Small cyst or fluid by the testicle seen by chance on an ultrasound
A scrotal ultrasound done for something else, such as checking one side, may mention a small cyst, a little fluid, swollen veins or tiny calcium spots. The NHS says most lumps and swellings in the testicles are caused by something less serious, such as a fluid cyst or swollen veins, though they should always be checked. (NHS lumps) This page covers what the report means, how common each finding is and when guidance suggests follow-up, not treatment.
What the report words mean
- Epididymal cyst. A fluid-filled sac in the epididymis, the coiled tube at the back of the testicle. Most are in its upper part (the head), small and single. (Patil 2015)
- Spermatocele. A similar cyst, often a little larger. A review says it is hard to tell it apart from an epididymal cyst on ultrasound. (Patil 2015)
- Hydrocele. Extra fluid in the thin sac around the testicle. A small amount of fluid there is normal and should not be called a hydrocele. In adults a hydrocele can have no clear cause, or can be a reaction to an infection, injury or a growth. (Patil 2015)
- Varicocele. Swollen veins above the testicle, a bit like varicose veins. Many cause no symptoms and are found by chance. "Subclinical" means it shows on ultrasound but cannot be felt. (ESUR varicocele 2020)
- Testicular microlithiasis. Tiny bright calcium spots inside the testicle. A 2015 European radiology guideline calls it "limited" when there are fewer than 5 spots in one ultrasound view and "classic" when there are 5 or more. (Yilmaz 2024)
How common each finding is
| Finding | How common | Source |
|---|---|---|
| Epididymal cyst | About 30% of people | (Patil 2015) |
| Varicocele | About 15% of men; one on the right side only in under 1% | (ESUR varicocele 2020) |
| Microlithiasis, men aged 18 to 35 | 5.6% of 1,504 healthy men | (Peterson 2001) |
| Microlithiasis, scrotal ultrasounds overall | 0.6% to 9% | (Yilmaz 2024) |
In the study of young men, microlithiasis was found in 4% of white men, 14.1% of Black men, 8.5% of Hispanic men and 5.6% of Asian or Pacific Islander men, and tumour marker blood tests were normal in everyone who had it. The authors noted that testicular cancer is about 1,000 times rarer than microlithiasis. (Peterson 2001) MedlinePlus says testicular cancer is rare and usually happens between the ages of 15 and 40. (MedlinePlus) Studies of adults used for this page did not give a figure for small hydroceles found by chance.
Which ones guidance says need follow-up
- Microlithiasis on its own. The European Society of Urogenital Radiology (ESUR) scrotal imaging subcommittee says follow-up is not advised for microlithiasis alone when there are no other risk factors, and that it is not a reason for regular scrotal ultrasound. (ESUR 2015)
- Microlithiasis with risk factors. The same group advises a yearly ultrasound up to age 55 for people with risk factors. It lists a personal or family history of testicular germ cell cancer, an undescended testicle or surgery for one, and a small (shrunken) testicle. (ESUR 2015)
- Microlithiasis with a lump. If the spots are found together with a mass in the testicle, the guideline advises urgent referral to a specialist centre. (ESUR 2015)
- Varicocele. An ESUR working group says scanning both sides is useful because a small right-sided one is often found with a left-sided one, and suggests also scanning the belly when a varicocele is found only on the right side and can be felt. (ESUR varicocele 2020)
- Cysts and fluid. The NHS says a lump or swelling may not need treatment if it causes no problems and is not getting worse. (NHS lumps)
- Self-checks. The NHS explains how to check your testicles and says to see a GP for a lump or swelling, a testicle getting bigger, a heavy or hard scrotum, an ache or pain, any change that is not normal for you, or a change in the tubes at the back of each testicle. It adds that these symptoms are very common and do not mean you have testicular cancer. (NHS self-check) MedlinePlus says to examine your testicles monthly and get medical care for lumps, redness, pain or other changes. (MedlinePlus)
- Worry is real. See after an abnormal screening result.
The NHS says to go to A&E immediately or call 999 (your local emergency number elsewhere) if you have sudden, severe pain in a testicle, testicle pain along with feeling sick, being sick or pain in your tummy, or testicle pain that has lasted more than an hour or continues when you are resting. (NHS lumps)
Other pages that may help
For checks and symptoms of testicular cancer, see testicular cancer screening. A bulge in the groin on the same scan is covered in a groin or belly button hernia seen by chance, and a soft fatty lump in a fatty lump (lipoma).
Who it applies to
Adults told that a scrotal ultrasound, done for another reason, shows one of these findings. Children, a scan done because of a new lump, pain or swelling, and people already being seen for a testicle condition or for fertility questions are outside this page.
Routine age-based screening
The USPSTF recommends against screening for testicular cancer in adolescent or adult men without symptoms, by a clinician or by self-exam. (USPSTF 2011) See testicular cancer screening and the full list in screenings by age and gender.
Where they differ:
- How long to follow microlithiasis with risk factors. The ESUR guideline advises a yearly ultrasound up to age 55. (ESUR 2015) A 2024 review summarises another approach with regular scans up to age 50 and self-checks after that, because testicular cancer is rare after 50. (Yilmaz 2024)
- Microlithiasis with no risk factors. The ESUR guideline advises no follow-up. (ESUR 2015) The same review lists approaches that range from reassurance alone to regular self-checks. (Yilmaz 2024)
- Belly scan for a varicocele. It is commonly thought that every new varicocele needs a belly scan to look for a growth. The ESUR working group says the evidence does not support this and limits it to an isolated right-sided varicocele that can be felt. (ESUR varicocele 2020)
- Self-checks. The USPSTF recommends against screening by self-exam in men without symptoms. (USPSTF 2011) The NHS explains how to check your testicles, and MedlinePlus says to examine them monthly. (NHS self-check)(MedlinePlus)
Your doctor decides what your result means for you.
Questions people ask
Is a cyst next to the testicle cancer?
An epididymal cyst is a fluid-filled sac in the tube behind the testicle, not cancer. A review says these cysts are found in about 30% of people and are usually small and single. The NHS says most testicle lumps are caused by something like a cyst or swollen veins, but any lump should be checked by a GP. (Patil 2015) (NHS lumps)
What does "small hydrocele" mean?
A hydrocele is extra fluid around the testicle. A tiny amount of fluid there is normal and should not be called a hydrocele. A hydrocele in an adult can have no clear cause, or can follow an infection, injury or a growth. (Patil 2015)
What is testicular microlithiasis?
Tiny calcium spots inside the testicle seen on ultrasound. A study of 1,504 healthy men aged 18 to 35 found them in 5.6%. A European radiology guideline says no follow-up scans are needed when they are found alone and there are no other risk factors. Your doctor decides what your result means for you. (Peterson 2001) (ESUR 2015)
Does a varicocele found by chance need a scan of my belly?
A European radiology working group says a routine belly scan for every new varicocele is not supported by the evidence. It suggests extending the scan to the belly when a varicocele is found only on the right side and can be felt, which is rare. (ESUR varicocele 2020)
When is a testicle problem an emergency?
The NHS says to go to A&E or call 999 for sudden, severe pain in a testicle, testicle pain with feeling or being sick or tummy pain, or testicle pain that lasts more than an hour or continues when you rest. (NHS lumps)