Scrotal lumps

Lumps in the scrotum are quite common and most of them are not serious. However, if you do discover a lump then you should seek the advice of a doctor who will be able to advise whether further tests are needed. The usual test employed to investigate scrotal lumps is an ultrasound scan, which is a painless scan performed by a radiographer or radiologist.

Common causes of scrotal lumps include:

  • Swellings in the scrotal skin
  • Large hernias
  • Hydrocoele (fluid around the testicle)
  • Epididymal cyst
  • Infections of the testis or epididymis
  • Testicular cancer

Swellings in the scrotal skin

Lumps can arise from the sweat glands in the scrotal skin and are referred to as sebaceous cysts. Typically they form swellings 1-2 cms in diameter. Occasionally they can discharge white toothpaste like material. They can also get infected so that you get a small abscess in the skin. If treatment is required, then the cysts can be removed with a straight forward minor operation done under local anaesthesia.


Hernias are due to weakness in the abdominal wall, and usually originate in the groin. Sometimes if they enlarge they may protrude down into the scrotum. They are best treated by an operation performed by a specialist hernia surgeon, who will often be able to perform the procedure by a keyhole technique.


A hydrocele is a collection of fluid around the testicle. We don’t understand in most patients why the fluid begins to collect, but once it begins slowly over months or years, the swelling increases in size and can become very large. Once they have started to form they do not go away. Hydroceles are not dangerous but may cause a degree of physical discomfort. They are usually treated by a simple operation under anaesthetic which can usually be performed as a day case procedure.

Epididymal cysts

These are sometimes called spermatoceles and originate from the sperm sac adjacent to the testis which is called the epididymis. We do not know why they form. They are very common, being found in 1 in 3 men. Again, once formed, they very rarely disappear and may continue to grow. They are not harmful but give some discomfort and are a nuisance with activity and bending. If the cysts are large and uncomfortable, they can once again be removed with a simple day-case operation under anaesthesia.

Infections of the testicles

Infection of the testis and epididymis is called epididymo-orchitis. It is a painful infection often associated with a fever and alteration of the way you pass urine as the germs may have spread from the bladder into the testis. In young patients below the age of 35 the commonest cause is a sexually transmitted infection, such as chlamydia or gonorrhoea. Your doctor will probably recommend that you are seen in the Genito Urinary Medicine Department for necessary tests and investigation of your partners. Infection will resolve with antibiotics.

In older men, infection is usually due to a bacteria which causes urinary tract infections (UTIs). This is usually a more severe infection than chlamydia quite often associated with a lot of swelling and redness of the skin. Sometimes abscesses can form and patients require admission to hospital and on very rare occasions, surgical intervention to drain an abscess is required. Recovery is usually complete with antibiotics but it may take many weeks for the swelling to resolve.

Testicular cancer

Testicular cancer is not common, but it is important to get things checked if you find any lumps or bumps in the testicle. Testicle cancer usually affects young men (ie 15-45 years old) but can affect men of other ages too. For further information, please see the more detailed section in the “Urological cancers” section.

Further Resources

  1. Information on scrotal lumps from the British Association of Urological Surgeons (BAUS):