What is Testicular Teratoma?
A testicular teratoma is a type of tumor that develops from cells that are meant to become sperm, and is made up of various body tissues. This type of tumor can develop from one or multiple layers of the germ cell (the stem cell that give rise to sperm), including the endoderm, mesoderm, and ectoderm.
According to categorization by the World Health Organization, testicular tumors are split into two broad groups. The first group includes tumors that start from abnormal germ cells, such as in seminomas and non-seminoma germ cell tumors (NSGCT), which include teratomas that occur after puberty, embryonal carcinoma, choriocarcinoma, and yolk sac tumors (YSTs). The second group includes those tumors which are not derived from germ cells, including some types of yolk sac tumors, teratomas that occur before puberty, and spermatocytic tumors.
Most teratomas in adult men are a type of cancerous germ cell tumor. Teratomas make up about 3 to 7% of NSGCTs and about half of mixed germ cell tumors. The World Health Organization identifies two types of testicular teratomas:
The prepubertal teratoma is generally slow-growing and does not start from abnormal germ cells. These tumors do not tend to spread to other parts of the body and the testicles show normal sperm production. These kinds of tumors can also be found in adult patients and include dermoid or epidermoid cysts.
The postpubertal teratoma, on the other hand, starts from abnormal germ cells and can spread to other parts of the body, which occurs in about 22% to 37% of cases.
There’s a rare type of teratoma which transforms into another kind of tumor that resembles a different type of body cell cancer. This tumor has a unique prognosis and treatment, and it’s important to distinguish it from postpubertal teratomas.
Patients with localized disease generally have good outcomes and are usually treated with surgery. However, patients with disease that has spread to other parts of the body generally have worse outcomes, with treatment depending on various clinical and pathological factors. These patients often rest on a team of different healthcare professionals.for treatment. Tumors that have spread do not respond well to chemotherapy, so the goal is usually to remove all of the tumor with surgery.
What Causes Testicular Teratoma?
The World Health Organization (WHO) has classified a kind of tumor called teratoma into two types, based on if they appear before puberty, known as prepubertal, or after puberty, known as postpubertal. The postpubertal type of teratoma can evolve from other types of germ cell tumors, and could possibly spread to other parts of the body in a similar manner to the original tumor or other germ cell tumors.
Germ cell tumors begin from primitive cells that can turn into different cell layers and create various types of body tissue. This mixture of different types of tissue characterizes a teratoma. It’s common to find an abundant amount of the 12th chromosome and the presence of a protein called IMP3 in these types of tumors.
There are also known risk factors for developing germ cell tumors. These include being smaller than average at birth, undescended testes (cryptorchidism), a birth defect of the penis (hypospadias), maternal bleeding during pregnancy, older maternal age, newborn jaundice, and a retained placenta after birth.
Cryptorchidism, or undescended testes, is strongly linked with a 3-5 times higher risk of these tumors, and some studies even suggest the risk could be as high as 8 times. Men who struggle with fertility are also at a greater risk of testicular cancer. Whether certain factors before birth influence this risk is still debated and no international agreement has been reached. It has been suggested that exposure to synthetic estrogen during pregnancy could be linked to cryptorchidism and thus, a higher risk of testicular cancer. Furthermore, children whose mothers smoked during pregnancy had a slightly higher risk of undescended testes.
A person’s past medical history can play a role too. If a person has previously had a germ cell tumor in one testis, they are at higher risk for developing a tumor in the other testis in the future. Receiving radiation therapy to the pelvic area is also a significant risk factor for developing a testicular tumor.
Finally, a family history of testicular cancer can increase the risk of getting a similar tumor, with the risk being four times higher for brothers. However, the US Preventive Services Task Force advises against screening for this, given their Grade D recommendation, which means that there is moderate or high certainty that the screening has no net benefit or that the harms outweigh the benefits.
Risk Factors and Frequency for Testicular Teratoma
Testicular cancer is most frequently seen in individuals aged between 20 to 35 years, making it the most common solid tumor within this age group. The vast majority of these cancers are testicular germ cell tumors (GCTs), which account for about 95% of all testicular cancers. The most common type of GCT is seminoma, but other types such as embryonal carcinoma, choriocarcinoma, yolk sac tumor, and teratoma also exist. These are less common, tend to be more aggressive, and can occur in pure or mixed forms.
Testicular teratoma is an occurrence in both children and young adults, with 20 to 35 years being the most commonly affected age group. In children, it typically presents within the first 2 years of life and, after the yolk sac tumor, is the second most common GCT type. Amongst young adults, pure forms are rare, but mixed forms with other GCT types are more common.
When it comes to testicular cancer overall, about 90% of cases present with the disease in the local or regional stages. Testicular cancer, as a rule, has a high cure rate, with 95% of patients surviving for at least 5 years after diagnosis. However, survival rates can vary based on the specific type of tumor. For instance, the presence of teratoma is associated with higher disease-related death rates and higher rates of spreading to other parts of the body and resistance to treatment. Still, it was found that 92% of deaths were linked to non-teratomatous GCT metastases that were chemoresistant.
