Germ cell tumor
Germ cell tumors are characterized by growths that develop from a particular lineage of reproductive cells called germ cells. Germ cells convert to eggs in female reproductive organs and into sperm in male reproductive organs Occurrence of germ cell tumors is particularly high in testicles and ovaries.
The chance of germ cell tumors occurring in other organs of the body is very rare. These kinds of cases are termed extragonadal germ cell tumors.
Example: Belly, brain, and chest.
Statistics and Extent
Germ cell tumor is the most common solid tumor seen in young males, ranging from 15 to 40 years old. There are approximately 70,000 cases of germ cell tumors in the world, accounting for 1% of all male tumors.
However, the mortality rate stands at 13% since 9507 patients have passed away due to this disease.
15% of adult anterior mediastinal cancers are constituted by primary mediastinal GCT, which are responsible for 1-3% of all germ cell malignancies.
They are also increasingly seen in the adolescent and young adult age group; however, less than 2 percent are diagnosed before they reach 60 years.
Types
Germ cell tumors may be:
- Malignant : Cancerous
- Benign : Non-cancerous
Both of these kinds of tumors have the ability to grow larger and inherently proliferate, but only cancerous germ cell tumors can propagate to other parts of the body.
Metastasized cancer, that is cancer that has already spread to different parts of the body can damage our organs and is more difficult to treat.
Classification
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Teratomas: They can be mature or immature and involve tissues like teeth, hair, muscle, and bone. The most common type of ovarian germ cell tumor is mature teratomas (dermoid cysts). Immature teratomas are benign, cancerous and they spread fast.
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Yolk Sac tumors (endodermal sinus tumors): These tumors contain cells that are similar to those of a developing embryo. They are malignant and therefore, propagate to lymph nodes and other organs. They are most commonly diagnosed in children.
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Germinomas: These are cancerous tumors that mainly occur in the ovaries and testes. Along with that, they are also common in the central nervous system.
Terminology- **a)Dysgerminoma**= *in ovaries* **b) Seminoma**= *in testicles* -
Embryonal cell carcinoma: They are a type of rare, malignant germ cell tumor. They can occur both in pure form and along with another tumor type in mixed tumors.
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Polyembryomas: They contain parts similar to embryos. They are often mixed with other germ cell tumor types in mixed tumors. They’re rare and propagate fast.
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Choriocarcinomas: They are made from cells that constitute the placenta during pregnancy. The placenta is a disc that is embedded into the uterine wall and helps the mother share digested food and oxygen with the baby.
Choriocarcinoma is *rare, cancerous,* and mostly occurs in the uterus. Both the fetus and the parents can be affected by this tumor. -
Mixed germ cell tumors: They are a mix of two or more types of cancerous germ cell tumors.
Difference between seminomas and non-seminomas
Germ cell tumors in males are classified as
- Seminomas: They propagate and develop more slowly than non-seminomas
- Non-seminomas: They grow bigger and proliferate faster than seminomas. Yolk sac tumors, embryonal cell carcinomas, choriocarcinomas and teratomas are included in non-seminomas.
Both of these types are cancerous tumors that may affect testicles.
Location
Germ cell tumors originate from-
- testes
- ovaries
- chest- mediastinal tumor
- back of the- retroperitoneal tumor
- brain- pineal region tumor
- lower- sacrococcygeal tumor
Stages
Firstly, a doctor indicates the occurrence of a germ cell tumor. Consequently, they analyze the stage of the tumor to provide the appropriate treatment.
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Stage 1- The tumor in stage 1 has not spread to different parts of the body and is localized in its original area of development. In this case, surgery is appropriate.
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Stage 2- In stage 2, the tumor has started to spread to different parts of the body, to different tissues and structures, from the ovary and testes, but it is still contained in the pelvis region.
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Stage 3- As a germ cell tumor develops and grows to stage 3, the tumor usually has proliferated far from the gonad region and occurs with regional lymph nodes.
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Stage 4- It is the most dangerous and severe stage, where the germ cell tumor has already spread to the surrounding tissues and organs.
The most common sites are the liver, lungs, and distant lymph nodes.
Symptoms
People with germ cell tumors may have-
- A noticeable lump in the affected part
- Pain in the affected body part
- Abnormally shaped testicle
- Lump or swelling of the abdomen
- Constipation
- Cough
- Trouble breathing
- Headache
- Vomiting
Causes
The cause of germ cell tumors is not known. These tumors occur when there are changes in the DNA of these germ cells. The DNA gives alternative instructions to those considered normal. This causes the tumor to propagate at a faster rate than normal and healthy cells. The tumor cells develop a mass that presses on the surrounding tissues and organs.
These DNA changes can also cause the germ cells to convert to cancer cells, which destroy healthy body cells and proliferate to different parts of the body.
