Scrotal lumps and swellings: causes and when to worry

The scrotum is the bag of skin that holds the testicles. Within it, each testicle sits beside the epididymis, a coiled tube that stores and carries sperm, with the spermatic cord above. Lumps can arise from the skin of the scrotum, from these structures or from the testicle itself. NHS inform notes that lumps and swellings in the testicles are relatively common, and that it is important to know what is normal for you so you can notice changes.

BAUS groups swellings into cystic (fluid-filled), inflammatory and solid, and says clinical examination and ultrasound can usually separate them. A hernia in the groin can also extend towards the testicle, though examination shows it does not arise from the scrotum itself.

BAUS says these are the commonest and are usually caused by a hydrocele (fluid around the testicle), a cyst in the epididymis, or varicose veins above the testicle (a varicocele). They are all benign and only need treatment if they cause significant symptoms. NHS inform describes varicoceles as soft lumps that develop gradually above the testicle and on the left side of the scrotum, and epididymal cysts as small, smooth, fluid-filled swellings that slowly develop in the epididymis.

For problem symptoms, BAUS says hydrocele repair, excision of an epididymal cyst, and open surgery, keyhole surgery or radiological embolisation for varicocele may be needed. Otherwise no treatment is necessary.

The NHS describes epididymitis as a swollen, painful epididymis, often caused by infection and usually treated with antibiotics. It says the cause is usually a sexually transmitted infection in men under 35, and usually a urine infection in men over 35. NHS inform lists epididymo-orchitis, where the testicle is inflamed too, as caused by bacterial infections such as UTIs, STIs and mumps. BAUS says mumps involvement usually needs only painkillers.

Testicular torsion, where the spermatic cord twists and cuts off the blood supply, is a different matter. BAUS says suspected torsion requires emergency admission and immediate surgery, and NHS inform describes it as benign but serious. Do not wait to see if severe pain settles.

BAUS lists solid swellings including rare infections such as tuberculosis and syphilis, a sperm granuloma after a vasectomy, chronic epididymitis, and a testicular tumour. A lump attached to the surface of the testicle is probably benign. A lump within the testicle itself carries, in BAUS's words, a 90% chance of being testicular cancer.

BAUS says testicular cancer is the commonest malignant tumour in men aged 20 to 50, is rare over 50 though certain forms occur, and is more common in abnormal testicles such as those that were undescended, injured or infected, or small and soft. If a GP suspects cancer you may be referred urgently under the 2-week-wait system.

BAUS suggests examining yourself when warm and relaxed, for example after a bath or shower. Stand in front of a mirror and hold each testicle in turn between your fingers, feeling the body of the testicle and all the structures attached to it. Learn your own baseline so that a change stands out.

• A new lump, however small.

• Swelling, or one testicle becoming bigger than the other.

• A change in the shape or feel of a testicle.

• Aching or discomfort that does not go away.

BAUS says a GP will take a full history, paying particular attention to past injury, infection or testicular surgery, and examine the scrotum, abdomen and lymph glands. NHS inform says a doctor may look at and feel the testicles, shine a torch through the scrotum to check for fluid, arrange an ultrasound scan, and test a urine sample if infection is suspected.

If cancer is suspected, BAUS says blood tests for tumour markers (alpha-fetoprotein, beta-human chorionic gonadotrophin and lactate dehydrogenase) may be arranged, and a CT scan of the abdomen and chest may follow depending on the ultrasound findings. The NHS says sexual health clinics can also assess and treat epididymitis, often with walk-in access.

Phone 999 or go to A&E for sudden, severe testicular pain, pain with nausea, vomiting or tummy pain, or pain lasting more than an hour or continuing at rest, according to NHS inform. Contact your GP practice urgently for a lump, swelling, change in shape or feel, one testicle larger than the other, or persistent aching. Do not drive yourself to A&E if in severe pain.