Written By: Devin Golden
Testicular Mesothelioma
Testicular mesothelioma is a rare cancer of the membrane surrounding the testes. This type of mesothelioma accounts for less than 1% of all cases of mesothelioma. Due to the rarity of this type of mesothelioma, the prognosis is typically poor and treatment options are limited. Management of the disease generally involves surgical removal of the affected testicle (orchiectomy), sometimes followed by chemotherapy or radiation.
Medically Reviewed By
Dr. Stephen Williams
Precision Oncology Scientist
Medically Reviewed By
Dr. Stephen Williams
Precision Oncology Scientist
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Important Facts About Testicular Mesothelioma
- Testicular mesothelioma forms in the lining surrounding the testes, which is composed of two tissue layers: the tunica albuginea and the tunica vaginalis.
- There is limited data available regarding testicular mesothelioma, which is due to the rarity of the cancer.
- Surgery is often the first line approach to treatment for testicular mesothelioma.
What Is Testicular Mesothelioma?
Testicular mesothelioma is a rare cancer in which tumors first form in the tunica vaginalis, which is the outer layer of the two protective membranes surrounding the testes. Medically termed “mesothelioma of the tunica vaginalis testis,” this cancer is caused by asbestos exposure. It is the least common form of mesothelioma, with fewer than 1% of all cases.
Example of Testicular Mesothelioma Development
There are fewer than 100 documented cases reported in medical literature, according to the American Cancer Society Journals. Most diagnosed patients are between 55 and 75 years old, though approximately 10% of cases have occurred in individuals younger than 25.
The disease often presents as a painless scrotal mass or hydrocele (fluid accumulation in the scrotum) which can complicate early detection. Due to its rarity, the disease remains poorly understood, and ongoing research is focused on identifying risk factors, improving diagnostic accuracy, and developing more effective treatment approaches.
How Does Testicular Mesothelioma Develop?
Testicular mesothelioma develops when mesothelial cells in the tunica vaginalis – the membrane surrounding the testes – undergo genetic changes as a result of chronic inflammation from exposure to asbestos. Several case studies and reviews, including a 2019 analysis published in Frontiers in Oncology, define an association between asbestos exposure and testicular mesothelioma tumors.
Inhaled or ingested asbestos fibers can travel through the lymphatic system and become lodged in the tunica vaginalis, where they cause long-term irritation. Over time, this irritation can lead to genetic mutations in cells, triggering unregulated cell growth and tumor formation.
A review of clinical cases published in the Journal of Clinical Oncology indicated that once malignant mesothelial cells begin to multiply, they can invade surrounding tissues and, in advanced stages, metastasize to lymph nodes and distant organs. Since mesothelial linings help reduce friction and support organ mobility, tumor development in these membranes can impair organs. Early detection is crucial for successful treatment.
Is Asbestos Exposure the Cause of Testicular Mesothelioma?
Testicular mesothelioma remains one of the rarest forms of mesothelioma – fewer than 300 cases reported globally.
Two studies provide further insight into the link between asbestos and testicular mesothelioma:
- According to an Italian study, around 27% of testicular mesothelioma cases involved a known history of asbestos exposure.
- In an American study of 74 testicular mesothelioma cases, only 25 (34.2%) involved a known history of asbestos exposure.
Italian Study
American Study
Many people with mesothelioma were unknowingly exposed to asbestos – such as through secondary exposure from family members who directly worked with asbestos or by living in environments containing deteriorating asbestos materials.
Symptoms of Testicular Mesothelioma
Recognizing the symptoms of testicular mesothelioma is crucial for early detection and treatment. While this rare form of cancer often presents with subtle symptoms, the following are the most common indicators:
- Hydrocele – The build-up of fluid around the testes is the most frequent symptom of testicular mesothelioma. This buildup causes the scrotum to swell and can lead to noticeable discomfort plus changes in the testes’ appearance.
- Groin or testicular pain – As the fluid accumulates and tumors develop, pressure on the surrounding tissues can cause pain in the groin or testicular area. This pain is often described as a dull ache but can intensify as the tumor grows.
- Swelling of one or both testicles – Swelling in the scrotum can be caused by tumors or fluid buildup. In some cases, the swelling may be found on only one side, although both sides may become swollen as the disease progresses.