Signs and Symptoms of Testicular Teratoma
If someone is experiencing a lump in the testicle or pain near their groin, they should get it checked by a doctor. Testicular cancer is a worry, especially for younger men and those concerned about their ability to have children. Some critical bits of information for the doctor could include cases of non-descended testes, past instances of twisted testes, any injury to the groin area, how quickly the present lump has grown, and any other related symptoms. It’s important to mention if someone had surgery for a non-descended testis because there’s a higher risk of cancer in these cases compared to a regular testis. Patients may not have any symptoms or could notice a painless swelling in the testicle. In other cases, they might have painful swelling, often from bleeding and blood clot formation inside the tumour or twisted testes.
The doctor should carry out a thorough physical examination, along with an ultrasound scan and relevant blood tests. Though it’s rare, there could be tumors in both testes, so it’s necessary to compare them. If one side of the scrotum appears empty without the usual wrinkles, it could indicate a non-descended testis. Swelling in the groin could suggest that a non-descended testis has turned cancerous. An important thing to note is that rapidly growing testicular cancer might feel soft because of an additional fluid-filled sack around it. But often, the solid lump can be felt if carefully examined. In more advanced cases, the cancer could cover the testes and thicken the cord-like structures within them. Despite this, the skin of the scrotum usually remains unaffected until the disease is in a very late stage. In some cases, the lymph nodes in the stomach area might be enlarged and can be felt in those who are slender. In serious cases, the left-hand side lymph nodes near the collarbone (otherwise known as Virchow’s nodes) could also be more prominent.
Testing for Testicular Teratoma
To diagnose and understand the stage of your disease, your doctor might use a combination of lab tests and imaging techniques. These can include blood tests, abdominal scans, chest X-rays, CT scans, and in certain cases, an MRI or PET scan.
Blood tests can measure specific tumor markers which can make it easier for the doctor to tell if you might have a germ cell tumor. If the blood tests show higher levels of the molecules hCG and AFP, this might suggest the tumor could be a mixture of a yolk sac tumor and cells which secrete hCG.
Ultrasound is the best initial imaging technique for examining potential issues with the testicles. It provides a non-invasive way to spot scrotal masses and can tell the difference between issues inside the testicles and those in surrounding areas, with almost 99% accuracy. It can also compare the affected testicle to the healthy one, making it easier to spot any abnormalities.
The texture of a normal testicle should appear evenly granulated and positioned beneath the epididymis, which may look similar or brighter on ultrasound images. A condition called a hydrocele, which is a buildup of fluid around the testicle, shows up as extra fluid around the testicle that can be easily distinguished from cystic masses.
On ultrasound, any solid mass found within the testicles is generally assumed to be malignant, or cancerous unless tests prove otherwise. The look of the mass on ultrasound can provide useful information about its makeup, and testicular tumors usually look less bright than normal tissue (hypoechoic). They could be varied if they contain calcifications and cysts. A solid or primarily cystic mass might suggest a testicular teratoma, a type of germ cell tumor. The presence of calcification, or hardened tissue, within the tumor could also indicate a teratoma. The blood flow to and from the tumor can be assessed with a Doppler scan, which measures the flow of blood through your vessels.
Regarding MRI scans, these are generally only used in the typical clinical setting when cases are more complex. MRIs primarily help to better analyze masses outside the testicles.
A PET scan, on the other hand, rarely aids in distinguishing between different types of tumors because teratomas typically lack the usual high glucose uptake seen in other tumor tissues. Therefore, PET scans are not useful in distinguishing between teratomas and necrotic, or dead tissue.
Treatment Options for Testicular Teratoma
The International Germ Cell Consensus Classification looked at more than 5000 cases of a type of cancer called non-seminomatous Germ Cell Tumors (GCTs) which had spread within the body. These cases were treated with a type of chemotherapy called cisplatin and were monitored for 5 years. They created a system to evaluate the risk of the patient based on several factors including the type of cancer, location of the primary tumor, levels of certain biomarkers, and spread of the cancer to organs other than lungs. Depending on these risk factors, the likelihood of the patient’s death varied between 10% to 60%.
If a patient has a mass in the testicle along with signs of cancer, the standard treatment is orchiectomy, a surgery to remove the affected testicle. It’s also an option to put a prosthetic (artificial) testicle in place during surgery for cosmetic purposes. If the mass doesn’t look like its spread within the testicle and doesn’t appear to come from germ cells (cells that give rise to sperm), the patient might be a candidate for testis-sparing surgery. However, if germ cell neoplasia in situ (an early stage of a germ cell tumor) is suspected, the entire testis should be removed because there is a risk of it developing into a more aggressive tumor. The type of treatment after the removal of the testicle depends on various factors such as the type of cancer, whether it has spread to blood vessels or lymph nodes, and results of a CT-scan.
