Finding a bump on your testicles or within the surrounding scrotal sac can be a source of immediate anxiety. While it is natural to worry, a large majority of such masses are caused by non-cancerous conditions. However, because a lump can, in a small number of cases, be a sign of a serious health concern, it is important to seek a professional medical evaluation for any new or changing mass. A healthcare provider can accurately determine the cause and recommend necessary treatment or monitoring.
Identifying the Source Skin Versus Internal Structures
The location of a mass provides the first important clue about its origin. A bump that is visibly on the surface of the scrotal skin, moving with the skin when gently touched, likely arises from a superficial skin structure. These masses are generally related to hair follicles, skin glands, or other external skin issues.
A mass felt beneath the skin, within the scrotum, originates from the testicle itself or surrounding internal structures. These structures include the epididymis—a coiled tube at the back of the testicle that stores and transports sperm—and the spermatic cord, which contains blood vessels and the vas deferens. Distinguishing between a surface bump and an internal mass is the first step in understanding the potential cause.
Common Non-Cancerous Causes
Many common scrotal masses are benign and involve the accumulation of fluid or dilated veins rather than solid tissue growth. One frequent cause is an epididymal cyst, often called a spermatocele, which is a fluid-filled sac that develops in the epididymis. These cysts are typically smooth, contain fluid that may include sperm, and are harmless, though they can sometimes grow large enough to cause a sensation of heaviness.
A hydrocele represents another common fluid-related swelling, resulting from the collection of fluid between the layers of tissue surrounding the testicle. Hydroceles are usually painless and feel like a smooth, water-filled balloon. They can be caused by injury or infection in adults, or sometimes occur without a known cause. Varicoceles are also common, involving an enlargement of the veins within the spermatic cord, often described as feeling like a “bag of worms” above the testicle. This condition is caused by faulty valves in the veins and is generally not serious unless it causes discomfort or affects fertility.
Superficial bumps on the scrotal skin are frequently due to sebaceous cysts or ingrown hairs, which are minor issues related to the skin’s oil glands and hair follicles. Sebaceous cysts form when a gland becomes blocked, creating a slow-growing, firm lump just under the skin’s surface. Folliculitis or ingrown hairs can cause small, reddish bumps similar to a pimple that are temporary and resolve on their own.
Signs Requiring Urgent Medical Attention
While most lumps are benign, certain signs must prompt an immediate medical evaluation to exclude time-sensitive conditions. A hard, painless lump located directly within the body of the testicle itself is the most important sign associated with testicular cancer. Unlike masses in the epididymis or spermatic cord, a true testicular tumor often feels like a firm irregularity or an area of increased firmness within the testicle.
Acute, severe pain in the testicle that comes on suddenly, sometimes accompanied by nausea or vomiting, can indicate testicular torsion. This condition involves the twisting of the spermatic cord, which cuts off the blood supply and requires emergency surgery within hours to preserve the organ.
Any rapid swelling or pain accompanied by fever and chills suggests an infection, such as epididymitis or orchitis, which are inflammations of the epididymis or testicle, respectively. A lump that grows rapidly or feels fixed and immovable may also be concerning, as this presentation differs from the slow-growing, often mobile nature of benign cysts. Additionally, a heavy or dull aching sensation in the scrotum that persists or a noticeable change in the size or shape of the testicle should be investigated by a physician.
What to Expect During a Medical Examination
A medical examination for a scrotal mass usually begins with a thorough physical assessment. The healthcare provider will carefully look at and palpate, or feel, the scrotum to determine the exact location, size, texture, and mobility of the mass. They will attempt to determine if the mass is within the testicle, attached to the epididymis, or separate from both structures.
A technique called transillumination may be used, where a light is shone through the scrotum. Fluid-filled sacs like hydroceles will typically transmit the light, appearing translucent, while solid masses will block the light. The definitive diagnostic tool is the testicular ultrasound, which uses high-frequency sound waves to create detailed images of the internal structures. This non-invasive scan is highly accurate at differentiating between fluid-filled cysts and solid tumors.
If the ultrasound suggests a solid mass or a tumor, blood tests may be ordered to check for specific proteins known as tumor markers. These markers, which include alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (\(\beta\)-HCG), can be elevated in the presence of certain types of testicular cancer.