A testicular lesion is any abnormality, lump, swelling, or mass found on or near a testicle. While the discovery of such a finding often causes immediate fear of malignancy, the majority of these lesions are non-cancerous. Since it is impossible to determine the cause of a lesion at home, immediate medical evaluation for any change in the scrotal area is necessary.
Recognizing Abnormalities and Self-Examination
A lump or swelling is one of the most common signs of a testicular abnormality. Other physical characteristics a person might notice include a feeling of heaviness in the scrotum, a dull ache in the groin or lower abdomen, or a change in the size or consistency of a testicle. Some lesions can also present with pain or discomfort, while the most concerning growths are often painless.
Performing a testicular self-examination helps a person become familiar with what is normal, making it easier to notice changes. The examination is best done during or immediately after a warm bath or shower, when the heat relaxes the scrotal skin. The technique involves gently rolling each testicle between the thumb and fingers, feeling for any hard lumps or variations in size, shape, or firmness. Remember that the soft, cord-like structure at the back of the testicle, the epididymis, is normal and should not be mistaken for a mass.
Common Non-Cancerous Causes
Most scrotal masses are benign, typically involving fluid collection, enlarged veins, or inflammation. These conditions are usually harmless and only require treatment if they cause symptoms like pain or discomfort. A varicocele is an enlargement of the veins inside the spermatic cord, which can feel like a “bag of worms” above the testicle. This condition is more common on the left side and may occasionally be associated with infertility or a dull ache.
Another frequent finding is a hydrocele, which is a collection of fluid in the thin sac that surrounds the testicle. This often results in a painless swelling of the scrotum and can occur due to an imbalance in the fluid’s production or absorption, sometimes following an infection or injury. A spermatocele, or epididymal cyst, is a separate fluid-filled sac that forms within the epididymis, the coiled tube behind the testicle. Spermatoceles are typically painless and benign, containing sperm-containing fluid.
Inflammatory conditions can also mimic a mass, with epididymitis being a common cause of testicular pain and swelling. This condition involves inflammation of the epididymis, often caused by a bacterial infection, such as sexually transmitted or urinary tract infections. Similarly, orchitis is inflammation affecting the testicle itself, often caused by a viral infection like mumps or a bacterial infection. Both conditions cause discomfort and swelling that may be mistaken for a solid mass.
Understanding Malignant Lesions
Malignant lesions, or testicular cancers, most often present as a firm, painless lump or mass located within the testicle itself, rather than outside of it. The presence of a mass within the body of the testicle carries a high suspicion for cancer. Testicular cancer is most common in individuals between the ages of 15 and 35, although it can occur at any age.
These cancers arise from germ cells, the cells responsible for producing sperm. They are broadly categorized into seminomas, which are typically slow-growing, and non-seminomas, which tend to grow more rapidly. Non-seminomas include cell types such as embryonal carcinoma, yolk sac tumor, and choriocarcinoma.
A history of cryptorchidism, or an undescended testicle, is a major risk factor, increasing the chance of developing cancer even if corrected surgically. A family history also plays a role, increasing risk if a brother or father has had testicular cancer. Other risk factors include a personal history of cancer in the other testicle and conditions involving abnormal testicle development.
The Diagnostic Pathway
When a patient presents with a suspicious lesion, the medical evaluation begins with a thorough physical examination. The physician will feel the scrotum to assess the size, location, and consistency of the mass, attempting to determine if it is attached to the testicle or is paratesticular. A small number of patients with malignant tumors may also exhibit gynecomastia, or breast enlargement, due to hormonal changes.
Scrotal ultrasound is the main imaging tool used to evaluate a testicular lesion. The ultrasound helps distinguish between cystic (fluid-filled) masses, which are typically benign, and solid masses, which are concerning for malignancy. It also confirms whether the mass is located inside the testicle or in the surrounding structures.
In cases where cancer is suspected, specific blood tests are ordered to measure serum tumor markers. The three main markers are alpha-fetoprotein (AFP), beta-human chorionic gonadotropin (β-hCG), and lactate dehydrogenase (LDH). Elevated levels of AFP and β-hCG are often seen in non-seminomatous germ cell tumors. These markers are used for initial diagnosis, staging, and monitoring treatment response, but definitive confirmation of cancer requires surgical removal of the testicle for tissue diagnosis.