In a 14-year-old boy with a painless, non‑discharging, non‑red left nipple mass present for 1–2 years, what is the most likely diagnosis and the appropriate initial work‑up and management?

Adolescent Gynecomastia: Diagnosis and Management

Direct Answer

This 14-year-old boy almost certainly has physiologic pubertal gynecomastia, which requires no imaging or laboratory workup—only reassurance and observation, as it spontaneously resolves in 75-90% of cases over 1-3 years. 1, 2, 3

Clinical Diagnosis

The diagnosis is made clinically without imaging in adolescents with typical features:

• Gynecomastia presents as a soft, rubbery, or firm mobile mass directly under the nipple—exactly matching this patient's presentation 1
• The 1-2 year duration, absence of discharge, and lack of inflammatory signs are classic for physiologic pubertal gynecomastia 2, 3
• Pubertal gynecomastia occurs physiologically in adolescents due to transient imbalances between estrogen and androgen during development 1, 2
• Most men with breast symptoms can be diagnosed based on clinical findings alone without imaging 1

When Imaging is NOT Indicated

For this patient, imaging is explicitly not recommended:

• In males with clinical findings consistent with gynecomastia, mammography is not routinely indicated 1
• In males with clinical findings consistent with gynecomastia, ultrasound is not routinely indicated 1
• The American College of Radiology states that imaging is only indicated if differentiation between benign disease and breast cancer cannot be made on clinical findings, or if the presentation is suspicious 1

Red Flags That Would Change Management

This patient has NONE of the concerning features that would warrant imaging or further workup:

• Breast cancer in males typically occurs in older men (median age 63 years), not adolescents—only 1% of male breast cancers occur in men under age 30 1
• Suspicious features include: skin or nipple retraction, bloody/serous nipple discharge, hard fixed mass, or rapid growth 1
• The absence of discharge is particularly reassuring, as pathologic discharge (unilateral, spontaneous, serous/bloody) carries 10-32% malignancy risk depending on age 4

Laboratory Workup

No routine laboratory testing is needed for this patient:

• Not all patients with gynecomastia require extensive laboratory analysis 5
• Laboratory workup (testosterone, estradiol, gonadotropins, prolactin, thyroid function) is reserved for cases with atypical features suggesting underlying pathology 5, 6
• A detailed medication/substance history is more important than labs: inquire about anabolic steroids, marijuana, herbal products, and medications that can cause gynecomastia 2, 6

Management Strategy

The standard of care is reassurance and observation:

• Pubertal gynecomastia is self-limited in 75-90% of adolescents and regresses over 1-3 years 3
• Reassurance remains the standard of care for physiologic gynecomastia 2
• Close follow-up with observation is regarded as the best approach for pubertal gynecomastia 7

Assess psychological impact:

• Gynecomastia may cause significant psychological stress, depression, and decreased participation in physical activities due to embarrassment 2, 3, 6
• Psychosocial counseling may be required in selected cases 6

When to Consider Intervention

Medical therapy is an option only if specific criteria are met:

• Pharmacological therapy (antiestrogens like raloxifene or tamoxifen) is reasonable if given early in the disease course and is more successful with small-to-moderate breast enlargement 3
• Consider medical therapy only for persistent painful gynecomastia causing substantial tenderness or embarrassment 3, 7
• These drugs are not universally approved for gynecomastia treatment, as risks and benefits have not been completely studied 3

Surgical intervention criteria:

• Surgery is recommended if: medical therapy fails, no regression after 1 year observation, condition worsens, significant psychosocial problems arise, or patient has completed puberty 5
• Surgical removal by plastic surgery is the treatment of choice for chronic, bothersome gynecomastia 7

Common Pitfalls to Avoid

• Do not order imaging for typical adolescent gynecomastia—this leads to unnecessary radiation exposure, cost, and potential false-positive findings requiring additional workup 1
• Do not confuse gynecomastia with pseudogynecomastia (excess fatty tissue without glandular proliferation)—differentiation is made by palpating for firm subareolar glandular tissue 1, 6
• Do not rush to medical or surgical treatment—the vast majority resolve spontaneously, and premature intervention exposes patients to unnecessary risks 2, 3, 7