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Breast Surgery


Authors: Mia Demant, MD, Christian Kaare Paaskesen med. student, Hasan Gökcer Tekin, MD, Magnus Balslev Avnstorp, MD and Mia Steffensen, MD


Benign enlargement of the male breast, caused by an increase in ductal tissue, stroma and/or fat. Most frequent due to hormonal changes.


Gynecomastia was first introduced by Galen of Pergamon during the 2nd century AD, the surgical resection was first described by Paulis of Aegina in the 7th century AD. Suction-assisted lipectomy was first performed in the 1980s, and more recently ultrasound-assisted liposuction has been used (1).

The incidence of gynecomastia (GM) is between 25 to 65 percent, depending on selection criteria. It is most commonly seen in hormonal transition phases such as neonatal age, puberty, and the age after 50 years.

GM in adult men can be the first symptom of an underlying disease, and thorough investigation is recommended. Treatment of an underlying cause of GM is the first-line treatment. 

Beside from the physiological causes, the pathological or induced changes can be multiple, including (2):

  • Medical drugs, e.g. antiandrogens (i.e. finasteride), antihypertensive (spironolactone), exogenous hormones (i.e. prednisone), marijuana and gastrointestinal drugs (H2 histamine receptor blockers) {Citation}
  • Pathological hormonal changes i.e. pituitary tumors (prolactinomas) and testis tumors (Leydig and Sertoli cell tumors) (3)
  • Alcohol abuse or overuse via adverse effects on the liver
  • Klinefelter’s syndrome.
  • Kidney disease
  • HIV
  • Cannabis abuse

Differential diagnoses

Many obese people have so-called ‘pseudo-GM’, where adipose tissue is illusory glandular tissue and can even give ptotic breasts.

It is of great importance to distinguish benign GM from a potential breast cancer. Breast cancer in men is a rare disease with approximately 30 cases annually in Denmark (4). The median age of onset is 70 years (10 years later than women’s) and patients, who meet the criteria below should be referred to a breast surgery center in a cancer patient pathway:

  • A suspicious lump in one breast
  • Inverted nipple (new)
  • Indentation of skin (new)
  • Nipple-areola eczema or ulceration (Morbus Paget)
  • Clinically suspicious axillary lymph nodes

Relevant Anatomy

In the case of GM, the male breast poses a pyramidal shape with feminine features. Different from the female breast, male breast tissue contains no lobules and is rather dense. It is placed above the pectoralis major muscle and under the nipple-areolar complex (NAC) in close relation to the adipose tissue (5).

This image has an empty alt attribute; its file name is Gynecomastia1.png
Figure 1 | Cross-section of chest, with and without glandular tissue.


GM is most often caused by increased estrogen activity, decreased testosterone activity or the use of numerous medications. The hormonal imbalance between estrogen and androgen eventually leads to ductal hyperplasia, i.e. glandular tissue proliferation. This can be caused by estrogen-secreting neoplasms, but more commonly are the conversion of androgens to estrogens by tissue aromatase (as occurs in obesity). In Klinefelter’s syndrome, levels of free testosterone are low because of gonadal failure, and conditions like chronic liver disease result in alterations of serum levels of sex hormone-binding globulin, that again disturbs the balance between free testosterone and estrogen. Androgen receptors can also be blocked by certain medications, while estrogen receptors can be activated by others, together with environmental exposures (2).

Pre-operative planning and considerations

Physical examination and patient history are crucial in ruling out pseudo-gynecomastia and other causes than primary gynecomastia (see causes in pathophysiology). The prevalence of asymptomatic gynecomastia is 70% in men aged 50-69 years, whereas symptomatic gynecomastia is marked lower. Pre-operative examination includes: 

Patient history

  • Note the age of onset and duration
  • Ask about recent changes in nipple size, pain or discharge
  • Inquire if the patient has any history of testicular trauma or mumps
  • Ask about any alcohol- or drug use (both prescription- and over-the-counter medications together with recreational drugs)
  • Catch up if there is a history of GM in the family
  • Finally, evaluate if the patient has any sexual dysfunction, infertility or hypogonadism (2-6)

Patient presentation – physical examination

Most commonly, GM presents bilaterally, but unilateral may be seen as well. When palpating the affected breast(s), you feel an elastic, rounded and discoid process, located centrally beneath the NAC. The glandular tissue is tender and only in 2 percent, nipple discharge occurs (6). 

When assessing the level of GM, the Tanner Scale (grade 1-5)  is often used (6):

This image has an empty alt attribute; its file name is tanner_MarieHelles.jpg
Figure 2 | Level of gynecomastia.

Grade 1: No glandular tissue.

Grade 2: Forming breast buds. Small area of surrounding, glandular tissue. Widening of areola.

Grade 3: Breast more elevated, extending around the areola area, but remains following the skin contour.

Grade 4: Increased breast size and elevation. NAC elevated from the skin.

Grade 5: Final breast development. NAC again in contour of the breast with a central projection.

Additional physical examination:

  • Breast ptosis and residual skin
  • Breast gland or adipose tissue? Isolated masses and tenderness
  • Palpation of thyroid gland and testes
  • Palpation of lymph nodes (breast cancer?)


Illustrators: Christian Paaskesen, med.stud.


  1. Thorne, Charles Hm et al, Grabb and Smith’s Plastic Surgery (Wolters Kluwer, 7th ed, 2013;2014;)
  2. Sansone A, Romanelli F, Sansone M, Lenzi A, Di Luigi L. Gynecomastia and hormones. Endocrine. 2017 Jan 1;55(1):37–44.
  3. Swerdloff RS, Ng CM. Gynecomastia: Etiology, Diagnosis, and Treatment. In: Feingold KR, Anawalt B, Boyce A, Chrousos G, de Herder WW, Dungan K, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000 [cited 2020 Oct 22]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK279105/
  4. Kjems E, Tranberg Kejs AM. Statistik om brystkræft hos mænd. 2019;
  5. Blau M, Hazani R, Hekmat D. Anatomy of the Gynecomastia Tissue and Its Clinical Significance. Plast Reconstr Surg Glob Open [Internet]. 2016 Aug 30 [cited 2020 Jun 9];4(8). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5010345/
  6. Johnson RE, Murad MH. Gynecomastia: Pathophysiology, Evaluation, and Management. Mayo Clin Proc. 2009 Nov;84(11):1010–5.

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