PassFinals
Renal & Urology

Epididymal Cyst

An epididymal cyst is a benign, usually painless extratesticular cyst; the key task is to confirm that the testis itself is normal and to escalate any uncertain or intratesticular mass.

In a nutshell

An epididymal cyst is a benign extratesticular cyst, usually a painless lump above or behind a separately palpable testis. Confirm the anatomy; use ultrasound if uncertain or the testis cannot be assessed. Observe if asymptomatic. Refer for excision only when symptoms are significant, explaining recurrence and possible fertility effects.

Classic presentation

A man notices a smooth, painless, transilluminating lump at the upper pole of the testis; the testis is normal and palpable separately.

Key points

  • The key distinction is extratesticular and separate from the testis versus intratesticular and inseparable.
  • Ultrasound is appropriate for uncertainty, an unexaminable testis, unexplained or persistent symptoms, or concern about a solid lesion.
  • A confidently diagnosed benign cyst usually needs reassurance rather than routine intervention.
  • Sudden severe pain is an acute-scrotum problem until torsion is excluded, regardless of a known cyst.
  • Symptomatic excision is specialist-led; discuss recurrence and potential epididymal/fertility effects.

First-line investigation

Focused scrotal examination; ultrasound if the lesion is not confidently separate from a normal testis or symptoms are unexplained/persistent.

Management

Do not miss the acute or malignant differential

  • Sudden severe pain or an acutely tender swollen scrotum requires emergency torsion assessment; an intratesticular or inseparable mass requires urgent urological referral.5,3

Confirm the anatomy

  • Palpate the entire testis separately and arrange ultrasound when the diagnosis or testicular examination is uncertain.1,2

Observe or treat symptoms

  • Observe a confidently benign cyst; refer for excision only when symptoms or substantial size/cosmetic impact justify specialist treatment, with fertility-risk counselling.2,4

Exam traps

  • A cyst beside the testis is not the same as an intratesticular tumour.
  • Transillumination is supportive, not a substitute for examining the testis when the anatomy is uncertain.
  • Do not send a suspicious intratesticular mass for transscrotal biopsy; use the urology cancer pathway.
  • A known epididymal cyst does not explain away new acute severe pain.

Illustrations

Transillumination of an epididymal cystA clinical photograph of a scrotal epididymal cyst transilluminating with a torch, with the testis felt separately below.E.dronism, Wikimedia Commons · CC-BY-SA-4.0
Epididymal cyst on ultrasoundAnnotated axial and sagittal scrotal ultrasound showing a small cyst at the head of the right epididymis adjacent to a normal testis, with a small hydrocoele also visible.Cerevisae, Wikimedia Commons · CC-BY-SA-4.0

Key sources

  1. NICE CKS, Scrotal pain and swelling: assessment (UK clinician reference for focused assessment of scrotal pain and swelling; access may require an NHS or professional account)
  2. BAUS, Testicular lump (BAUS patient and clinician-facing overview of examination, ultrasound, benign scrotal swellings, torsion and suspected testicular cancer; page dated March 2024)
  3. NICE NG12, Suspected cancer: recognition and referral (Current recommendations 1.6.7 to 1.6.8: suspected testicular cancer referral and urgent direct-access ultrasound for unexplained or persistent testicular symptoms; last updated 15 April 2026)Published 23 Jun 2015 | Updated 15 Apr 2026
  4. BAUS, Epididymal cyst patient information (BAUS procedure information for excision of an epididymal cyst, including indications and operative risks)
  5. BAUS, Acute scrotal pain (BAUS trainee guidance on recognising testicular torsion and urgent assessment of the acute scrotum)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.