What is the initial workup for a patient presenting with gynecomastia?

Gynecomastia Workup

The initial workup for gynecomastia should include a thorough medical history, physical examination of breast and genitalia (including testicular ultrasound), and laboratory tests including testosterone, estradiol, SHBG, LH, FSH, TSH, prolactin, hCG, AFP, and liver and renal function tests. 1

Initial Assessment

Medical History

• Onset and duration of gynecomastia
• Medication use (particularly antipsychotics, phenytoin, 5-α reductase inhibitors, spironolactone) 2
• Substance use/abuse (anabolic steroids, marijuana, alcohol)
• Sexual development and function
• Symptoms of underlying conditions (liver disease, hypogonadism, thyroid disorders)

Physical Examination

1. Breast examination:

   • Confirm presence of palpable glandular tissue (vs. pseudogynecomastia/lipomastia)
   • Assess for suspicious features of malignancy:
     • Hard or firm mass
     • Rapid growth
     • Skin changes
     • Nipple discharge or retraction
     • Axillary lymphadenopathy

2. Genital examination:

   • Assess testicular size (atrophy suggests hypogonadism)
   • Palpate for testicular masses 1
   • Look for signs of under-virilization

3. General physical examination:

   • Signs of systemic disease (liver disease, thyroid disorders)
   • Secondary sex characteristics

Diagnostic Testing

First-line Laboratory Tests

• Testosterone (total and free)
• Estradiol (E2)
• Sex hormone-binding globulin (SHBG)
• Luteinizing hormone (LH)
• Follicle-stimulating hormone (FSH)
• Thyroid-stimulating hormone (TSH)
• Prolactin
• Human chorionic gonadotropin (hCG)
• Alpha-fetoprotein (AFP)
• Liver and renal function tests 1

Imaging

• Testicular ultrasound is recommended due to low sensitivity of physical examination for testicular tumors 1
• Breast imaging (ultrasound or mammography) only if:
  • Clinical examination is equivocal
  • Suspicious features for malignancy
  • Asymmetric or rapidly growing breast tissue 1, 3

Additional Testing

• Core needle biopsy if suspicious for malignancy 1

Common Pitfalls and Caveats

1. Failure to distinguish true gynecomastia from pseudogynecomastia:

   • True gynecomastia: glandular breast tissue enlargement
   • Pseudogynecomastia: fatty tissue deposition without glandular proliferation 2

2. Overlooking medication causes:

   • Even when medications are identified as potential causes, a thorough workup is still recommended in adults 1
   • Common culprits include antipsychotics, spironolactone, finasteride, and phenytoin 2

3. Missing testicular tumors:

   • Physical examination alone has low sensitivity
   • Testicular ultrasound should be included in the workup 1

4. Unnecessary imaging:

   • Breast ultrasound is not routinely recommended unless physical examination is concerning 3

5. Delayed management:

   • Gynecomastia present for >12 months may develop fibrosis and be more difficult to treat 3

Special Considerations

Age-specific Approach

• Neonatal gynecomastia: Usually self-limited, resolves within first year 1
• Pubertal gynecomastia: Affects ~50% of mid-pubertal boys, resolves spontaneously in >90% within 24 months 1
• Adult gynecomastia: Higher likelihood of underlying pathology (45-50% of cases) 1

Malignancy Risk

• Male breast cancer is rare (<1% of all breast cancers)
• Gynecomastia is not considered a premalignant condition 1, 3
• Median age for male breast cancer is 63 years 2

By following this structured approach to the workup of gynecomastia, clinicians can effectively identify underlying causes and determine appropriate management strategies for patients.