II. Causes: Physiologic in Newborn, Puberty, Older men
- Physiologic Mechanisms
- Physiologic syndromes (25% of cases)
- Gynecomastia in the newborn
- Benign Gynecomastia of Adolescence
- Familial Gynecomastia
- Common X-Linked recessive or dominant trait
- Limited Breast development during Puberty
- No further evaluation unless Hypogonadism present
- Gynecomastia of aging
- Common in men over age 65 years (40-72%)
- Decreased androgen to Estrogen ratio
III. Causes: Secondary (75% of cases)
- See Medication Causes of Gynecomastia (10-25% of cases)
- Idiopathic (25% of cases)
- Cirrhosis (8% of causes)
-
Hypogonadism
- Klinefelter's Syndrome
- Kallman Syndrome
- Congenital anorchia
- 5a-reductase deficiency
- Androgen insensitivity
- Hemochromatosis
- Testicular Trauma (e.g. Testicular Torsion)
- Orchitis
-
Chronic Renal Failure (1% of cases)
- Gynecomastia resolves with Renal Transplant (improves partially with Dialysis)
-
Hyperthyroidism (2% of cases)
- Gynecomastia resolves within 2 months of treatment
-
Obesity
- Causes both pseudogynecomastia and Gynecomastia
- Primary tumor
- Adrenal tumor
- Testicular Tumor (e.g. Leydig, Sertoli cell tumor)
- Prolactin-Secreting adenomas
- Ectopic Hormone production (hcg Secreting tumors)
- Miscellaneous causes
- Familial Gynecomastia
- Human Immunodeficiency Virus (HIV)
- Ulcerative Colitis
- Cystic Fibrosis
- Lead Toxicity
- Phthalate Toxicity
IV. History: Red flags suggestive of non-physiologic Gynecomastia
- Persistent Gynecomastia for >2 years
- Nipple Discharge
- Breast Skin Changes
- Rapid Breast enlargement
- Firm Breast Mass
- Testicular Mass
- Weight loss
V. Signs
- Firm Breast swelling that is concentric centered under nipple and areola
- Bilateral involvement is most common (typically left sided when unilateral)
VI. Labs
- All patients
- Thyroid Stimulating Hormone (TSH)
- Serum Creatinine
- Serum AST and ALT
- Hormonally active tumor suspected
- Serum Beta hCG
- Serum Dehydroepiandrosterone
- Urinary 17-ketosteroid
-
Hypogonadism
- Serum Testosterone (total and free)
- Serum Estradiol
- Follicle Stimulating Hormone (FSH)
- Luteinizing Hormone (LH)
- Other labs to consider
VII. Differential Diagnosis
- Pseudogynecomastia (fatty tissue predominance)
- Breast Cancer
- Lipoma
- Sebaceous Cyst
- Mastitis
- Dermoid Cyst
- Trauma-related swelling (fat necrosis or Hematoma)
VIII. Imaging
-
Testicular Ultrasound indications
- Palpable Testicular Mass
- Gynecomastia size >5 cm
- Persistent Gynecomastia without obvious cause
- Serum HCG increased
- Breast Ultrasound (and possibly FNA) indications
- Breast Mass suspected
-
MRI Brain
- Prolactinoma suspected (increased Serum Prolactin)
IX. Management
- Evaluate for underlying cause
- Physiologic cause is a diagnosis of exclusion
- Observation
- Indicated in most cases
- Routine follow-up on an every 6 month basis
- Medical management
- Indicated in symptomatic or distressing Gynecomastia
- Tamoxifen 10 mg daily for 3 months
- Raloxifene (Evista) 60 mg daily for 3-9 months
- Dihydrotestosterone
- Danazol
- Clomiphene (Clomid)
- Surgical management
- Indicated in prolonged, severe, refractory to medication cases
X. References
- Wilson (1998) Williams Endocrinology, Saunders, 885-92
- Braunstein (1993) N Engl J Med 328:490-5 [PubMed]
- Braunstein (2007) N Engl J Med 357(12): 1229-37 [PubMed]
- Dickson (2012) Am Fam Physician 85(7):716-22 [PubMed]
- Sher (1998) Clin Pediatr 37(6):367-71 [PubMed]