The discovery of a lump in the scrotum is understandably concerning, yet many scrotal masses are not serious. The structure of the scrotum is complex, containing the testicles, blood vessels, and tubes that transport sperm, meaning lumps can arise from any of these components. While this information explores potential causes, any new or changing mass requires prompt evaluation by a healthcare provider. Only a medical professional can perform the necessary physical examination and diagnostic tests, such as an ultrasound, to determine the exact cause and recommend appropriate treatment.
Common Benign Scrotal Causes
Many scrotal lumps are a result of fluid accumulation, enlarged veins, or non-cancerous cysts, which are generally harmless. One of the most common findings is a spermatocele, also known as an epididymal cyst, which is a painless, fluid-filled sac that forms in the epididymis, the coiled tube located behind the testicle. This cyst typically contains fluid and may include sperm, often presenting as a smooth, separate lump above or behind the testicle. Spermatoceles rarely cause discomfort unless they grow large, and they generally do not require treatment.
Another frequent cause is a hydrocele, a collection of fluid that accumulates in the thin sheath surrounding the testicle. Hydroceles cause a painless swelling of the entire scrotum or one side, often resulting in a feeling of heaviness or bulkiness. In adults, they can develop due to injury, inflammation, or infection. They are typically diagnosed by transillumination, where a light shone through the scrotum shows the fluid-filled nature of the mass.
Varicoceles are also very common, representing an enlargement of the veins within the spermatic cord, similar to varicose veins in the legs. These masses are often described as feeling like a “bag of worms” and are typically found above the testicle, most frequently on the left side. They can cause a dull ache or heavy sensation, particularly after physical activity or prolonged standing. While benign, they can sometimes be associated with fertility concerns.
Lumps Caused by Inflammation or Infection
Lumps that appear with a rapid onset of pain, heat, or redness often indicate an underlying inflammatory or infectious process. Epididymitis is the inflammation of the epididymis, the tube behind the testicle, and it is a common cause of acute scrotal pain and swelling. The lump associated with epididymitis is characterized by tenderness, warmth, and firm swelling at the back of the testicle, which can quickly spread to involve the entire testicle.
This condition is most frequently caused by a bacterial infection. The infection can also spread to the testicle itself, a condition called orchitis, which causes swelling and pain directly within the testicle. When both the epididymis and the testicle are involved, the condition is termed epididymo-orchitis.
Accompanying symptoms often include fever, chills, discomfort during urination, or discharge from the penis, all of which point toward an active infection requiring prompt antibiotic treatment. Inflammation can also lead to a reactive hydrocele, where fluid accumulates around the testicle. A less common cause is a viral infection, such as mumps, which can sometimes lead to orchitis.
Testicular Cancer and High-Risk Masses
While most scrotal lumps are benign, the most serious cause is testicular cancer, which typically presents as a mass originating within the testicle itself. The most common presentation is a painless, firm lump or swelling on one testicle, often detected during self-examination. Unlike benign masses that are separate from the testicle, a cancerous mass is usually fixed and represents an abnormal growth within the testicular tissue.
The tumor often causes a noticeable change in the size, shape, or texture of the testicle, making one testicle feel significantly firmer or heavier than the other. Although the mass is frequently painless, some individuals report a dull ache or feeling of heaviness in the groin or scrotum. Testicular cancer is relatively rare but is the most common cancer in younger individuals, primarily affecting those between the ages of 15 and 45.
Risk factors include a history of cryptorchidism, or undescended testicles, even if surgically corrected. A family history of the disease also increases the risk. Early diagnosis is extremely important, as testicular cancer is highly treatable, even if it has spread beyond the testicle.
Red Flags: When to Consult a Healthcare Provider Immediately
Certain symptoms associated with a scrotal lump indicate a medical emergency. Sudden, severe pain in a testicle, particularly if accompanied by nausea or vomiting, should prompt an immediate visit to an emergency room. This combination of symptoms can indicate testicular torsion, a condition where the spermatic cord twists, cutting off blood supply to the testicle.
Any lump or swelling accompanied by a high fever and chills also warrants urgent medical evaluation, as this suggests a severe, rapidly progressing infection. Additionally, rapid swelling, significant redness or bruising of the scrotum, or pain that does not subside after an hour of rest are concerning signs. These symptoms require immediate professional assessment to prevent potential complications like the loss of a testicle or the spread of infection.