spontaneous regression or respond well to management of the underlying condition. [13]

After discontinuing medications or treating the underlying cause, an observation period is recommended to monitor for regression. Surgery can be considered for patients with persistent gynecomastia. [13]

Physiological and idiopathic gynecomastia [2][9][13]

Watchful waiting can be considered if no pathological cause is suspected and the patient is not disturbed by their symptoms.

  • Reassurance and follow up every 6 months. [2][13]
  • Provide adequate analgesia.
  • Persistent gynecomastia
    • Consider pharmacotherapy for persistent pubertal gynecomastia of recent onset.
    • Consider surgery for long-standing gynecomastia and cosmesis.

Pharmacotherapy [9][13]

Surgery [9][13]

  • Indications (not routinely required ;)
    • Gynecomastia unresponsive to medical therapy or treatment of the underlying cause
    • Long-standing symptomatic gynecomastia
    • Cosmesis
  • Examples

Referencestoggle arrow icon

  1. Braunstein GD. Clinical practice: Gynecomastia. N Engl J Med. 2007; 357 (12): p.1229-37.doi: 10.1056/NEJMcp070677 . | Open in Read by QxMD
  2. Dickson G. Gynecomastia. Am Fam Physician. 2012; 85 (7): p.716-22.
  3. Kanakis GA, Nordkap L, Bang AK, et al. EAA clinical practice guidelines—gynecomastia evaluation and management. Andrology. 2019; 7 (6): p.778-793.doi: 10.1111/andr.12636 . | Open in Read by QxMD
  4. Niell BL, Lourenco AP, Moy L, et al. ACR Appropriateness Criteria® Evaluation of the Symptomatic Male Breast. Journal of the American College of Radiology. 2018; 15 (11): p.S313-S320.doi: 10.1016/j.jacr.2018.09.017 . | Open in Read by QxMD
  5. Johnson RE, Murad MH. Gynecomastia: pathophysiology, evaluation, and management. Mayo Clin Proc. 2009; 84 (11): p.1010-1015.doi: 10.1016/S0025-6196(11)60671-X . | Open in Read by QxMD
  6. Bland KI, Copeland EM, Klimberg VS. The Breast. Elsevier Health Sciences ; 2009
  7. Neonatal Gynaecomastia. Updated: January 1, 2018. Accessed: March 6, 2018.
  8. Lazala C, Saenger P. Pubertal gynecomastia. J Pediatr Endocrinol Metab. 2002; 15 (5): p.553-60.
  9. Sanyal T, Dutta D, Shivprasad K, Ghosh S, Mukhopadhyay S, Chowdhury S. Gynaecomastia as the initial presentation of thyrotoxicosis.. Indian journal of endocrinology and metabolism. 2012; 16 (Suppl 2): p.S352-3.doi: 10.4103/2230-8210.104089 . | Open in Read by QxMD
  10. Thirumavalavan N, Wilken NA, Ramasamy R. Hypogonadism and renal failure: An update.. Indian journal of urology : IJU : journal of the Urological Society of India. ; 31 (2): p.89-93.doi: 10.4103/0970-1591.154297 . | Open in Read by QxMD
  11. Narula HS, Carlson HE. Gynaecomastia—pathophysiology, diagnosis and treatment. Nat. Rev. Endocrinol.. 2014; 10 (11): p.684-698.doi: 10.1038/nrendo.2014.139 . | Open in Read by QxMD
  12. Deepinder F, Braunstein GD. Drug-induced gynecomastia: an evidence-based review. Expert Opin Drug Saf. 2012; 11 (5): p.779-95.doi: 10.1517/14740338.2012.712109 . | Open in Read by QxMD
  13. Drug-Induced Gynecomastia. Updated: January 1, 2013. Accessed: March 7, 2018.
  14. Braunstein GD. Aromatase and gynecomastia.. Endocr Relat Cancer. 1999; 6 (2): p.315-24.
  15. Nguyen C, Kettler MD, Swirsky ME, et al. Male breast disease: pictorial review with radiologic-pathologic correlation. Radiographics. 2013; 33 (3): p.763-79.doi: 10.1148/rg.333125137 . | Open in Read by QxMD
  16. $Contributor Disclosures - Gynecomastia. None of the individuals in control of the content for this article reported relevant financial relationships with ineligible companies. For details, please review our full conflict of interest (COI) policy:.

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