For stage I tumors, where the cancer is limited to the testicle and hasn’t spread to lymph nodes or other parts of the body, treatment varies depending on whether the cancer has spread to blood vessels and the scrotum, and on biomarker levels in the blood. Orchiectomy is the first choice of treatment, and this may be followed by surveillance (monitoring for any signs of cancer recurrence) or removal of lymph nodes in the retroperitoneum (the space in the abdominal cavity behind the intestines). This lymph node removal may be chosen in certain circumstances such as in the presence of teratoma (a type of germ cell tumor) or when a CT scan can’t rule out lymph node involvement. If the patient opts for surveillance instead of lymph node removal, it’s important that they stick to a strict follow-up schedule to detect any signs of cancer spread quickly. Alternatively, if the patient opts for preventive chemotherapy, a single cycle of a trio of drugs (bleomycin, etoposide, and cisplatin) is usually recommended.
People with stage II tumors have cancer that has spread to the lymph nodes in the retroperitoneum but nowhere else. Depending on the size of the lymph nodes and levels of biomarkers in the blood, these patients are typically treated with chemotherapy. If there’s tumor left behind after surgery (residual masses), the patient should go through another surgery to remove the remaining cancer. If the cancer has spread to the wall of a large vein in the abdomen (inferior vena cava) or formed blood clots, these areas should also be completely removed. This resection needs to be as thorough as possible as the residual tumors can locally grow, transform into more aggressive cancer forms, and relapse. Also, these residual masses tend not to respond to chemotherapy and can worsen despite it.
What else can Testicular Teratoma be?
When looking at a case of testicular teratoma, it’s crucial to consider that the symptoms might be caused by other conditions. Here are a few other issues that might look similar:
- Other types of testicular germ cell tumors
- Epidermoid cyst (a type of benign growth)
- Metastases, which are when cancer cells from another tumor spread to the testicles
- Lymphoma, a type of cancer that starts in cells that are part of the body’s immune system
- Testicular torsion, a painful condition caused by the twisting of the testicles
- Inguinal hernia, a condition when some of your intestine or fat pushes through a weak spot in your lower belly and into your groin
- Testicular abscess, a pocket of pus that forms due to an infection
What to expect with Testicular Teratoma
The International Germ Cell Cancer Collaborative Group (IGCCCG) is a system used for assessing how advanced a certain type of cancer known as non-seminomatous germ-cell tumors are in patients. The system identifies three risk classes:
1. Good: This refers to patients with tumors originating in the testicles and without serious spread to other areas of the body, alongside specific blood levels of certain chemicals.
2. Intermediate: This includes patients similar to the ‘Good’ category but with slightly higher chemical levels in their blood.
3. Poor: Patients in this category either have tumors that began in the chest region or serious spread, or their blood chemical levels are much higher.
After puberty, a certain type of tumor known as a teratoma tends to be more dangerous. Adult patients with a specific kind of teratoma often see it spread to other parts of the body (about 40% of the time); however, when this happens and the spread is contained within a particular region, about 100% of these patients survive for at least 5 years.
When these teratomas transform into a different kind of cancer, affected patients often don’t respond well to the usual treatment for germ cell tumors used when cancer spreads. As a result, their chances for survival reduce.
Although mature teratomas are usually somewhat predictable, in some cases they can become aggressive and transform into other forms of cancer like sarcomas or carcinomas (types of tissue and skin cancers). When this occurs, the risk of a disease-related death becomes higher.
Possible Complications When Diagnosed with Testicular Teratoma
Having an orchiectomy combined with lymph node removal can often lead to serious side effects such as ejaculating in the reverse direction. Therefore, doctors recommend a type of surgery that saves the nerves, whenever it is appropriate (in stage one of the disease with normal serum markers).
Possible complications following the procedure:
- Ejaculating in the reverse direction after surgery.
Preventing Testicular Teratoma
The US Preventive Services Task Force advises against regular screenings for testicular cancer across the general population. However, those who are at a particularly high risk for this type of cancer need to be recognized and informed about their specific risk. It’s important for these high-risk individuals to be aware of the most usual signs and symptoms of a form of testicular cancer known as a testicular teratoma.
Even though there isn’t any specific suggestion for regular self-examinations, it is possible for high-risk individuals to learn how to conduct a basic physical check-up on themselves, getting in touch with a healthcare professional if they notice anything unusual. This simple check could potentially make it easier to spot cancerous growths and reduce the need for ultrasound examinations, which are often used as an early detection method.
In the end, education and peace of mind are crucial for high-risk men and those already diagnosed with testicular cancer. By improving understanding and strengthening the relationship between patient and doctor, we can help to clear any hurdles that might hinder effective medical communication.
