What is a varicocele, and what are its cross sectional imaging features?
A varicocele is an abnormal enlargement of the pampiniform plexus of veins in the scrotum, and it is encountered in ≈15% to 20% of men. Primary varicoceles result from incompetence of the valves in the gonadal vein, leading to retrograde venous blood flow. These are most often encountered on the left side (85%) or bilaterally (15%). Secondary varicoceles occur secondary to extrinsic compression of the gonadal vein, portacaval venous shunting (from portal hypertension), or thrombosis of the gonadal vein, renal vein, or inferior vena cava. A secondary varicocele should be suspected when an isolated right-sided varicocele is encountered.
On cross-sectional imaging, dilated (>2 to 3 mm) serpentine veins are seen, usually located superior and lateral to the testicle. Rarely, intratesticular varicoceles may be encountered. On US, varicoceles are anechoic in appearance and demonstrate increased blood flow and flow reversal during the Valsalva maneuver on Doppler US. On CT and MRI, these demonstrate venous phase enhancement.