Because testicular mesothelioma is rare, these symptoms can easily be mistaken for more common conditions, such as an inguinal hernia or epididymitis, which can delay diagnosis. If these symptoms are noticed, it is important to consult a healthcare professional for a thorough examination and diagnostic testing.
Early intervention may help reduce the risk of mesothelioma spreading beyond the testes and resulting in further health complications.
Treatment for Testicular Mesothelioma
Treatment for testicular mesothelioma is similar to treating the other types of mesothelioma. Surgery can be the most effective treatment method to remove the diseased tissue.
Additional methods like chemotherapy, immunotherapy and radiation can control the growth of the disease or prevent recurrence. These methods can be with surgery, or if surgery is not an option.
Surgery for Testicular Mesothelioma
Surgery is the most effective treatment for testicular mesothelioma, particularly when the cancer is localized to the testes. If tumors are confined to this area, removing the affected tissue offers the best chance for controlling the disease.
The most aggressive and common surgical procedure is an inguinal orchiectomy (also known as orchidectomy), which is the removal of one or both testicles, the surrounding tissue lining (tunica vaginalis), and the spermatic cord. Surgeons create an incision in the groin to carefully remove the cancer.
If the mesothelioma has spread to nearby lymph nodes, the surgical team may perform a lymph node dissection to remove affected nodes, which can help prevent further metastasis. However, once the cancer spreads beyond the testes, treatment becomes more complex, as mesothelioma tends to resist chemotherapy and other therapies. In advanced cases, surgery combined with chemotherapy or radiation therapy can manage the disease.
Surgical intervention for testicular mesothelioma carries risks, and the extent of surgery required depends on the tumor’s stage and location. Early detection and surgery can improve survival rates.
Chemotherapy for Testicular Mesothelioma
Chemotherapy for mesothelioma is not yet standardized for testicular mesothelioma, but certain chemotherapy agents have been explored in clinical cases. Drugs such as cisplatin and pemetrexed are FDA-approved for pleural mesothelioma, which forms in the lining of the lungs. These chemotherapy drugs are promising for other mesothelioma types.
A report published in Molecular and Clinical Oncology detailed a case of using cisplatin and pemetrexed to treat testicular mesothelioma. Chemotherapy was administered once every 28 days for six cycles. The patient showed promising results, remaining stable with no signs of recurrence or metastasis for six months post-treatment. Encouragingly, the patient remained free of local recurrence or distant metastasis for 3 years following the chemotherapy regimen.
While chemotherapy can treat testicular mesothelioma in some cases, the rarity of the disease means that data is limited. Research is ongoing, and more clinical trials are needed to better understand chemotherapy for this cancer.
Immunotherapy for Testicular Mesothelioma
Immunotherapy is becoming an important treatment for most types of cancer, including types of mesothelioma. However, its use for testicular mesothelioma is untested due to the rarity of this cancer.
Immunotherapy presents several potential advantages compared to chemotherapy and radiation. One of the primary benefits is immunotherapy’s ability to stimulate the body’s immune system to recognize and attack cancer cells.
This approach teams with the body to fight cancer and can avoid damaging healthy cells and organs. This can be a side effect of chemotherapy and radiation, which sends toxins or laser beams into the body to damage cancer cells.
Checkpoint Inhibitors for Testicular Mesothelioma
Checkpoint inhibitors, a class of immunotherapy drugs, are popular for treating other types of mesothelioma. Checkpoint inhibitors block specific proteins that prevent immune cells from attacking cancer cells.
The U.S. Food and Drug Administration (FDA) has approved Opdivo (nivolumab) and Yervoy (ipilimumab), both checkpoint inhibitors, for the treatment of pleural mesothelioma. The FDA also approved Keytruda (pembrolizumab) for pleural mesothelioma.
There are no studies of these immunotherapies for testicular mesothelioma, but their success in other types of mesothelioma offers hope. Clinical trials and further research are needed.
Radiation Therapy for Testicular Mesothelioma
Radiation therapy is not commonly used for testicular mesothelioma. One of the primary challenges is potentially damaging surrounding healthy tissues and vital organs.
