- 0
Highlights & Basics
- Gynecomastia is the proliferation of benign male glandular breast tissue. It may be unilateral or bilateral, painful, or asymptomatic.
- Gynecomastia results from excessive estrogen action or deficient testosterone action on breast glandular tissue.
- Physiologic gynecomastia occurs in the newborn period, during puberty, and with aging and obesity.
- Many drugs, environmental exposures, illnesses, and some genetic conditions increase the risk for gynecomastia. Treatment may improve gynecomastia, especially if it is of recent onset.
- Most cases require no specific treatment. Therapies for persistent pain or psychological distress include anti-estrogen therapy, androgen replacement if proven testosterone deficiency, or surgery (liposuction or mammoplasty).
Quick Reference
History & Exam
Key Factors
Other Factors
Diagnostics Tests
Treatment Options
Definition
Epidemiology
Etiology
Pathophysiology
Images
Histology: gynecomastia; clusters of ducts, halos of edema, fibrous background; 5X magnification
Patient with gynecomastia
Hormones involved in male breast development
Histology: normal male breast; rare, isolated ducts; no lobules; 10X magnification
Histology: normal female breast; many ducts; prominent lobules; 10X magnification
Gynecomastia evaluation
Histology: breast cancer; nests of malignant ductal carcinoma invading tissue; 10X magnification
Citations
Kanakis GA, Nordkap L, Bang AK, et al. EAA clinical practice guidelines-gynecomastia evaluation and management. Andrology. 2019 Nov;7(6):778-93.[Abstract][Full Text]
Bromley HL, Dave R, Lord N, et al. Gynaecomastia: when and why to refer to specialist care. Br J Gen Pract. 2021 Apr;71(705):185-8.[Abstract][Full Text]
Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018 May 1;103(5):1715-44.[Abstract][Full Text]
American College of Radiology. ACR appropriateness criteria: evaluation of the symptomatic male breast. 2018 [internet publication].[Full Text]
Mulhall JP, Trost LW, Brannigan RE, et al. Evaluation and management of testosterone deficiency: AUA guideline. J Urol. 2018 Aug;200(2):423-32.[Abstract][Full Text]
1. Niewoehner CB, Schorer AE. Gynaecomastia and breast cancer in men. BMJ. 2008 Mar 29;336(7646):709-13.[Abstract]
2. Simon BE, Hoffman S, Kahn S. Classification and surgical correction of gynecomastia. Plast Reconstr Surg. 1973 Jan;51(1):48-52.[Abstract]
3. Kanakis GA, Nordkap L, Bang AK, et al. EAA clinical practice guidelines-gynecomastia evaluation and management. Andrology. 2019 Nov;7(6):778-93.[Abstract][Full Text]
4. Narula HS, Carlson HE. Gynaecomastia-pathophysiology, diagnosis and treatment. Nat Rev Endocrinol. 2014 Nov;10(11):684-98.[Abstract]
5. Gossner J. Gynecomastia on computed tomography of the chest -prevalence in a clinical population and an analysis of possible causes. Eur J Breast Health. 2019 Jan;15(1):67-8.[Abstract][Full Text]
6. Aslan Ö, Bayraktaroğlu S, Çinkooğlu A, et al. Prevalence of incidental gynecomastia by chest computed tomography in patients with a prediagnosis of COVID-19 pneumonia. Eur J Breast Health. 2021 Apr;17(2):173-9.[Abstract][Full Text]
7. McKiernan JF, Hull D. Breast development in the newborn. Arch Dis Child. 1981 Jul;56(7):525-9.[Abstract][Full Text]
8. Nydick M, Bustos J, Dale JH Jr, et al. Gynecomastia in adolescent boys. JAMA. 1961 Nov 4;178:449-54.[Abstract]
9. Priskorn L, Nordkap L, Bang AK, et al. Average sperm count remains unchanged despite reduction in maternal smoking: results from a large cross-sectional study with annual investigations over 21 years. Hum Reprod. 2018 Jun 1;33(6):998-1008.[Abstract][Full Text]
