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Gynecomastia: Differential Diagnosis of Male Breast Enlargement

Gynecomastia is defined as a benign glandular enlargement of the male breast. Gynecomastia must be distinguished from breast enlargement due to tumor or fat deposition.

Differential Diagnosis of Gynecomastia

Physiological Gynecomastia

• Newborn gynecomastia
• Gynecomastia in adolescents

Increase in Estrogens or Androgens Causes Gynecomastia

• Puberty
• Obesity
• Testicular tumors (Leydig-cell tumor, choriocarcinoma)
• Liver cirrhosis
• Hyperthyroidism
• Abuse of anabolic steroids

Hypergonadotropic Hypogonadism may cause Gynecomastia

• Klinefelter syndrome
• Anti-androgenic therapy
• Reifenstein syndrome
• Testicular feminization
• Bilateral testicular disease or loss of testes (e.g., mumps orchitis)

Hyperprolactinemia causes Gynecomastia

• Pituitary adenomas
• Drugs (see below)

Drugs causing Gynecomastia

• Antiandrogens: bicalutamide, flutamide, cyproterone acetate
• Possible side effects of testosterone therapy
• Spironolactone
• Metoclopramide
• Cimetidine
• Digitalis
• Psychotropic drugs, cannabis

Idiopathic Gynecomastia

The cause of gynecomastia cannot be identified in 50%. Gynecomastia is associated with the following chronic diseases: liver cirrhosis, diabetes mellitus, tuberculosis, heart failure and chronic kidney disease.

Non-glandular Male Breast Enlargement

• Obesity: combination of excessive caloric intake and lack of physical activity. Alcohol consumption increases the caloric intake.
• Tumors are rare and often one-sided: breast cancer, fibroadenoma, neurofibroma.

Diagnostic Workup of Gynecomastia

History and Physical Examination:

• History: Risk factors for gynecomastia? Medication?
• Body weight and height
• Size of the testes
• Asymmetric or bilateral gynecomastia? Palpation: tumor?

Labatory tests:

Testosterone in serum, LH, FSH, TSH, prolactin.

Imaging studies:

Ultrasound imaging and/or mammography, if a tumor is suspected.

  Deutsche Version: Differentialdiagnose der Gynäkomastie