An epididymal cyst is the most common of epididymal masses.
Epididymal cysts have been reported in ~30% (range 20-40%) of asymptomatic individuals 5.
They are usually of lymphatic origin 2. Cysts contain clear serous fluid, lymphocytes, spermatozoa and debris.
Often manifests as a palpable mass. Approximately one-third of patients can be asymptomatic. It may be more prevalent in mountain bikers 3.
They can be solitary or multiple with ~30% having more than one cyst 5.
- cyst contents in uncomplicated cases are anechoic with no internal echoes
- posterior acoustic enhancement may be seen
- well defined anechoic lesions
- larger cysts may contain septations
- larger cyst may displace the testis which is the differentiating point form hydrocele which envelopes the testis
Imaging differential considerations include
- usually has some internal echotexture, but may be indistinguishable from an epididymal cyst
- epididymal cysts may arise throughout the epididymis, while spermatoceles almost always arise in the epididymal head 4
- tunica vaginalis cyst
- paratesticular abscess - will tend to show surrounding inflammatory changes; the clinical context is different
- small hydrocoele to be differentiated from large epididymal cyst with septations
- 1. Black JA, Patel A. Sonography of the abnormal extratesticular space. AJR Am J Roentgenol. 1996;167 (2): 507-11. AJR Am J Roentgenol (citation) - Pubmed citation
- 2. Aso C, Enríquez G, Fité M et-al. Gray-scale and color Doppler sonography of scrotal disorders in children: an update. Radiographics. 25 (5): 1197-214. doi:10.1148/rg.255045109 - Pubmed citation
- 3. Frauscher F, Klauser A, Stenzl A et-al. US findings in the scrotum of extreme mountain bikers. Radiology. 2001;219 (2): 427-31. Radiology (full text) - Pubmed citation
- 4. Dogra VS, Gottlieb RH, Oka M et-al. Sonography of the scrotum. Radiology. 2003;227 (1): 18-36. Radiology (full text) - doi:10.1148/radiol.2271001744 - Pubmed citation
- 5. Woodward PJ, Schwab CM, Sesterhenn IA. From the archives of the AFIP: extratesticular scrotal masses: radiologic-pathologic correlation. Radiographics. 2003;23 (1): 215-40. Radiographics (full text) - doi:10.1148/rg.231025133 - Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Epididymal head cyst||✗|