10. Nuttall FQ. Gynecomastia as a physical finding in normal men. J Clin Endocrinol Metab. 1979 Feb;48(2):338-40.[Abstract]
11. Niewoehner CB, Nuttall FQ. Gynecomastia in a hospitalized male population. Am J Med. 1984 Oct;77(4):633-8.[Abstract]
12. Anderson JA, Gram JB. Male breast at autopsy. Acta Pathol Microbiol Immunol Scand. 1982 May;90(3):191-7.[Abstract]
13. Georgiadis E, Papandreou L, Evangelopoulou C, et al. Incidence of gynaecomastia in 954 young males and its relationship to somatometric parameters. Ann Hum Biol. 1994 Nov-Dec;21(6):579-87.[Abstract]
14. Ersöz Hö, Onde ME, Terekeci H, et al. Causes of gynaecomastia in young adult males and factors associated with idiopathic gynaecomastia. Int J Androl. 2002 Oct;25(5):312-6.[Abstract][Full Text]
15. Kim MS, Kim JH, Lee KH, et al. Incidental gynecomastia on thoracic computed tomography in clinical practice: characteristics, radiologic features, and correlation with possible causes in South Korean Men. Am J Mens Health. 2020 May-Jun;14(3):1557988320908102.[Abstract][Full Text]
16. Klang E, Kanana N, Grossman A, et al. Quantitative CT assessment of gynecomastia in the general population and in dialysis, cirrhotic, and obese patients. Acad Radiol. 2018 May;25(5):626-35.[Abstract]
17. Winters SJ. Laboratory assessment of testicular function. In: Feingold KR, Anawalt B, Blackman MR, et al, eds. Endotext [Internet]. South Dartmouth (MA): MDText.com; 2000.[Abstract][Full Text]
18. Travison TG, Araujo AB, Kupelian V, et al. The relative contributions of aging, health and lifestyle factors to serum testosterone decline in men. J Clin Endocrinol Metab. 2007 Feb;92(2):549-55.[Abstract][Full Text]
19. Harman SM, Metter EJ, Tobin JD, et al. Longitudinal effects of aging on serum total and free testosterone levels in healthy men. J Clin Endocrinol Metab. 2001 Feb;86(2):724-31.[Abstract][Full Text]
20. Braunstein GD. Gynecomastia. New Engl J Med. 1993 Feb 18;328(7):490-95.[Abstract]
21. Carlson HE. Approach to the patient with gynecomastia. J Clin Endocrinol Metab. 2011 Jan;96(1):15-21.[Abstract][Full Text]
22. Deepinder F, Braunstein GD. Drug-induced gynecomastia: an evidence-based review. Expert Opin Drug Saf. 2012 Sep;11(5):779-95.[Abstract]
23. Nuttall FQ, Warrier RS, Gannon MC. Gynecomastia and drugs: a critical evaluation of the literature. Eur J Clin Pharmacol. 2015 May;71(5):569-78.[Abstract][Full Text]
24. Trinchieri A, Perletti G, Magri V, et al. Drug-induced gynecomastia: a systematic review and meta-analysis of randomized clinical trials. Arch Ital Urol Androl. 2021 Dec 21;93(4):489-96.[Abstract][Full Text]
25. Association of Breast Surgery. Summary statement: investigation and management of gynaecomastia in primary and secondary care. Mar 2021 [internet publication].[Full Text]
26. Shozu M, Sebastian S, Takayama K, et al. Estrogen excess associated with novel gain-of-function mutations affecting the aromatase gene. N Engl J Med. 2003 May 8;348(19):1855-65.[Abstract]
27. Bromley HL, Dave R, Lord N, et al. Gynaecomastia: when and why to refer to specialist care. Br J Gen Pract. 2021 Apr;71(705):185-8.[Abstract][Full Text]
28. Dobs A, Darkes MJ. Incidence and management of gynecomastia in men treated for prostate cancer. J Urol. 2005 Nov;174(5):1737-42.[Abstract]
