Seminomas are a rare type of cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs that develop from germ-cells. In most cases, they develop in the testicles, however they have been reported in other locations.
Germ cell tumours are a rare group of neoplasms that arise from primordial germ cellsa cell that develops into reproductive cells (eggs in females, sperm in males) – the cellsthe basic structural and functional unit of all living things responsible for developing into reproductive cells (gametes) such as ovum and sperm. These tumours typically originate in the gonads, which are the organs that produce gametes (ovaries in females and the testicles in males). These tumours are referred to as gonadal germ cell tumours. In some cases, germ cells can migrate to other parts of the body during early embryonic development, leading to tumoura tissue mass that forms from groups of unhealthy cells formation outside of the gonads later in life. These are known as extragonadal germ cell tumours, and are most commonly found in the brain, mediastinumthe space between the lungs that holds many important structures, including the heart, trachea and oesophagus, retroperitoneuma space located behind the abdomen that contains many important bodily structures, such as the kidneys, or sacrococcygeal region.
Ovarian dysgerminomas, seminomas, and germinomas share similar histological characteristics and are often considered to be the same tumour, with the name of the tumour varying according to anatomical location. When arising in the ovary, the tumour is termed a dysgerminoma; in the testis, it is called a seminoma; and when occurring at extragonadal sites – most commonly within the central nervous system – it is referred to as a germinoma.
Seminomas are generally diagnosed in males between the ages of 30-49. However, anyone can develop this disease.
Types of Seminomas
There are two primary types of seminomas, which are classified by their location.
Testicular Seminoma
Testicular seminomas are the most common type of seminoma, and are the most common type of testicular cancer. In general, testicular seminomas are diagnosed in males between the ages of 30-49, however, it can affect anyone with testicles – including men, teenagers, transgender women, non-binary individuals, and intersex people – at any age. Testicular seminomas are generally slow growing, rarely metastasise and can have a good prognosisto predict how a disease/condition may progress and what the outcome might be.
Mediastinal Seminoma
Mediastinal seminomas are a rare type of germ-cell tumour that develops in the mediastinum, most commonly the anterior mediastinum. It is most commonly found in males over 10 years old, with the average age of diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results being 40. Mediastinal seminomas are generally less aggressive than other types of germ-cell tumours, and can have a good prognosis when found early.
Treatment
If a seminoma is detected, it will be staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets, and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading help your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (nodea small lump or mass of tissue in your body) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissuea group of cells that work together to perform a function.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localisedaffecting only one area of body cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, age, stage of disease and overall health.
Treatment options for seminomas may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence, potentially including:
-
- Unilateral orchidectomyremoval of one testicle /orchiectomy.
-
- Bilateral orchidectomyremoval of both testicles /orchiectomy.
-
- Lymphadenectomysurgical removal of lymph node(s).
-
- Testicular prosthetic surgeryinsertion of a prosthetic testicle(s) after an orchidectomy.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Testicular Seminoma Treatment and Fertility
Treatment for testicular seminoma may make it difficult to conceive a child. If fertility is important to you, discuss your options with your doctor and a fertility specialist prior to the commencement of treatment.
Risk factors
While the cause of testicular seminomas remains unknown, the following factors may increase the likelihood of developing the disease:
- Cryptorchidism (undescended testicles).
- A personal history of testicular tumours.
- A family history of testicular germ-cell tumours.
- Testicular microlithiasis.
- Infections with human immunodeficiency virus (HIV), mumps or orchitis.
- A history of trauma.
- Organ transplanta surgical procedure that involves removing a failing or damaged organ and replacing it with a healthy one from a donor immunosuppression.
Because of how rare mediastinal seminomas are, there has been limited research done into the riskthe possibility that something bad will happen factors of this disease. However, a potential link to a genetic abnormality on chromosome 12 known as isochromosome 12p has been identified.
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Symptoms
The symptoms of seminomas will often vary based on location.
Symptoms of Testicular Seminoma
Symptoms of testicular seminomas may include:
- A painless testicular massa growth of cells that come together to make a lump, may or may not be cancer.
- Testicular discomfort.
- Aches in the lower abdomenstomach, stomach area, belly, testicle(s) and/or scrotum.
- An abdominal mass.
- Back pain.
Symptoms of Mediastinal Seminoma
Symptoms of mediastinal seminomas may include:
- Dyspneadifficulty breathing, shortness of breath.
- Chest pain.
- Persistent cough.
- Weight loss.
- Fevers.
- Haemoptysiscoughing up blood.
- Superior vena cava syndrome, which has its own set of symptoms:
- Coughing.
- Dyspnea.
- Swelling of the face, neck, and/or upper arms.
- Gynecomastia (enlargement of breast tissue in males).
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have a seminoma, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imagingtests that create detailed images of areas inside the body tests, potentially including:
-
- Ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body .
-
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
-
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
-
- Chest X-raya type of medical imaging that uses x-ray beams to create detailed images of the body .
- Exploratory surgerya surgical procedure used for conditions that cannot be confirmed by scans and tests alone.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
Exploratory Surgery for Testicular Seminoma
After conducting the previously mentioned diagnostic tests, your doctor may strongly suspect that you have a testicular seminoma. In most cases, a diagnosis can be confirmed after a biopsy, where a section of tissue is removed and analysed for cancer cells. However, doctors avoid conducting a biopsy in patients who have suspected testicular cancer as there is a small risk that making an incision in the scrotum could cause cancer cells to spread. As such, the only way to confirm the diagnosis safely is to perform a unilateral orchidectomyremoval of one or both testicles, also known as orchiectomy.
Once the testicle has been removed, it will be sent to a laboratory and analysed for cancer cells.