What is the definition of gynecomastia?

Definition of Gynecomastia

Gynecomastia is defined as a benign proliferation of male breast glandular tissue, either unilateral or bilateral, resulting from an imbalance between estrogen and androgen action at the breast tissue level. 1, 2

Clinical Presentation and Characteristics

Gynecomastia typically presents with the following features:

• A disc-like area of breast tissue under the nipple
• Bilateral in approximately 50% of cases
• Often tender, particularly in early stages
• Typically soft, rubbery, or firm and mobile 2

True Gynecomastia vs. Pseudogynecomastia

It's important to distinguish between:

• True gynecomastia: Actual glandular breast tissue enlargement
• Pseudogynecomastia: Fatty tissue deposition without glandular proliferation, common in patients with elevated BMI 2

Epidemiology and Natural History

• Affects at least one-third of males at some point during their lifetime 3
• Common during three specific life phases:
  1. Neonatal period
  2. Puberty
  3. Senescence (old age) 4
• Pubertal gynecomastia is self-limited in 75-90% of cases, typically regressing over 1-3 years 5
• Persists indefinitely in approximately 10% of cases 6

Etiology

The underlying pathophysiology involves an imbalance between estrogen and androgen action at the breast tissue level. Common causes include:

1. Physiologic causes:

   • Pubertal gynecomastia (21% of cases) 1
   • Senile gynecomastia (8.1% of cases) 1

2. Pathologic causes:

   • Hypogonadism (32.6% of cases) 1
   • Medication-induced (e.g., spironolactone, 5-α reductase inhibitors) 2, 7
   • Liver disease/cirrhosis 2
   • Idiopathic causes 3

Medication-Induced Gynecomastia

Several medications can cause gynecomastia:

• Spironolactone: Risk increases in a dose-dependent manner, with onset varying from 1-2 months to over a year 7
• 5-α reductase inhibitors (finasteride, dutasteride) 2

Diagnosis

Most cases of gynecomastia can be diagnosed based on clinical findings without imaging 2:

1. Clinical assessment:

   • Physical examination to differentiate true gynecomastia from pseudogynecomastia
   • Staging: Stage I (mild), Stage II (moderate), Stage III (severe) 1

2. Imaging:

   • Not indicated for typical presentations
   • Ultrasound or mammography should only be used for cases with indeterminate physical findings 2

3. Laboratory evaluation:

   • First-line assessment includes renal function, liver function, and thyroid function tests 1
   • Additional testing based on clinical suspicion

Psychological Impact

Gynecomastia can have significant psychological consequences:

• Anxiety and psychosocial discomfort 2
• Depression
• Body dissatisfaction
• Reduced self-esteem
• Disordered eating in some cases 6

Common Pitfalls in Diagnosis and Management

• Failure to recognize medication as the cause can lead to delayed intervention 2
• Unnecessary imaging may lead to additional procedures without clinical benefit 2
• Overlooking male breast cancer, which is rare (<1% of all breast cancers) but should be considered, especially in older men 2
• Neglecting psychological impact of gynecomastia, which can cause significant distress 6

By understanding the definition and characteristics of gynecomastia, clinicians can provide appropriate evaluation and management to address both the physical and psychological aspects of this condition.