Should You Order Ultrasound for Gynecomastia?
No, you should not routinely order ultrasound for typical bilateral painless gynecomastia in an adolescent or young adult male—most cases can be diagnosed clinically without any imaging. 1, 2, 3
When Imaging Is NOT Needed
- For clinical findings consistent with typical gynecomastia (soft, rubbery, or firm mobile subareolar mass), no imaging is recommended. 1, 2
- The American College of Radiology explicitly warns that unnecessary imaging in clear cases of gynecomastia leads to additional unnecessary benign biopsies without improving outcomes. 1, 2
- Breast ultrasound is not routinely recommended for gynecomastia evaluation. 4
When Imaging IS Indicated
Order imaging only when you cannot clinically differentiate benign disease from breast cancer, or when presentation features are suspicious. 1, 2
Red flags requiring imaging include:
- Unilateral mass (gynecomastia is bilateral in ~50% of cases, so unilateral presentation warrants suspicion) 1, 3
- Hard, fixed, or eccentric mass (rather than soft, mobile, subareolar) 1
- Bloody nipple discharge 1
- Skin or nipple retraction 1
- Indeterminate mass on physical examination 1, 2
Age-Based Imaging Algorithm (When Imaging Is Needed)
For males younger than 25 years:
- Start with ultrasound as the initial imaging modality due to extremely low breast cancer incidence in this age group. 1, 2, 3
- If ultrasound shows suspicious or indeterminate features, proceed to mammography or digital breast tomosynthesis before considering biopsy—gynecomastia and benign lesions can appear suspicious on ultrasound but are typically diagnosed as benign on mammography. 1, 2
For males 25 years and older:
- Start with mammography or digital breast tomosynthesis (sensitivity 92-100%, specificity 90-96%, negative predictive value 99-100%). 1, 2
- Follow with ultrasound if mammogram is indeterminate or suspicious. 1
Clinical Pearls
- Differentiate true gynecomastia from pseudogynecomastia (fatty tissue rather than glandular enlargement), especially in patients with elevated BMI—this distinction can be made clinically by palpating for glandular tissue directly under the nipple. 1, 3
- Gynecomastia is often painful when present for less than 6 months. 1
- Male breast cancer is rare (<1% of all breast cancers, median age 63 years), but should be ruled out in older men with suspicious features. 1, 2, 3
Common Pitfall to Avoid
Do not reflexively order imaging for every case of gynecomastia. The American College of Radiology emphasizes that most men with breast symptoms can be diagnosed based on clinical findings alone, and unnecessary imaging drives additional unnecessary biopsies. 1, 2, 3 Reserve imaging for cases where malignancy cannot be clinically excluded or when specific suspicious features are present.