Peak incidence: onset of puberty
Dilatation of spermatic cord veins (pampiniform plexus)
~90% occur on left due to 90 degree turn of left testicular vein into left renal vein
R testicular vein drains into IVC
If right-sided, consider inferior vena cava thrombosis
Can impair sperm production/function leading to infertility
Sudden appearance may be related to renal malignancy obstructing venous return
~90% occur on left due to 90 degree turn of left testicular vein into left renal vein
R testicular vein drains into IVC
If right-sided, consider inferior vena cava thrombosis
If right-sided, consider inferior vena cava thrombosis
Varicocele
Scrotal cellulitis
Hematocele
Epididymitis
Hydrocele
Fournier gangrene
Hydrocele 
Inguinal hernia 