29. Schulman C, Pommerville P, Hofner K, et al. Long-term therapy with the dual 5alpha-reductase inhibitor dusteride is well tolerated in men with symptomatic benign prostatic hyperplasia. BJU Int. 2006 Jan;97(1):73-9.[Abstract]
30. Jensen RT, Collen MJ, Pandol SJ, et al. Cimetidine-induced impotence and breast changes in patients with gastric hypersecretory states. N Engl J Med. 1983 Apr 14;308(15):883-7.[Abstract]
31. Thompson DF, Carter JR. Drug-induced gynecomastia. Pharmacotherapy. 1993 Jan-Feb;13(1):37-45.[Abstract]
32. Christou MA, Christou PA, Markozannes G, et al. Effects of anabolic androgenic steroids on the reproductive system of athletes and recreational users: a systematic review and meta-analysis. Sports Med. 2017 Sep;47(9):1869-83.[Abstract]
33. Patanè FG, Liberto A, Maria Maglitto AN, et al. Nandrolone decanoate: use, abuse and side effects. Medicina (Kaunas). 2020 Nov 11;56(11):606.[Abstract][Full Text]
34. Fagerlund A, Cormio L, Palangi L, et al. Gynecomastia in patients with prostate cancer: a systematic review. PLoS One. 2015;10(8):e0136094.[Abstract][Full Text]
35. Tangpricha V, den Heijer M. Oestrogen and anti-androgen therapy for transgender women. Lancet Diabetes Endocrinol. 2017 Apr;5(4):291-300.[Abstract]
36. Huffman DH, Kampmann JP, Hignite CE, et al. Gynecomastia induced in normal males by spironolactone. Clin Pharmacol Ther. 1978 Oct;24(4):465-73.[Abstract]
37. Cuculi F, Suter A, Erne P. Spironolactone-induced gynecomastia. CMAJ. 2007 Feb 27;176(5):620.[Abstract][Full Text]
38. Parthasarathy HK, Ménard J, White WB, et al. A double-blind, randomized study comparing the antihypertensive effect of eplerenone and spironolactone in patients with hypertension and evidence of primary aldosteronism. J Hypertens. 2011 May;29(5):980-90.[Abstract]
39. Bagatell CJ, Bremner WJ. Androgens in men: uses and abuses. N Engl J Med. 1996 Mar 14;334(11):707-14.[Abstract]
40. Perry PJ, Lund BC, Deninger MJ, et al. Anabolic steroid use in weight lifters and body builders: an internet survey of drug utilization. Clin J Sport Med. 2005 Sep;15(5):326-30.[Abstract]
41. Friedl KE, Yesalis CE. Self-treatment of gynecomastia in bodybuilders who use anabolic steroids. Physician Sportsmed. 1989 Mar;17(3):67-79.[Abstract]
42. Toorians AW, Bovee TF, De Rooy J, et al. Gynaecomastia linked to the intake of a herbal supplement fortified with diethylstilbestrol. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2010 Jul;27(7):917-25.[Abstract][Full Text]
43. Finkelstein JS, McCully WF, MacLaughlin DT, et al. The mortician's mystery: gynecomastia and reversible hypogonadotropic hypogonadism in an embalmer. N Engl J Med. 1988 Apr 14;318(15):961-5.[Abstract]
44. Harrington JM, Stein GF, Rivera RO, et al. The occupational hazards of formulating oral contraceptives: a survey of plant employees. Arch Environ Health. 1978 Jan-Feb;33(1):12-5.[Abstract]
45. Henley DV, Lipson N, Korach KS, et al. Prepubertal gynecomastia linked to lavender and tea tree oils. N Engl J Med. 2007 Feb 1;356(5):479-85.[Abstract][Full Text]
46. Braunstein EW, Braunstein GD. Are prepubertal gynaecomastia and premature thelarche linked to topical lavender and tea tree oil use? touchREV Endocrinol. 2023 Nov;19(2):60-8.[Abstract][Full Text]
47. Ramsey JT, Li Y, Arao Y, et al. Lavender products associated with premature thelarche and prepubertal gynecomastia: case reports and endocrine-disrupting chemical activities. J Clin Endocrinol Metab. 2019 Nov 1;104(11):5393-405.[Abstract][Full Text]
48. Durmaz E, Özmert EN, Erkekoğlu P, et al. Plasma phthalate levels in pubertal gynecomastia. Pediatrics. 2010 Jan;125(1):e122-9.[Abstract][Full Text]