Risk Factors
A family history of germ cell tumors or a history of a few particular conditions makes a person more likely to get germ cell tumor. These include-
- Untreated, undescended testicles or cryptorchidism
- Turner Syndrome
- Klinefelter Syndrome
Prevention
There are no known prevention methods for germ cell tumors yet.
Diagnosis
Diagnosis can be done through imaging tests, blood tests, and surgery.
Imaging tests
The size and location of the tumor can be understood after taking pictures of the patient’s body using imaging tests. Ultrasounds are used to take images of ovaries and testicles. It also helps the doctor to know about the different types of lumps that have the possibility of being a germ cell tumor.
Other imaging tests:
-CT scan
-magnetic resonance imaging, also called MRI.
Blood tests
A blood test can find proteins made by cancer cells. This type of test is called a tumor marker test. Having these substances in the blood doesn't mean that someone has cancer. But if a level is higher than typical, that information can help the healthcare team better understand what's going on in the body.
Tumor marker tests help us identify the proteins that are made by different types of cancers. The presence of these proteins isn’t harmful or dangerous, but a level higher than normal values helps doctors understand the patient’s body better.
Surgery
Cancerous lumps are required to be removed by surgical interventions.
Then, the tissue is sent for lab testing, which helps us understand if it is cancer or not.
Treatment
Treatments→ surgery, chemotherapy, and radiation therapy
Surgery
Different types of surgical interventions are used to remove the tumor from the patient’s body, depending on the tumor’s localization. If the tumor is located in the testicle, then the entire testicle often has to be removed.
Chemotherapy
Strong chemotherapy medicines, usually in pill form, are given through the vein of a patient to treat cancer.
Radiation therapy
Powerful energy beams coming from X-rays and protons help to treat cancer through radiation therapy. It involves the use of a machine that directs radiation towards the patient’s body.
Side effects and Maintenance
- Secondary Malignant Neoplasms
- Cardiovascular diseases
- Pulmonary toxicity
- Nephrotoxicity
- Neurotoxicity
- Decreased Fertility
- Hypogonadism
- Psychosocial problems
The occurrence and length of these effects depend on treatment type and intensity
FAQs
Who gets germ cell tumors?
Only half of the childhood germ cell tumors are cancerous. Only 2-3 out of 1 million children every year have germ cell cancer.
What tests and procedures will my child need?
Symptoms vary based on the tumor’s size and location. For example:
- Tumor Biopsy
- Blood Tests
- MRI
- CAT scan
- Bone scan
- Chest X-ray
- Ultrasound
- Venus Access Device
What are the causes?
The causes are still unknown and being researched by doctors.
How long will my child’s therapy last?
Treatment is usually given over several months, along with follow-up checkups and blood tests. Specifications depend on the type and stage of the cancer.
Are Germ Cell Tumors Inherited?
They do not seem to be inherited since it is rare for more than one parent to have this disease.
What Are Metastases?
Metastases mean when the tumor spreads to different body organs and tissues away from the site of origin.
Citations and Sources
- Introduction- Mayo Clinic: Overview (https://www.mayoclinic.org/diseases-conditions/germ-cell-tumors/symptoms-causes/syc-20352493)
- Statistics and Extent- ScienceDirect: Abstract and Introduction (https://www.sciencedirect.com/topics/medicine-and-dentistry/germ-cell-cancer)
- Types- Cleveland Clinic: What are the types of germ cell tumor? (https://my.clevelandclinic.org/health/diseases/23505-germ-cell-tumor)
- Difference between seminomas and non-seminomas- Cleveland Clinic: Difference between seminomas and non-seminomas (https://my.clevelandclinic.org/health/diseases/23505-germ-cell-tumor)
- Location- Cancer Research UK: Where are germ cell tumors found?(https://www.cancerresearchuk.org/about-cancer/germ-cell-tumours)
- Stages- Shea | Global Patient Services: Germ Cell Tumor Staging (https://www.shebaonline.org/hemato-oncology/pediatric-germ-cell-tumors/)
- Symptoms- Yale Medicine: What are the symptoms of germ cell tumors? (https://www.yalemedicine.org/conditions/germ-cell-tumors)
- Causes- Mayo Clinic: Causes (https://www.mayoclinic.org/diseases-conditions/germ-cell-tumors/symptoms-causes/syc-20352493)
- Risk Factors- Cleveland Clinic: What are the risk factors associated with germ cell tumors? (https://my.clevelandclinic.org/health/diseases/23505-germ-cell-tumor)
- Diagnosis and Treatment- Mayo Clinic: Diagnosis and Treatment (https://www.mayoclinic.org/diseases-conditions/germ-cell-tumors/diagnosis-treatment/drc-20580169)
- Side Effects- National Library of Medicine: Abstract (https://pubmed.ncbi.nlm.nih.gov/23008318/)
- FAQs- Association for Pediatric Hematology/Oncology Nurses: Handbook for families (https://www.bcchildrens.ca/sites/g/files/qpdaav156/files/2024-12/germ-cell-tumours-handbook.pdf)