From the Guidelines
Androgen resistance, also known as androgen insensitivity syndrome (AIS), can lead to gynecomastia due to an imbalance between estrogen and androgen effects in the body, and the most appropriate initial approach is to evaluate the patient's symptoms and physical examination findings, with imaging only recommended if the clinical presentation is suspicious or if an indeterminate breast mass is identified 1. When evaluating a patient with symptoms of gynecomastia, it is essential to consider the physical examination findings, as gynecomastia often 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. The treatment of gynecomastia due to androgen resistance typically involves addressing the underlying hormonal imbalance, and may include medications such as:
- Selective estrogen receptor modulators (SERMs) like tamoxifen (10-20 mg daily) or raloxifene (60 mg daily) for 3-9 months
- Aromatase inhibitors like anastrozole (1 mg daily) to reduce the conversion of androgens to estrogens For persistent gynecomastia that doesn't respond to medical therapy, surgical options including liposuction or mastectomy may be necessary 1. It is also important to note that gynecomastia is not believed to be a risk factor for male breast cancer, although approximately 50% of men with breast cancer may have coexisting gynecomastia 1. Regular follow-up is important to monitor treatment effectiveness and potential side effects of hormonal medications, and to evaluate for other manifestations of androgen insensitivity, which can vary from mild to complete forms 1.
From the Research
Androgen Resistance and Gynecomastia
- Androgen resistance is one of the causes of gynecomastia, which is defined as a unilateral or bilateral persistent benign mammary gland enlargement in men 2.
- Gynecomastia is triggered by an imbalance of female to male hormones, which can be caused by endogenous diseases like hyperthyroidism, chronic liver disease, primary or secondary gonadal failure, androgen resistance syndromes, medication, and drug abuse 2.
- The prevalence of gynecomastia is up to 65%, and it is a frequent condition with a reported prevalence of 32-65%, depending on the age and the criteria used for definition 2, 3.
- The aim of gynecomastia assessment should be the detection of underlying pathological conditions, reversible causes, and the discrimination from other breast lumps, particularly breast cancer 3.
- Assessment should comprise a thorough medical history and physical examination of the breast and genitalia, including testicular ultrasound 3.
- 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, liver, and renal function tests 3.
- Treatment options for gynecomastia include watchful waiting, medical therapy with tamoxifen, and surgical treatment 2, 3, 4.
- Surgical treatment is the therapy of choice for patients with long-lasting gynecomastia, which does not regress spontaneously or following medical therapy 3, 4.
- Androgen deprivation therapy, which is used in the treatment of prostate cancer, can also cause gynecomastia, and treatment options include radiotherapy, tamoxifen, and surgery 4.
Causes of Gynecomastia
- Androgen resistance syndromes 2
- Hyperthyroidism 2
- Chronic liver disease 2
- Primary or secondary gonadal failure 2
- Medication and drug abuse 2
- Androgen deprivation therapy 4