What is the difference between a hydrocele and a varicocele?

Hydrocele versus Varicocele: Key Differences

A hydrocele is a fluid collection around the testis, while a varicocele is an abnormal dilation of the pampiniform venous plexus in the spermatic cord—they are fundamentally different conditions with distinct presentations, implications, and treatments.

Anatomic and Pathophysiologic Differences

Hydrocele:

• Accumulation of serous fluid between the layers of the tunica vaginalis surrounding the testis 1
• Generally asymptomatic and managed supportively 2
• Presents as a painless scrotal mass that transilluminates 2

Varicocele:

• Abnormal dilation and tortuosity of the pampiniform venous plexus within the spermatic cord 3
• Affects approximately 15% of normal males but 35-40% of men presenting with infertility 3
• Presents as a "bag of worms" feeling on palpation, typically more prominent on the left side 4
• Associated with higher scrotal temperature, testicular hypoxia, and reflux of toxic metabolites 5

Clinical Presentation Differences

Hydrocele characteristics:

• Painless, smooth scrotal swelling 2
• Transilluminates with light 2
• Does not change with position or Valsalva maneuver 1
• No impact on fertility 2

Varicocele characteristics:

• May present with chronic scrotal pain, infertility, or be asymptomatic 4
• Increases in size with standing or Valsalva maneuver 3
• Diagnosed by palpation of a prominent pampiniform plexus 3
• Higher grades (grade 3) associated with worse semen parameters and greater testicular dysfunction 5, 3

Diagnostic Approach

For both conditions:

• Ultrasound with color Doppler is the primary imaging modality 1
• Physical examination remains the cornerstone of diagnosis 3, 2

Varicocele-specific findings:

• Increase in spermatic cord diameter during Valsalva maneuver 3
• Mean maximal vein diameter: 5.0 mm (grade I), 5.8 mm (grade II), 6.6 mm (grade III) versus 2.5 mm in normal testicular units 3
• Routine ultrasonography to identify non-palpable varicoceles is discouraged 5, 3

Hydrocele-specific findings:

• Anechoic fluid collection on ultrasound 1
• Scrotal wall thickening may be present with reactive hydroceles 1

Treatment Implications

Hydrocele:

• Supportive management for asymptomatic cases 2
• Surgical intervention (hydrocelectomy) only for symptomatic or large hydroceles 2

Varicocele:

• Treatment indicated for infertile men with clinical varicocele and abnormal semen parameters 5, 3
• Microsurgical varicocelectomy is the preferred technique, with significantly lower complication rates 6
• Treatment in adolescents recommended when associated with persistent testicular size difference >2 mL or 20% 5, 3
• Subclinical (non-palpable) varicoceles should not be treated 5, 3

Critical Relationship Between the Two Conditions

Hydrocele can develop as a complication of varicocele repair:

• Conventional varicocelectomy techniques have substantial risk of hydrocele formation (9% in some series) 6
• Laparoscopic varicocelectomy has even higher rates of hydrocele formation (22.8-29.8%) 7
• Microsurgical technique with testicular delivery and lymphatic preservation eliminates hydrocele risk (0% in 382 patients) 6
• Percutaneous embolization avoids lymphatic channels entirely, with no hydrocele formation reported 8

Common Pitfalls to Avoid

• Do not confuse a reactive hydrocele (secondary to epididymitis or torsion) with a primary hydrocele—the former requires treatment of the underlying condition 1
• Do not treat subclinical varicoceles identified only on ultrasound, as this does not improve fertility outcomes 5, 3
• When performing varicocelectomy, preserve lymphatic channels to prevent postoperative hydrocele formation 6, 7
• Do not attribute all scrotal swelling to hydrocele without ruling out testicular cancer with ultrasound 2