49. Mohammadnia N, Simsek S, Stam F. Gynecomastia as a presenting symptom of Graves' disease in a 49-year-old man. Endocrinol Diabetes Metab Case Rep. 2021 Apr 1;2021:20-0181.[Abstract][Full Text]
50. Sakulterdkiat T, Romphothong K, Chatchomchuan W, et al. Unilateral gynecomastia as an initial presentation of hyperthyroid Graves' disease. Endocrinol Diabetes Metab Case Rep. 2021 Nov 1;2021:20-0140.[Abstract][Full Text]
51. Cavanaugh J, Niewoehner CB, Nuttall FQ. Gynecomastia and cirrhosis of the liver. Arch Intern Med. 1990 Mar;150(3):563-5.[Abstract]
52. Dobs AS, Meikle AW, Arver S, et al. Pharmacokinetics, efficacy, and safety of a permeation-enhanced testosterone transdermal system in comparison with bi-weekly injections of testosterone enanthate for the treatment of hypogonadal men. J Clin Endocrinol Metab. 1999 Oct;84(10):3469-78.[Abstract][Full Text]
53. Pastuszak AW, Gomez LP, Scovell JM, et al. Comparison of the effects of testosterone gels, injections, and pellets on serum hormones, erythrocytosis, lipids, and prostate-specific antigen. Sex Med. 2015 Sep;3(3):165-73.[Abstract][Full Text]
54. Boccardo F, Rubagotti A, Battaglia M, et al. Evaluation of tamoxifen and anastrozole in the prevention of gynecomastia and breast pain induced by bicalutamide monotherapy of prostate cancer. J Clin Oncol. 2005 Feb 1;23(4):808-15.[Abstract][Full Text]
55. Salzstein D, Sieber P, Morris T, et al. Prevention and management of bicalutamide-induced gynecomastia and breast pain: randomized endocrinologic and clinical studies with tamoxifen and anastrozole. Prostate Cancer Prostatic Dis. 2005;8(1):75-83.[Abstract][Full Text]
56. Fradet Y, Egerdie B, Andersen M, et al. Tamoxifen as prophylaxis for prevention of gynaecomastia and breast pain associated with bicalutamide 150 mg monotherapy in patients with prostate cancer: a randomised, placebo-controlled, dose-response study. Eur Urol. 2007 Jul;52(1):106-14.[Abstract]
57. Viani GA, Bernardes da Silva LG, Stefano EJ. Prevention of gynecomastia and breast pain caused by androgen deprivation therapy in prostate cancer: tamoxifen or radiotherapy? Int J Radiat Oncol Biol Phys. 2012 Jul 15;83(4):e519-24.[Abstract]
58. Kunath F, Keck B, Antes G, et al. Tamoxifen for the management of breast events induced by non-steroidal antiandrogens in patients with prostate cancer: a systematic review. BMC Med. 2012 Aug 28;10:96.[Abstract][Full Text]
59. Tyrrell CJ, Payne H, Tammela TL, et al. Prophylactic breast irradiation with a single dose of electron beam radiotherapy (10 Gy) significantly reduces the incidence of bicalutamide-induced gynecomastia. Int J Rad Oncol Biol Phys. 2004 Oct 1;60(2):476-83.[Abstract]
60. Perdonà S, Autorino R, De Placido S, et al. Efficacy of tamoxifen and radiotherapy for prevention and treatment of gynecomastia and breast pain caused by bicalutamide in prostate cancer: a randomised controlled trial. Lancet Oncol. 2005 May;6(5):295-300.[Abstract]
61. Braunstein GD. Environmental gynecomastia. Endocr Pract. 2008 May-Jun;14(4):409-11.[Abstract]
62. Felner EI, White PC. Prepubertal gynecomastia: indirect exposure to estrogen cream. Pediatrics. 2000 Apr;105(4):E55.[Abstract]
63. Braunstein GD. Causal relationship between smoking marijuana and gynecomastia remains unproven. Radiology. 2023 Jun;307(5):e223046.[Abstract][Full Text]
64. Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018 May 1;103(5):1715-44.[Abstract][Full Text]
