Spermatocele

Overview 

A spermatocele, or spermatic cyst, is a benign fluid-filled cyst arising from the epididymis, usually near the upper pole of the testis. It commonly contains clear or milky fluid with spermatozoa. Most spermatoceles are painless, discovered incidentally and do not require treatment.

Pathophysiology

• Obstruction of an epididymal or efferent duct causes accumulation of sperm-containing fluid.
• The affected duct gradually dilates, forming a cyst.
• Spermatoceles commonly arise from the head of the epididymis, above or behind the testis. 

Clinical Manifestations

• Usually asymptomatic and painless.
• Smooth, soft or fluctuant scrotal lump.
• Located above or behind the testis.
• Usually separate from the testis.
• Larger lesions may cause:
  • Dull scrotal discomfort
  • Heaviness
  • Fullness or swelling
  • Discomfort during physical activity or intercourse
• The mass may transilluminate

Diagnosis 

• Transillumination: supports a fluid-filled lesion but does not provide a definitive diagnosis.
• Scrotal ultrasound: performed when the diagnosis is uncertain or to exclude:
• Ultrasound usually demonstrates a well-defined cystic lesion arising from the epididymis.
• Any new or unexplained scrotal mass should be medically assessed to exclude testicular malignancy

Differential Diagnosis

• Testicular tumour
• Hydrocele
• Varicocele
• Epididymitis
• Inguinal hernia

Treatment

Asymptomatic spermatocele

• Reassurance and observation.
• No treatment or routine intervention is required.
• Review if the mass enlarges, becomes painful or changes clinically.

Symptomatic spermatocele

• Simple analgesia, such as paracetamol.
• NSAIDs may be used if appropriate.
• Supportive underwear may reduce discomfort.
• Surgical treatment:
  • Spermatocelectomy may be considered for:
    • Persistent pain
    • Significant discomfort or heaviness
    • Large or progressively enlarging lesion
    • Interference with daily activities
  • The cyst is surgically separated from the epididymis, usually as a day procedure.
  • Fertility implications should be discussed before surgery, particularly in younger patients.
• Aspiration and sclerotherapy
  • Rarely used because fluid may reaccumulate.
  • Sclerotherapy involves aspiration followed by injection of an agent that scars the cyst lining.
  • May damage the epididymis and potentially affect fertility.

Complications and Prognosis

Complications 

• Most spermatoceles cause no complications.
• Large lesions may cause persistent pain, heaviness or cosmetic concern.
• A spermatocele itself usually does not impair fertility.

Prognosis

• Prognosis is excellent.
• Spermatoceles are benign and do not become cancerous.
• Many remain stable and asymptomatic for years.
• Treatment is generally effective when symptoms justify intervention, although recurrence can occur.
• Patients should seek prompt reassessment for sudden severe pain, rapid enlargement or a new hard intratesticular mass, as these findings may indicate another condition. 

References

1. Mayo Clinic. Spermatocele: symptoms and causes [Internet]. Rochester: Mayo Foundation for Medical Education and Research; 2022.
2. Mayo Clinic. Spermatocele: diagnosis and treatment [Internet]. Rochester: Mayo Foundation for Medical Education and Research; 2022.
3. Merck Manual Professional Edition. Some causes of a painless scrotal mass [Internet]. Rahway: Merck & Co.; 2026.
4. Lundström KJ, Söderström L, Jernow H, Stattin P, Nordin P. Epidemiology of hydrocele and spermatocele: incidence, treatment and complications. Scand J Urol. 2019;53(2-3):134–138.