What is the appropriate workup for gynecomastia?

Gynecomastia Workup

Begin with a focused physical examination to differentiate true gynecomastia from pseudogynecomastia, then proceed with targeted laboratory testing based on clinical findings—most cases do not require imaging unless malignancy is suspected. 1

Physical Examination

Palpate for glandular tissue directly beneath the nipple to distinguish true gynecomastia (soft, rubbery, or firm mobile mass) from pseudogynecomastia (fatty tissue deposition without discrete glandular tissue), particularly in patients with elevated BMI. 1

• Assess bilaterality: Approximately 50% of gynecomastia cases are bilateral; unilateral presentation warrants higher suspicion for malignancy. 1
• Evaluate pain: Gynecomastia present for less than 6 months is often painful, while longstanding cases are typically painless. 1
• Examine for suspicious features: Hard, fixed, eccentric masses, bloody nipple discharge, or skin/nipple retraction require immediate imaging to exclude breast cancer. 1

Perform a complete testicular examination to assess testicular size, consistency, and presence of masses or varicocele, as testicular tumors can present with gynecomastia. 1, 2

Evaluate virilization status by examining body hair patterns in androgen-dependent areas (face, chest, pubic region) to screen for hypogonadism. 1

Calculate BMI or measure waist circumference to assess for obesity-related hormonal changes. 1

Check for visual field defects (bitemporal hemianopsia) to identify pituitary disorders. 1

Laboratory Testing

Order morning total testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) as the initial hormonal panel to characterize the hormonal profile and distinguish primary from secondary hypogonadism. 3, 1

Measure serum estradiol in all patients before considering any hormonal therapy, particularly in testosterone-deficient patients. 3, 1

Add prolactin measurement if testosterone is low with low or normal LH to exclude hyperprolactinemia as a contributing factor. 3, 1

If free testosterone assessment is needed (when total testosterone is borderline), use equilibrium dialysis or calculate it using total testosterone, SHBG, and albumin. 1

In patients with testicular abnormalities on examination, obtain serum tumor markers (alpha-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase) before any surgical intervention. 2

Imaging Algorithm

No imaging is routinely recommended for patients with clinical findings clearly consistent with gynecomastia or pseudogynecomastia, as unnecessary imaging leads to additional benign biopsies without improving outcomes. 1

Proceed with imaging only if:

• Differentiation between benign disease and breast cancer cannot be made clinically 1
• Presentation is suspicious (unilateral, hard, fixed, eccentric mass) 1
• Bloody nipple discharge or skin/nipple retraction is present 1

Age-Based Imaging Selection

For men younger than 25 years: Ultrasound is the initial imaging study of choice. 1, 2

For men 25 years and older: Mammography or digital breast tomosynthesis is the initial imaging study, with sensitivity of 92-100%, specificity of 90-96%, and negative predictive value of 99-100%. 1

For suspected testicular tumors causing gynecomastia: High-frequency (>10 MHz) testicular ultrasound is the first-line imaging modality. 2

Endocrinology Referral Criteria

Refer all patients with elevated baseline estradiol measurements to an endocrinologist for comprehensive hormonal evaluation to determine the underlying cause. 1

The endocrinologist will assess for testosterone deficiency, abnormal LH levels, and hyperprolactinemia, and may consider selective estrogen receptor modulator therapy in appropriate candidates. 1

Substance Use Assessment

Inquire specifically about alcohol and cannabis use, as both can cause gynecomastia through distinct pathophysiologic mechanisms:

• Alcohol impairs hepatic clearance of steroid precursors and directly suppresses testicular testosterone production. 3
• Cannabis, particularly when initiated during adolescence, may affect hormonal systems. 3

Substance cessation is the primary intervention for drug-induced gynecomastia. 3

Medication Review

Review all medications for known gynecomastia-inducing agents:

• GnRH agonists (leuprolide, goserelin) suppress testosterone production 1
• Anti-androgens used in prostate cancer treatment 1
• Exogenous estrogens and estrogen-like compounds (diethylstilbestrol, digoxin, phytoestrogens) 1

Common Pitfalls

Do not order breast ultrasound routinely in clear cases of gynecomastia, as this leads to unnecessary biopsies. 1

Do not assume all breast enlargement is benign: Male breast cancer accounts for <1% of all breast cancers but has a median age of 63 years at diagnosis. 1

Do not overlook diabetes: Men with diabetes have lower testosterone concentrations than age-matched non-diabetic men, and optimizing glycemic control may improve hormonal profiles. 1

Recognize high-risk populations: Klinefelter syndrome patients have a 24.7-fold increased risk of gynecomastia, and BRCA2 mutation carriers have elevated risk of male breast cancer. 2

Idiopathic gynecomastia predicts future disease risk: Males with idiopathic gynecomastia have significantly higher risk of future endocrine, musculoskeletal, and circulatory diseases, warranting ongoing surveillance. 4