Testicular Cancer

What is Testicular Cancer?

Testicular cancer occurs when normal, healthy cells, which are carefully regulated by the body, begin to reproduce uncontrollably within an area of the body such as the testicles.

  • Around 2400 men will be diagnosed with testicular cancer in the UK each year
  • Over 21,000 men will be diagnosed in Europe each year and around 55,000 globally
  • It most commonly affects men between the ages of 15-45 and is statistically the most common cancer in men aged between 25-49 in the UK (Cancer Research UK)
  • Around 47% of men diagnosed will be under the age of 35
  • 98% of men will be alive 10 years after treatment
  • Around 60 young men will die of testicular cancer each year.




For more information on testicular cancer please click on the video link below.

Risk Factors

Unlike many cancers, there are few known strong risk factors for testicular cancer. While most of these cancers occur in unsuspecting individuals, some risk factors can be traced in a minority of cases.

These include:

  • Men born with an undescended testicle (cryptorchidism) where the testicle fails to descend into the scrotum. The testicles of a male baby form in its abdomen while in the mother’s womb and normally descend into the scrotum at birth or shortly afterwards. Around 10% of men diagnosed with testicular cancer may have a history of this condition. Although it can be corrected using a minor surgical technique during childhood (an operation called an orchidopexy)  the risk of developing testicular cancer still remains greater.
  • Pre-cancerous cells found inside the testicle known as carcinoma in situ (CIS). They may be found when a man has a testicular biopsy for instance during investigations into infertility. Also referred to as intratubular germ cell neoplasia (IGCN). There is a 50% chance that these cells will develop into testicular cancer within 5 years.
  • A brother or father affected by testicular cancer. Some research has indicated that there may be direct genetic factors involved in this process.

Brother                                                                                                    Father                       

Brother                  Father                                                      

  • A previous history of testicular cancer. Like all cancers there is always a risk that it can return. However if testicular cancer does reoccur there is every chance that it can still be cured using further treatments such as chemotherapy
  • Research suggests that testicular cancer is slightly more common in men who have fertility problems resulting in poor or abnormal sperm
  • Caucasian men have a higher risk of testicular cancer than men from other ethnic groups
  • Men with HIV are more likely to develop testicular cancer.

Other possible factors

  • There is some evidence to suggest that men who are taller than average have a slightly increased risk of developing testicular cancer.
  • Twins have an increased risk of testicular cancer, especially if identical. But as testicular cancer is rare the risk remains low.
  • A build-up of calcium in the testicles called microlithiasis. Some studies have shown that in certain circumstances a small percentage of men with this condition may go on to develop testicular cancer.

Controversial Factors

  • A sedentary (not very active) life style may increase the risk of testicular cancer as it may do for other types of cancer and poor health in general.
  • Repeated trauma to the testicles (rather than inevitable knocks or one blow) may increase the risk. However most recent research has concentrated on single trauma rather than repeated trauma or knocks to the testicles.
  • Several small research studies have also suggested that men who smoke marijuana regularly and develop testicular cancer are more likely to suffer from a more aggressive form of the disease.

For more information on the risk factors for testicular cancer please click on the video below.


What are the Testicles?


The testicles are two small oval shaped organs which can also be called the testes or gonads and are the male sex glands which hang down behind the penis, in the scrotum. It’s quite normal for one testicle to be slightly larger than the other, although the size and shape should be roughly the same. It can also be normal for one to hang a bit lower than the other.

The testicles start growing in size at around the age of 11-12 and by early adulthood reach their final size. They produce sperm and approximately 90% of testosterone, the male sex hormone and are located outside of the body in the scrotum because sperm develop best at a temperature several degrees cooler than normal internal body temperature.

The testicles contain structures called seminiferous tubules which produce cells called germ cells. These in turn produce sperm. The sperm move into the epididymis (a tube running behind the testicle) where they mature. They get stored there for a few weeks and combine with fluids from other areas (the prostate and seminal vesicles) to form semen.

The leydig cells distributed throughout the testicles are the body’s main source of testosterone.

For further information on the function of the testicles click on the video link below.

What is Testosterone?

Testosterone is the male sex hormone and is essential for the development of the reproductive organs and other male characteristics such as:

  • Body and facial hair
  • Low voice
  • Muscle development
  • The ability to have an erection
  • Sex drive (libido)
  • Stamina
  • Mood and wellbeing


Without enough testosterone a man may lose his sex drive, suffer from fatigue, low mood and put on weight. Testosterone is commonly associated with male aggression but in reality it is a hormone that helps men deal with the stress and strain of everyday life. Keeping fit and avoiding too much fatty fried food, sugar and caffeine all of which can reduce testosterone levels, can keep levels healthy.

Signs and Symptoms of Testicular Cancer

  • A small pea sized lump can be felt in around 90% of cases and in over 80% of cases this will be painless
  • Dragging sensation, ache or pain (more common in non cancerous conditions)
  • Recent history of trauma (10%), leading to examination and discovery of a lump
  • Breast swelling or tenderness (called gynaecomastia). This is rare but may be caused by hormones which are produced by some types of testicular cancer. Similar symptoms can be caused simply by body changes during puberty (growing pains)
  • Back pain caused by enlarged lymph nodes in the back (see below).

