Gynaecomastia – Male breasts ultrasound

Gynaecomastia

 

What is gynecomastia?

Gynecomastia is overdevelopment of the male breast. In response to too much estrogen (a female hormone) or too little testosterone (a male hormone), the glandular tissue of the breast swells and forms a breast bud (enlarged breast). Gynecomastia can occur in babies, teen boys, and older men.

What causes gynecomastia?

In newborns, gynecomastia is caused by estrogen from the mother. Breast buds are common in baby boys. Breast buds tend to go away gradually by 6 months of age, but they can last longer in some babies.

In preteen boys, gynecomastia can also be caused by an estrogen-producing tumor. Breast buds are common during puberty. The buds may last up to 2 years, but they tend to go away within the first year.

In teen boys, gynecomastia is caused by the hormonal changes ofpuberty. Gynecomastia occurs in many boys during early puberty to middle puberty. It usually goes away within 6 months to 2 years.

In adult males, gynecomastia is usually caused by another condition, such as liver or lung cancer, cirrhosis of the liver, overactive thyroid, or by hormone problems, such as cancer of the pituitary gland, adrenal glands, or testicles. Alcohol, marijuana, methamphetamine, andheroinuse also may cause gynecomastia.

Use of certain medicines may also cause gynecomastia, including:

• Steroids, such as prednisone or dexamethasone.
• Medicines used to treat ulcers (such ascimetidine).
• Medicines used to treat epilepsy (such as phenytoin [Dilantin]).
• Digitalis and other heart medicines.
• Chemotherapy drugs, especially alkylating agents, a family of anticancer drugs that interfere with cell DNA and inhibit cancercell growth.
• Antiandrogen drugs (such as flutamide, cyproterone, andspironolactone).
• Antianxiety and antidepressant medicines (such asdiazepam[Valium] and tricyclic antidepressants).

What are the symptoms?

In addition to having enlarged breasts, men or boys with gynecomastia may notice their breasts feel rubbery or firm. Boys may have a breast bud on one or both sides about the size of a nickel or quarter. Breast buds are common in adolescent boys during puberty. They may last up to 2 years, but they tend to go away within the first year.

Epidemiology

While it can occur at any age, it tends to have greater prevalence in two groups : adolescent boys and older men (some publications describe a trimodal age distribution, occurring in neonatal, pubertal, and elderly males 8)

Pathology

In gynaecomastia, there is enlargement of the male breast due to benign ductal and stromal proliferation. A hallmark of gynaecomastia is its central symmetric location under the nipple. Gynaecomastia in most cases tends to be unilateral and / or asymmetrical 3.

The imbalance between estrogen action relative to androgen action at the breast tissue level appears to be a key etiological factor in gynaecomastia 8.

Causes

The causes of gynaecomastia are many and include:

• hormonal:
  • neonatal: maternal estrogens
  • pubertal: high estradiol levels
  • elderly: decline in testosterone levels
  • hypogonadism/androgen deficiency states:
    • Klinefelter’s syndrome
    • anarchism
    • testicular failure, e.g. testicular cancer
  • drugs:
    • diethylstilbestrol
    • spironolactone
    • thiazide diuretics
    • digoxin
    • anabolic steroids
    • estrogen treatment
    • isoniazid
    • ergotamine
    • narcotics:
      • marijuana
      • heroin
    • cimetidine
    • nifedipine
    • reserpine
    • methyldopa
    • theophylline
  • systemic disorders:
    • advanced alcoholic cirrhosis
    • haemodialysis in chronic renal failure
    • chronic pulmonary disease, e.g. emphysema, tuberculosis
    • malnutrition
  • tumors: particularly estrogenic tumors
    • adrenal carcinoma
    • pituitary adenoma

testicular tumors

• hyperthyroidism
• hepatoma

• idiopathic

There can be three forms of gynaecomastia Histologically:

• florid
• intermediate
• fibrotic

Gynaecomastia can be asymmetrical and at times even be unilateral.

Radiographic features

Mammography

May appear as an increased sub-areolar density, which may be flame-shaped.

Three mammographic patterns of gynaecomastia have been described representing various degrees and stages of ductal and stromal proliferation. They are:

• nodular pattern
• dendritic pattern
• diffuse glandular pattern

Early nodular gynaecomastia (florid phase) is seen in patients with gynaecomastia for less than 1 year. At mammography, there is often a nodular subareolar density.

Chronic dendritic gynaecomastia (quiescent phase) is seen in patients with gynaecomastia for longer than 1 year. Fibrosis becomes the dominant process and is irreversible. Mammograms this phase typically show a dendritic subareolar density with posterior linear projections radiating into the surrounding tissue toward the upper-outer quadrant.

Diffuse glandular gynaecomastia is commonly seen in patients receiving exogenous estrogen. At mammography, there is enlargement of the breast and diffuse density with both dendritic and nodular features.

Breast ultrasound

Focal gynaecomastia can variably appear as a retroareolar, triangular, hypoechoic ( ~ 80% 2) mass.

In early nodular gynaecomastia there can be subareolar fan or disc shaped hypoechoic nodule surrounded by normal fatty tissue.

In diffuse glandular gynaecomastia both nodular and dendritic features are seen surrounded by diffuse hyperechoic fibrous breast tissue.

In chronic dendritic gynaecomastia, there is a often a subareolar hypoechoic lesion with an anechoic star-shaped posterior border, which can be described as finger like projections or “spider legs” insinuating into the surrounding echogenic fibrous breast tissue.

SteveRmasey, PhD

Calgary, Alberta