Gynecomastia Workup
Most men with gynecomastia can be diagnosed based on clinical findings alone without imaging or laboratory testing, unless there are suspicious features for malignancy or underlying endocrine disorders. 1
Initial Clinical Assessment
Physical Examination - Key Features to Identify
Confirm true gynecomastia by palpating for a soft, rubbery, or firm mobile mass directly under the nipple (often painful if present <6 months), distinguishing this from pseudogynecomastia which is fatty tissue deposition without glandular enlargement, particularly in patients with elevated BMI 1, 2
Assess for suspicious features that warrant immediate imaging: unilateral mass that is hard, fixed, or eccentric to the nipple; bloody nipple discharge; or retracted skin/nipple 1
Perform testicular examination to assess size, consistency, presence of masses, and evaluate for varicocele, as testicular pathology can cause hormonal imbalances 1
Evaluate virilization status by examining body hair patterns in androgen-dependent areas to assess for hypogonadism 1
Calculate BMI or measure waist circumference to assess for signs of underlying systemic conditions 1
Assess prostate size and morphology to look for abnormalities indicating prostate pathology 1
Examine for visual field changes (bitemporal hemianopsia) suggesting pituitary disorders 1
Medication Review - Critical Step
- Obtain detailed medication history as numerous drugs cause gynecomastia, including: 3
- Spironolactone (switch to eplerenone if gynecomastia develops) 3
- Antiandrogens (bicalutamide, flutamide, cyproterone acetate) 3
- 5-alpha reductase inhibitors (finasteride, dutasteride) 3
- GnRH agonists/antagonists 3
- Ketoconazole 3
- Testosterone or anabolic steroids (convert to estrogens) 3
- Hyperprolactinemia-inducing drugs 3
- Chronic cannabis use 3
Imaging Decision Algorithm
When NO Imaging is Needed
Clinical findings consistent with bilateral or unilateral gynecomastia without suspicious features - no routine imaging recommended 1, 2
Pseudogynecomastia in obese patients - no imaging needed 1
When Imaging IS Indicated
For men <25 years with indeterminate or suspicious findings: Start with ultrasound 1, 2
For men ≥25 years with indeterminate or suspicious findings: Start with mammography or digital breast tomosynthesis (sensitivity 92-100%, specificity 90-96%, NPV 99-100%) 1, 2
Laboratory Testing - When to Order
Indications for Hormonal Workup
Refer to endocrinology if elevated baseline estradiol is suspected or if no clear medication/physiologic cause is identified 1
Measure serum estradiol in testosterone-deficient patients who present with breast symptoms or gynecomastia prior to starting testosterone therapy 1
Expected endocrine testing includes: 1
- Serum testosterone levels
- Serum estradiol levels
- Luteinizing hormone (LH) levels
- Prolactin levels (if testosterone is low with low/normal LH)
Common Pitfalls to Avoid
Unnecessary imaging in clear cases of gynecomastia leads to additional unnecessary benign biopsies 1
Missing breast cancer - though rare (<1% of all breast cancers, median age 63 years), it must be ruled out in suspicious presentations, particularly in older men, those with BRCA2 mutations, or Klinefelter syndrome 1, 2
Failing to recognize bilateral presentation - gynecomastia is bilateral in approximately 50% of patients 1, 2
Not considering physiologic causes - gynecomastia often resolves spontaneously in up to 50% of patients with observation alone 1
Special Considerations
Men interested in fertility should have reproductive health evaluation performed prior to treatment 1
Patients on testosterone therapy who develop gynecomastia should undergo monitoring as symptoms sometimes abate without intervention 1
Patients starting antiandrogen therapy for prostate cancer should receive prophylactic breast irradiation (8-15 Gy in 1-3 fractions) 1-2 weeks before initiation to prevent painful gynecomastia 1