Lymph Nodes

The human body is covered by a special type of drainage system called the lymphatic system. This system is responsible for transporting excess fluid from the organs and tissues of the body in a fluid called lymph. Lymph fluid will contain various types of cells and substances that are no longer needed by the body. The lymph fluid will be transported through the lymphatic drainage system and pass through small nodules or nodes that act as filters. These are responsible for filtering out the unwanted substances. Cancerous cells which break off from the an organ which has cancer and can also travel along this route and become trapped at the lymph nodes where they can then accumulate and infiltrate a new area of the body.

Lymphnodes TC

Non-cancerous Conditions

Testicular cancer is usually initially identified as a lump in the testicle, but there are also a number of non-cancerous conditions which can affect younger men. These may often have similar symptoms to testicular cancer and may cause worry.

Around 96% of abnormal testicular conditions (lumps and bumps) will not be cancerous.



This is inflammation of the epididymis and /or testis, which is usually due to infection. It is particularly common in young males aged 15-30 and may occur as a result of a urinary infection or sexually transmitted disease (STI). Swelling tends to occur quite rapidly and is painful and may take some weeks to fully settle. A 2-week course of strong antibiotics will usually be prescribed.



This is a collection of dilated veins in the scrotum (think varicose veins). It often affects men between the ages of 15-25 and occurs next to and above one or both of the testicles. It involves the spermatic cord which carries sperm from the testes to the penis and which also contains blood vessels and nerves. Normally the veins in the spermatic cord are undetectable. When they become distended they have been medically described as feeling like a “bag of worms”! Varicoceles can vary in size and are usually not painful but may cause a “dragging” sensation. They may affect 15% of the male population and are associated with male infertility.



The testis is surrounded by a protective tissue sac, which produces a lubricating fluid to allow the testicles to move freely. Excess fluid usually drains into the veins in the scrotum. However, if this drainage route has been affected by infection or trauma, fluid may accumulate and is called a hydrocele. A hydrocele will often feel like a small fluid filled balloon and may cause a chronic ache or discomfort. It can often be surgically repaired if it becomes too problematic or too big, but is usually treated depending on whether bothersome symptoms are present.

Epididymal cysts


These are small fluid filled cysts, which may contain semen. They are usually about the size of a pea but can be larger. They usually develop in adults around the age of 40 and may take many years to form. They are smooth and spherical and tend to be found in the head of the epididymis. They are not cancerous. They can be surgically removed if they become too big or painful.

To watch a video describing these conditions please click the video below.

Testicular pain

There are several factors which can be involved including stress, wearing underwear that is too tight as well as sexual arousal with an erection but without ejaculation (also known as blue balls). Physical activity can sometimes cause strain injuries in the lower back and groin which may cause nerve pain which may be felt as pain in the testicles. Pain from blue balls will usually go after a few hours while chronic sports damage may need further input from a GP or physiotherapist.

For more information on testicular lumps or abnormalities please click here for information from the British Association of Urology Surgeons (BAUS).

Testicular Self Examination

This is the easiest way to identify any potential testicular problems and testicular cancer. It only takes a few minutes to perform and gives men a good excuse for feeling their balls (like they need one!). It is good to check every now and then after a bath or shower when the scrotum will be warm, relaxed and pleasant to touch. If there are any risk factors present then checking more regularly may be of benefit.

It is important that men are aware of what is normal for their testicles. It is normal for one testicle to  hang down slightly lower than the other or be slightly bigger. Both should however be roughly the same size and smooth to the touch.

  • Check each testicle separately using one or both hands (Figure 1).


Fig 1 The entire surface of both testes is felt carefully.

  • Roll each testicle between the thumb and forefinger to check that the surface is free of lumps or bumps. Do not squeeze!
  • Get to know your balls; their size, texture, anatomy, magnificence. Identify the epididymis or sperm collecting tube, often mistaken for an abnormal lump that runs behind each testicle (Figure 2).


Fig 2 The epididymis runs behind the testicles

To watch a video on TSE please click the image below (warning male nudity).

Men should:

  • Perform testicular self-examination on a regular basis for instance monthly.
  • Get to know their balls; what is normal for them and the general anatomy of the testicle.
  • If they find anything unusual such as a lump or swelling in their testicles they should get it checked by their GP. The likelihood is that it will not be testicular cancer but cancer still needs to be ruled out. Do not delay getting checked out, as in rare circumstances some types of testicular cancer can progress quickly. If a GP is unsure of the exact cause of an abnormality they will usually request an ultrasound scan of the scrotum. The ultrasound scan and referral will usually be made on an urgent basis and the results should be available within a few weeks. Around 96% of abnormalities found affecting the testicles will not be cancerous.

Getting any abnormalities checked quickly rather than leaving things will lead to a greater chance of cure if testicular cancer is present and will also show what is causing the problem which if non-cancerous will lead to peace of mind.


To download a testicular cancer awareness Z-card please click here 


Last reviewed November 2019. Next review November 2020.


References available on request.

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