65. American College of Radiology. ACR appropriateness criteria: evaluation of the symptomatic male breast. 2018 [internet publication].[Full Text]
66. Billa E, Kanakis GA, Goulis DG. Imaging in gynecomastia. Andrology. 2021 Sep;9(5):1444-56.[Abstract][Full Text]
67. Evans GF, Anthony T, Turnage RH, et al. The diagnostic accuracy of mammography in the evaluation of male breast disease. Am J Surg. 2001 Feb;181(2):96-100.[Abstract]
68. Yoon B, Chae EY, Cha JH, et al. Male patients with unilateral breast symptoms: an optimal imaging approach. Eur Radiol. 2020 Aug;30(8):4242-50.[Abstract]
69. Janes SE, Lengyel JA, Singh S, et al. Needle core biopsy for the assessment of unilateral breast masses in men. Breast. 2006 Apr;15(2):273-5.[Abstract]
70. Hines SL, Tan WW, Yasrebi M, et al. The role of mammography in male patients with breast symptoms. Mayo Clin Proc. 2007 Mar;82(3):297-300.[Abstract]
71. Executive Committee of American Society of Plastic Surgeons. Practice parameters: gynecomastia. Feb 2004 [internet publication].[Full Text]
72. National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: genetic/familial high-risk assessment: breast, ovarian, and pancreatic [internet publication].[Full Text]
73. American College of Radiology. ACR appropriateness criteria: evaluation of nipple discharge. 2022 [internet publication].[Full Text]
74. Mulhall JP, Trost LW, Brannigan RE, et al. Evaluation and management of testosterone deficiency: AUA guideline. J Urol. 2018 Aug;200(2):423-32.[Abstract][Full Text]
75. European Association of Urology. EAU guidelines on sexual and reproductive health. 2024 [internet publication].[Full Text]
76. Mannu GS, Sudul M, Bettencourt-Silva JH, et al. Role of tamoxifen in idiopathic gynecomastia: A 10-year prospective cohort study. Breast J. 2018 Nov;24(6):1043-5.[Abstract]
77. Ting AC, Chow LW, Leung YF. Comparison of tamoxifen with danazol in the management of idiopathic gynecomastia. Am Surg. 2000 Jan;66(1):38-40.[Abstract]
78. Jones DJ, Holt SD, Surtees P, et al. A comparison of danazol and placebo in the treatment of adult idiopathic gynaecomastia: results of a prospective study in 55 patients. Ann R Coll Surg Engl. 1990 Sep;72(5):296-8.[Abstract][Full Text]
79. Prasetyono TOH, Andromeda I, Budhipramono AG. Approach to gynecomastia and pseudogynecomastia surgical techniques and its outcome: a systematic review. J Plast Reconstr Aesthet Surg. 2022 May;75(5):1704-28.[Abstract]
80. Fagerlund A, Lewin R, Rufolo G, et al. Gynecomastia: a systematic review. J Plast Surg Hand Surg. 2015;49(6):311-8.[Abstract]
81. Brown RH, Chang DK, Siy R, et al. Trends in the surgical correction of gynecomastia. Semin Plast Surg. 2015 May;29(2):122-30.[Abstract]
82. Braunstein GD. Clinical practice: gynecomastia. N Engl J Med. 2007 Sep 20;357(12):1229-37.[Abstract]
83. Vojvodic M, Xu FZ, Cai R, et al. Anabolic-androgenic steroid use among gynecomastia patients: prevalence and relevance to surgical management. Ann Plast Surg. 2019 Sep;83(3):258-63.[Abstract]
84. Ghadjar P, Aebersold DM, Albrecht C, et al. Treatment strategies to prevent and reduce gynecomastia and/or breast pain caused by antiandrogen therapy for prostate cancer: statement from the DEGRO working group prostate cancer. Strahlenther Onkol. 2020 Jul;196(7):589-97.[Abstract][Full Text]
85. Serretta V, Altieri V, Morgia G, et al. A randomized trial comparing tamoxifen therapy vs. tamoxifen prophylaxis in bicalutamide-induced gynecomastia. Clin Genitourin Cancer. 2012 Sep;10(3):174-9.[Abstract]
