Testicular lymphoma is a rare and aggressive form of non-Hodgkin lymphoma that originates within the testicles. This type of cancer is considered a primary extranodal lymphoma, meaning it starts outside of the lymph nodes. It represents a small percentage of all non-Hodgkin lymphomas, typically accounting for 1% to 2% of cases.
Understanding Testicular Lymphoma
Testicular lymphoma is an uncommon cancer, making up less than 5% of all testicular malignancies, but it is the most frequently diagnosed testicular cancer in men over 60 years old. While it primarily affects older men, it can occur at any age. The most prevalent type of testicular lymphoma is diffuse large B-cell lymphoma (DLBCL), which accounts for the majority of cases.
This lymphoma subtype is known for its aggressive clinical behavior and its tendency to spread early, particularly to the central nervous system (CNS) and the contralateral testicle. Testicular DLBCL often arises in the immune-privileged site of the testis. Its aggressive nature and tendency for extranodal relapse highlight the importance of specific management strategies.
Recognizing the Signs
The most common symptom of testicular lymphoma is a painless swelling or lump in one testicle. This enlargement may also be accompanied by a feeling of heaviness in the scrotum. While pain is less common, some individuals might experience sharp pain.
These symptoms can be non-specific and similar to other conditions, which can make early diagnosis challenging. Men should perform regular self-examinations. Any new lump, swelling, or noticeable change in a testicle should prompt a medical consultation.
How Testicular Lymphoma Is Diagnosed
The diagnostic process for testicular lymphoma begins with a physical examination, where a healthcare provider examines the testicles for abnormalities and checks for swollen lymph nodes in the groin, abdomen, armpits, and neck. If a lump is detected, a scrotal ultrasound is the next step. This imaging uses sound waves to create pictures of the testicles and helps determine if a mass is present and whether it is inside or outside the testicle.
To confirm the diagnosis, a radical inguinal orchiectomy, the surgical removal of the affected testicle through an incision in the groin, is performed. A needle biopsy is avoided for testicular masses due to the risk of spreading cancer cells. The removed testicle is sent for pathological examination to identify the specific type of lymphoma.
Following diagnosis, staging procedures determine if the lymphoma has spread. These include CT scans of the chest, abdomen, and pelvis to check for enlarged lymph nodes or other affected organs. PET scans are also helpful in staging and evaluating treatment response.
A bone marrow biopsy may be performed to check for lymphoma involvement. A lumbar puncture, also known as a spinal tap, is done to collect cerebrospinal fluid for analysis, as CNS involvement is a known risk with testicular lymphoma.
Treatment Approaches
Initial treatment for testicular lymphoma involves a radical inguinal orchiectomy, the surgical removal of the affected testicle. This procedure serves both as a diagnostic tool and a primary therapeutic intervention. Following surgery, systemic chemotherapy is the main component of treatment due to the aggressive nature of testicular lymphoma and its high risk of spreading. The standard chemotherapy regimen is R-CHOP, which combines Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone, administered in six to eight cycles.
Central nervous system (CNS) prophylaxis is an important aspect of treatment for testicular lymphoma because of the high risk of CNS relapse. This is achieved through intrathecal chemotherapy, where chemotherapy drugs like methotrexate are injected directly into the spinal fluid. High-dose systemic chemotherapy with agents like methotrexate may be used for CNS prophylaxis. Radiation therapy to the contralateral testicle (the unaffected testicle) is also a standard practice to prevent recurrence in that site, as the disease has a tendency to disseminate there. Radiation therapy, administered after chemotherapy, involves a dose of around 30.6 Gy in 17 daily fractions.
Prognosis and Long-Term Care
Despite its aggressive nature, the prognosis for testicular lymphoma has improved with appropriate multi-modal treatment. Factors influencing prognosis include the stage of the disease at diagnosis and the patient’s overall health. Early-stage disease may have a higher five-year survival rate compared to advanced disease.
Long-term follow-up and surveillance are important due to the continuous risk of recurrence, which can occur even years after initial treatment. Common sites of relapse include the central nervous system (CNS) and the contralateral testicle. The 10-year cumulative risk of all relapses can be as high as 55%, with CNS and contralateral testicular relapses having a cumulative risk of approximately 21%. Quality of life considerations after treatment are addressed, as ongoing medical care is a part of managing this condition.