What is the diagnosis and treatment for gynecomastia (enlargement of breast tissue in males)?

From the Guidelines

Gynecomastia can often be diagnosed and managed without imaging, as most cases are benign and can be identified through clinical findings, with treatment depending on severity, cause, and patient distress. The diagnosis of gynecomastia is typically made based on physical examination, where it presents as a soft, rubbery, or firm mobile mass directly under the nipple, and is more likely to be painful than cancer, especially if present for less than 6 months 1.

Key Considerations

• Gynecomastia is the most common cause of a palpable mass, breast enlargement, or pain in men, and is bilateral in approximately half of patients 1.
• For mild cases, reassurance may be sufficient as many resolve spontaneously within 1-2 years.
• For persistent or bothersome gynecomastia, medications like tamoxifen or raloxifene can be effective by blocking estrogen receptors in breast tissue.
• If medication fails or for long-standing cases, surgical options include liposuction, excision of glandular tissue, or both.
• Addressing underlying causes is essential, including discontinuing contributing medications, treating hormonal disorders, reducing alcohol intake, and avoiding anabolic steroids.
• Weight loss may help in overweight individuals as adipose tissue converts testosterone to estrogen.

Imaging Recommendations

• If the differentiation between benign disease and breast cancer cannot be made on the basis of clinical findings, or if the clinical presentation is suspicious, imaging is indicated 1.
• In men with clinical findings consistent with gynecomastia or pseudogynecomastia, no imaging is routinely recommended.
• If an indeterminate breast mass is identified, the initial recommended imaging study is ultrasound in men younger than age 25, and mammography or digital breast tomosynthesis in men age 25 and older.

From the Research

Definition and Prevalence of Gynecomastia

• Gynecomastia is a benign proliferation of the glandular tissue of the breast in men, with a reported prevalence of 32-65% depending on age and criteria used for definition 2.
• The condition is common in infancy and puberty, with most cases resolving spontaneously, but it can also occur in adulthood, where proper investigation may reveal an underlying pathology in 45-50% of cases 2.
• Gynecomastia can be caused by both physiologic and nonphysiologic factors, including hypogonadism, altered estrogen-to-androgen ratio, and the use of certain drugs or herbal products 3.

Diagnosis and Evaluation of Gynecomastia

• The purpose of gynecomastia assessment is to detect underlying pathological conditions, reversible causes, and to discriminate from other breast lumps, particularly breast cancer 2.
• Evaluation should comprise a thorough medical history and physical examination of the breast and genitalia, including testicular ultrasound 2.
• Laboratory investigations may include testosterone, estradiol, sex hormone-binding globulin, luteinizing hormone, follicular stimulating hormone, thyroid stimulating hormone, prolactin, human chorionic gonadotropin, alpha-fetal protein, and liver and renal function tests 2.
• Breast imaging may be used when the clinical examination is equivocal, and core needle biopsy should be performed if the clinical picture is suspicious for a malignant lesion 2.

Treatment and Management of Gynecomastia

• Watchful waiting is recommended after treatment of underlying pathology or discontinuation of substances associated with gynecomastia 2.
• Testosterone treatment should be offered to men with proven testosterone deficiency 2.
• The use of selective estrogen receptor modulators, aromatase inhibitors, and non-aromatizable androgens is not justified in general, except in specific cases where pharmacological treatment may be beneficial, such as in pubertal gynecomastia 4.
• Surgical treatment is the therapy of choice for patients with long-lasting gynecomastia that does not regress spontaneously or following medical therapy 2.

Pharmacological Treatments for Gynecomastia

• Tamoxifen and other selective estrogen receptor modulators have been used as treatments for gynecomastia, particularly in pubertal cases, and have been found to be effective and safe with minimal side effects 4.
• Aromatase inhibitors, such as anastrozole and letrozole, may also be used in the treatment of gynecomastia, although more research is needed to determine their efficacy and safety 5.
• Pharmacological treatment may have an advantage in relieving behavioral and psychological distress associated with gynecomastia, particularly in adolescents 4.