86. Safran T, Abi-Rafeh J, Alabdulkarim A, et al. Radiotherapy for prevention or management of gynecomastia recurrence: future role for general gynecomastia patients in plastic surgery given current role in management of high-risk prostate cancer patients on anti-androgenic therapy. J Plast Reconstr Aesthet Surg. 2021 Nov;74(11):3128-40.[Abstract]
87. Soliman AT, De Sanctis V, Yassin M. Management of adolescent gynecomastia: an update. Acta Biomed. 2017 Aug 23;88(2):204-13.[Abstract][Full Text]
88. Mieritz MG, Rakêt LL, Hagen CP, et al. A longitudinal study of growth, sex steroids, and IGF-1 in boys with physiological gynecomastia. J Clin Endocrinol Metab. 2015 Oct;100(10):3752-9.[Abstract][Full Text]
89. Lapid O, van Wingerden JJ, Perlemuter L. Tamoxifen therapy for the management of pubertal gynecomastia: a systematic review. J Pediatr Endocrinol Metab. 2013;26(9-10):803-7.[Abstract]
90. Berger O, Landau Z, Talisman R. Gynecomastia: a systematic review of pharmacological treatments. Front Pediatr. 2022;10:978311.[Abstract][Full Text]
91. Nuzzi LC, Firriolo JM, Pike CM, et al. The effect of surgical treatment for gynecomastia on quality of life in adolescents. J Adolesc Health. 2018 Dec;63(6):759-65.[Abstract]
92. Koshy JC, Goldberg JS, Wolfswinkel EM, et al. Breast cancer incidence in adolescent males undergoing subcutaneous mastectomy for gynecomastia: is pathologic examination justified? A retrospective and literature review. Plast Reconstr Surg. 2011 Jan;127(1):1-7.[Abstract]
93. Senger JL, Chandran G, Kanthan R. Is routine pathological evaluation of tissue from gynecomastia necessary? A 15-year retrospective pathological and literature review. Plast Surg (Oakv). 2014 Summer;22(2):112-6.[Abstract][Full Text]
94. Topor LS, Bowerman K, Machan JT, et al. Central precocious puberty in Boston boys: a 10-year single center experience. PLoS One. 2018;13(6):e0199019.[Abstract][Full Text]
95. Cisternino M, Arrigo T, Pasquino AM, et al. Etiology and age incidence of precocious puberty in girls: a multicentric study. J Pediatr Endocrinol Metab. 2000 Jul;13 Suppl 1:695-701.[Abstract]
96. Herbert SL, Ergezinger K, Sauer S, et al. Prepubertal idiopathic unilateral gynecomastia: case report and literature review. Breast Care (Basel). 2022 Dec;17(6):573-9.[Abstract][Full Text]
97. Mameli C, Selvaggio G, Cerini C, et al. Atypical Leydig cell tumor in children: report of 2 cases. Pediatrics. 2016 Nov;138(5):e20160151.[Abstract]
98. Wasniewska M, Raiola G, Galati MC, et al. Non-classical 21-hydroxylase deficiency in boys with prepubertal or pubertal gynecomastia. Eur J Pediatr. 2008 Sep;167(9):1083-4.[Abstract]
99. Zadik Z, Pertzelan A, Kaufman H, et al. Gynaecomastia in two prepubertal boys with congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency. Helv Paediatr Acta. 1979 May;34(2):185-7.[Abstract]
100. Einav-Bachar R, Phillip M, Aurbach-Klipper Y, et al. Prepubertal gynaecomastia: aetiology, course and outcome. Clin Endocrinol. 2004 Jul;61(1):55-60.[Abstract]
101. Tunio MA, Al-Asiri M, Al-Amro A, et al. Optimal prophylactic and definitive therapy for bicalutamide-induced gynecomastia: results of a meta-analysis. Curr Oncol. 2012 Aug;19(4):e280-8.[Abstract][Full Text]
102. Pérez-Luis J, Adolewska PD. ODP412 high frequency of erythrocytosis in hypogonadal men on testosterone replacement therapy. J Endocr Soc. 2022;6(1):A661-2.[Full Text]
103. Thiruchelvam P, Walker JN, Rose K, et al. Gynaecomastia. BMJ. 2016 Sep 22;354:i4833.[Abstract]