The testes are located near sensitive structures, such as the bladder, bowel, and other organs. It’s challenging to use radiation without affecting these areas. Doctors must weigh the benefits against the potential harm.
Radiation therapy can be considered on a case-by-case basis, particularly in cases when other treatment options did not work. Further clinical trials are needed.
Multimodal Treatment for Testicular Mesothelioma
Specialists prefer a multimodal approach for the treatment of mesothelioma. This means combining different therapies to achieve the most effective outcomes. The most common combination is surgery and chemotherapy. Surgery removes most tumors while chemotherapy can kill any remaining cells and microscopic tumors. Immunotherapy can be paired with chemotherapy.
Testicular mesothelioma is so rare that data is limited on using multimodal treatment plans and combinations.
Palliative Care for Testicular Mesothelioma
In cases where treatment options do not work or are not options – due to how advanced the cancer is or the patient’s health – palliative care becomes crucial for testicular mesothelioma. Palliative care focuses on alleviating symptoms such as pain and swelling.
This type of treatment also can improve the patient’s quality of life. It may involve pain management through medications, support for emotional well-being, and controlling symptoms.
Testicular Mesothelioma Prognosis and Survival Rates
The prognosis and survival rates for testicular mesothelioma are difficult to measure due to the rarity of the disease. The limited number of cases makes building a large enough sample size for an accurate prognosis more challenging.
A study published in the Singapore Medical Journal reported a 2-year survival rate following the time of diagnosis of approximately 46%. A study at the University of Maryland Medical Center reported a median survival of 23 months. Some patients in this study survived for more than five years after the time of their diagnosis.
Several factors influence survival, with early diagnosis and treatment being critical. A study published in BMC Cancer reported that patients diagnosed in early stages – stage 1 and stage 2 – were more likely to have successful surgery followed by chemotherapy. These patients had significantly better survival rates than those in stage 3 and stage 4 who were less likely to have successful surgery.
Help for People Affected by Testicular Mesothelioma
If you or someone you know has testicular mesothelioma cancer, we recommend visiting a cancer center and working with an experienced medical team. This will provide you or a loved one with the best treatment options and other resources.
The first step is contacting a patient advocacy group, such as Mesothelioma Guide, to learn your options and how to contact these mesothelioma specialist teams. Email Karen Ritter at karen@mesotheliomaguide.com for quick assistance.
Sources & Author
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- The testicles. Canadian Cancer Society. Retrieved from: https://www.cancer.ca/en/cancer-information/cancer-type/testicular/testicular-cancer/the-testicles/?region=on. Accessed: 07/15/2020.
- Malignant Mesothelioma of the Tunica Vaginalis Testis. University of Maryland Medical Center. Retrieved from: https://meridian.allenpress.com/aplm/article/136/1/113/65053/Malignant-Mesothelioma-of-the-Tunica-Vaginalis?searchresult=1. Accessed: 10/02/2023.
- Two Case Reports of Benign Testicular Mesothelioma and Review of the Literature. Hindawi. Retrieved from: https://www.hindawi.com/journals/crionm/2017/5419635/. Accessed: 07/15/2020.
- Malignant mesothelioma of the tunica vaginalis testis: A case report and literature review. Molecular and Clinical Oncology. Retrieved from: https://www.spandidos-publications.com/10.3892/mco.2017.1450. Accessed: 07/15/2020.
- Signs and Symptoms of Mesothelioma. Moffitt Cancer Center. Retrieved from: https://moffitt.org/cancers/mesothelioma/symptoms/. Accessed: 07/15/2020.
- Malignant Mesothelioma of the Testes with Retroperitoneal Recurrence and Resection in an 80-Year-Old Male and Review of the Literature. Case Reports in Oncology. Retrieved from: https://pubmed.ncbi.nlm.nih.gov/37933307/. Accessed: 11/13/2023.
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- A rare malignant mesothelioma of the tunica vaginalis testis: A case report. Oncology Letters. https://www.spandidos-publications.com/10.3892/ol.2024.14305. Accessed: 06/02/2025.
- Malignant Mesothelioma of Tunica Vaginalis Testis: Update for 2022. Advances in Anatomic Pathology. Retrieved from: https://pubmed.ncbi.nlm.nih.gov/36129341/. Accessed: 06/02/2025.
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