Epididymal Cysts

oPatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.

Smooth, extratesticular, spherical cysts in the head of the epididymis are not uncommon in adult men. They are benign and do not usually require treatment. It is important to appreciate when they might be significant and when further investigation or treatment is recommended.

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Epididymal cysts usually develop in adults around the age of 40. Epididymal cysts are rare in children and when they occur, usually present around puberty.[1] Cysts are found in as many as 30% of asymptomatic patients having scrotal ultrasound for other reasons, but most of these are spermatoceles.[2] The prevalence in the general population is difficult to estimate.

Patients usually present having noticed a lump. This often causes a great deal of anxiety and clinical examination can enable reassurance.

  • Often epididymal cysts are multiple and may be bilateral.
  • Small cysts may remain undetected and asymptomatic. Small cysts are tolerated by patients. However, once epididymal cysts get large (with size equivalent to the size of a testicle) they are, unsurprisingly, more likely to present for removal.[3]
  • As they are cystic and fluid filled they are well defined, fluctuant and will transilluminate.
  • As they arise in the epididymis, the testis is palpable quite separately from the cyst (unlike a hydrocele where the testis is palpable within the fluid filled swelling).
  • Extratesticular, fluctuant, cystic swellings which transilluminate and are readily palpable separate from the body of the testis are epididymal cysts and do not usually need further investigation.
  • These can readily be distinguished from testicular tumours which arise from the testis.
  • Spermatocele. There is no way clinically to differentiate between a cyst of the epididymis and a spermatocele. They can be differentiated as sperm are present in the milky fluid aspirate of a spermatocele. Such a procedure is not recommended as differential diagnosis does not change management.
  • Inflammatory thickening, either acute or chronic of the epididymis. Such swellings will not transilluminate.
  • Hydroceles. These are collections of fluid surrounding the entire testicle.
  • Varicoceles. These are dilated veins and have been described as feeling like 'a bag of worms'. They increase with increase in abdominal pressure(Valsalva manoeuvre).
  • Other scrotal masses, particularly the extratesticular scrotal masses. These are predominantly benign. Lipomas are the most common extratesticular tumours.[4]

Scrotal ultrasound will assist diagnosis if there is uncertainty.[5][6] Aspiration of fluid is rarely useful or necessary from either a diagnostic or treatment perspective.

  • Cystic fibrosis. Congenital absence of the vas deferens is the most common genital tract anomaly in cystic fibrosis (99% of patients). Epididymal cysts are common.[7]
  • Von Hippel-Lindau disease.[8] Along with other more significant manifestations of this syndrome, epididymal cysts are associated with the condition.[9] It is a rare disease and important to recognise early.[10]
  • Maternal exposure to diethylstilbestrol.
  • Polycystic kidney disease (autosomal dominant).[11]
  • Treatment is not usually necessary and explanation and advice is all that is usually required. Patients should be advised to seek medical advice if epididymal cysts become painful or suddenly start increasing in size.[3]
  • They can be surgically excised. This is best for large or symptomatic epididymal cysts. It is more costly than sclerotherapy and there is a higher rate of postoperative infection and scrotal haematoma. The outcome is better than for other epididymal pathology (such as chronic epididymitis).[12]
  • Treatment by sclerotherapy.[13] Different volumes and types of sclerosant solution can be used although no comparative studies have been done to recommend one sclerosant over another and use of sclerosants other than for varicose veins is usually unlicensed. Sclerosants used include tetracycline, phenol, sodium tetradecyl sulphate,[14][15] polidocanol and ethanolamine oleate. The amount used depends on the size of the cyst.
  • In children, most epididymal cysts involute with time and a conservative approach is recommended.[16]

Torsion of the cyst can occur but is extremely rare with only a handful of cases reported.[17] They do not become infected.[18]

Further reading & references

  1. Chillon Sempere FS, Dominguez Hinarejos C, Serrano Durba A, et al; Epididymal cysts in childhood. Arch Esp Urol. 2005 May;58(4):325-8.
  2. Pais VM et al; Spermatocele, eMedicine, Jun 2009
  3. Walsh TJ, Seeger KT, Turek PJ; Spermatoceles in adults: when does size matter? Arch Androl. 2007 Nov-Dec;53(6):345-8.
  4. Woodward PJ, Schwab CM, Sesterhenn IA; From the archives of the AFIP: extratesticular scrotal masses: radiologic-pathologic correlation. Radiographics. 2003 Jan-Feb;23(1):215-40.
  5. Lee JC, Bhatt S, Dogra VS; Imaging of the epididymis. Ultrasound Q. 2008 Mar;24(1):3-16.
  6. Muttarak M, Chaiwun B; Painless scrotal swelling: ultrasonographical features with pathological correlation. Singapore Med J. 2005 Apr;46(4):196-201; quiz 202.
  7. Blau H, Freud E, Mussaffi H, et al; Urogenital abnormalities in male children with cystic fibrosis. Arch Dis Child. 2002 Aug;87(2):135-8.
  8. Kahn AN et al; Von Hippel-Lindau Syndrome, eMedicine, Feb 2008
  9. Sano T, Horiguchi H; Von Hippel-Lindau disease. Microsc Res Tech. 2003 Feb 1;60(2):159-64.
  10. Joerger M, Koeberle D, Neumann HP, et al; Von Hippel-Lindau disease--a rare disease important to recognize. Onkologie. 2005 Mar;28(3):159-63.
  11. Belet U, Danaci M, Sarikaya S, et al; Prevalence of epididymal, seminal vesicle, prostate, and testicular cysts in autosomal dominant polycystic kidney disease. Urology. 2002 Jul;60(1):138-41.
  12. Padmore DE, Norman RW, Millard OH; Analyses of indications for and outcomes of epididymectomy. J Urol. 1996 Jul;156(1):95-6.
  13. Sigurdsson T, Johansson JE, Jahnson S, et al; Polidocanol sclerotherapy for hydroceles and epididymal cysts. J Urol. 1994 Apr;151(4):898-901.
  14. Freedman D; 'A lovely bunch of coconuts'. Scand J Urol Nephrol Suppl. 1991;138:227-9.
  15. Braslis KG, Moss DI; Long-term experience with sclerotherapy for treatment of epididymal cyst and hydrocele. Aust N Z J Surg. 1996 Apr;66(4):222-4.
  16. Homayoon K, Suhre CD, Steinhardt GF; Epididymal cysts in children: natural history. J Urol. 2004 Mar;171(3):1274-6.
  17. Yilmaz E, Batislam E, Bozdogan O, et al; Torsion of an epididymal cyst. Int J Urol. 2004 Mar;11(3):182-3.
  18. Gunaydin G, Ozyurt C, Kocak I, et al; Anti-bacterial activity of the fluid contents of spermatoceles and epididymal cysts. Br J Urol. 1995 Jan;75(1):68-70.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.

Original Author:
Dr Richard Draper
Current Version:
Last Checked:
Document ID:
1108 (v23)