Gynecomastia

Introduction

• Benign breast enlargement in males secondary to increased effective estrogen
  • can be increased production or decreased degradation
  • also result of decrease in androgens leaving estrogens unopposed
• May occur naturally throughout male life
  • newborn
    • secondary to high maternal estrogen
  • puberty 
  • elderly
    • secondary to androgen decrease
• Associated conditions
  • cirrhosis
  • genetic diseases
    • Klinefelter syndrome
      • increased aromatizing activity of Leydig cells
      • high estrogen results in increased male breast cancer risk
    • testicular feminization
  • cancer
    • choriocarcinoma of testis
      • high production of hCG (an LH analogue)
  • drugs
    • estrogen
    • marijuana
    • flutamide
      • blocks androgen receptors
    • leuprolide
      • blocks androgen production
    • psychoactive drugs
    • “Some Drugs Create Awesome Knockers”
      • Spironolactone
        • block androgen receptors, displaces estrogen from SHBG
      • Digitalis
        • intrinsic estrogen activity
      • Cimetidine
      • Alcohol
      • Ketoconazole
        • displaces estrogen from SHBG