Finding a lump or change in the testicle is alarming and often leads to immediate concern about serious illness. While this anxiety is natural, self-diagnosis is not possible and should not delay professional medical attention. Any new mass, swelling, or discomfort in the scrotum warrants prompt evaluation by a healthcare provider to accurately determine the cause. Only a medical professional can perform the necessary diagnostic steps to distinguish between a harmless condition and a serious diagnosis requiring time-sensitive intervention.
Common Benign Causes
The majority of lumps found in the scrotum are not cancerous and stem from common, non-life-threatening structural issues. Spermatoceles, also known as epididymal cysts, are among the most frequent benign causes. They occur in the epididymis, the coiled tube situated along the back of the testicle. These are typically smooth, fluid-filled sacs that feel like a small, discrete lump separate from the testicle itself. Spermatoceles are generally painless.
A hydrocele involves an accumulation of fluid within the thin sac surrounding the testicle, known as the tunica vaginalis. This condition results in a soft, generalized swelling of the scrotum, which may cause a feeling of heaviness but is usually painless. Hydroceles can develop due to injury, inflammation, or an imbalance in fluid secretion and reabsorption.
A varicocele is an enlargement of the veins within the spermatic cord, often described as feeling like a “bag of worms.” This condition is similar to varicose veins found in the legs and affects about 15% of men. Varicoceles occur most frequently on the left side due to anatomical differences in venous drainage. Though often asymptomatic, a varicocele can sometimes lead to a dull ache or discomfort that may worsen with standing or physical activity.
Causes Related to Infection and Inflammation
Lumps or swelling can also be the result of a rapid inflammatory response, typically caused by infection or sudden mechanical issues. Epididymitis is an inflammation of the epididymis, the tube behind the testicle, most commonly triggered by a bacterial infection, including sexually transmitted infections. This condition usually causes a gradual onset of testicular pain and tenderness, along with possible fever, redness, and swelling of the scrotum.
When the inflammation spreads to the testicle itself, the condition is termed orchitis, or epididymo-orchitis if both structures are involved. Orchitis can be caused by bacterial infections, or sometimes by viruses, such as the mumps virus in post-pubertal males. Symptoms for these inflammatory conditions often include significant pain, a heavy feeling, and sometimes discharge from the penis or blood in the semen.
A separate mechanical cause of acute swelling is testicular torsion, which is a medical emergency. Torsion occurs when the testicle rotates on the spermatic cord, twisting the blood vessels and cutting off blood supply. This results in sudden, severe pain, often accompanied by nausea, vomiting, and a testicle that appears higher or at an unusual angle. Immediate emergency intervention is required to save the testicle if blood flow cannot be restored within a matter of hours.
Understanding Testicular Cancer
While far less common than benign causes, testicular cancer remains a serious concern that must be promptly ruled out. This form of cancer is the most frequent malignancy in males between the ages of 15 and 35, though it can occur at any age. The mass typically arises from germ cells within the testicle itself.
The lump associated with cancer often presents as a solid, firm, and painless mass located directly within the body of the testicle. Unlike fluid-filled cysts, which are usually soft and movable, a cancerous tumor may feel fixed and irregular in texture. Although usually painless, some men experience a dull ache or a sensation of heaviness in the scrotum or lower abdomen.
Factors increasing the risk include a history of an undescended testicle, known as cryptorchidism. Even if the testicle was surgically relocated, the risk remains elevated. A family history of testicular cancer raises the individual risk. Regular self-examination can help notice changes in size, shape, or consistency, facilitating earlier detection.
What to Expect During a Medical Evaluation
A medical evaluation begins with a thorough physical examination, where the healthcare provider assesses the size, location, and consistency of the lump. A technique called transillumination involves shining a bright light through the scrotum. This helps differentiate between a fluid-filled mass, which the light passes through, and a solid mass, which it does not.
The primary tool for definitive diagnosis is the scrotal ultrasound, which uses sound waves to create detailed images of the testicle and surrounding structures. Ultrasound determines if the mass is cystic (fluid-filled) or solid, and whether it originates inside or outside the testicle. Masses inside the testicle are generally more concerning.
For suspected cancer, blood tests are performed to check for tumor markers, such as alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). These proteins can be elevated in the presence of certain testicular cancers. Other blood and urine tests help rule out infectious causes by detecting bacteria or inflammation indicators.