Yolk Sac Tumors

Rare germ cell tumors that often affect testicles and ovaries, causing cancer, are called yolk sac tumors (also known as endodermal sinus tumors). This type of cancer often occurs in children and sometimes may grow outside the reproductive system. For example, in the brain, chest, or abdomen. Healthcare professionals usually treat this cancer type with surgery and chemotherapy.

These are highly aggressive tumors that begin to develop in the ovaries or testicles. While the condition happens rarely, it is considered the most common type of cancerous germ cell tumor that is diagnosed in children. However, with early diagnosis and treatment, this cancer can be slowed, and the cancer can be prevented. This type of cancer is curable in the early stages, like other types of cancer. Immediate treatment is required because these tumors grow and spread quite fast.

Yolk Sac Tumors Types

These include:

Testicular yolk sac tumors – This is a type of testicular cancer that often affects children under 3 years old and people between their 20s and 30s. Commonly, yolk sac tumors are found before they spread. In such cases, this type of cancer is curable.
Ovarian yolk sac tumors – This type of cancer is more aggressive, and it often affects people 20 years old or younger. Approximately 30% of diagnoses involve children.

Yolk sac tumors, as well as other types of germ cell tumors, may appear in other parts of the body, including the chest, abdomen, brain, or tailbone. In such cases, the disease is called extragonadal germ cell tumors.

Symptoms

The symptoms usually appear differently among people with yolk sac tumors because they depend on where they appear. Check below some symptoms of this type of cancer:

A painless and firm lump in a testicle
Changes in bowel habits
Abdominal (belly) or back pain
Vision problems
Headaches
Shortness of breath
Cough
Irregular or heavy menstrual periods
Swelling in the abdomen or other parts of the body

If you or your child experiences any of the symptoms listed above, immediately contact a healthcare provider.

Causes

Healthcare providers do not fully understand why this type of cancer appears. However, like other cancers, the tumors begin to develop when specific cells develop DNA mutations (changes). In normal circumstances, DNA contains instructions that tell cells when to grow, multiply, and die. However, mutated DNA gives cells different instructions that make them grow and multiply abnormally. When abnormal cells become too many, they can form a mass called a tumor. Without immediate treatment, this cancer can spread throughout the body quite fast.

However, researchers continue to study these processes to understand why exactly cause these changes.

Risk Factors

While physicians do not know the exact cause of this cancer, they have identified some factors that may elevate your risk of developing it. Check some examples below:

Maternal age – According to some studies, older maternal ages are associated with an increased risk of yolk sac tumors.
Smoking – If you smoke during pregnancy, it also may increase the risk of yolk sac tumors.
Perinatal factors – Certain factors, such as low birth weight, low gestational age, and others, can also increase the risk of this cancer.
Genetic factors – Some research showed that some genes (including hypermethylation of RUNX3 or overexpression of GATA-4) could play a role in yolk sac tumors.
Environmental exposures – Prolonged exposure to certain environmental factors, such as traffic pollution, pesticides, and others, is associated with an increased risk for germ cell tumors.
Cryptorchidism (also known as undescended testicles) – People who have an undescended testicle are also at higher risk of developing yolk sac tumors.
A family history of this cancer
Some genetic syndromes – There are some genetic disorders that are associated with an increased risk of developing yolk sac tumors. For example, Klinefelter syndrome, Swyer syndrome, and others.

What Are The Possible Complications of Yolk Sac Tumors?

People who develop yolk sac tumors may also experience some complications, especially if they do not get immediate treatment. These include:

Fast spread and metastasis – This type of cancer tends to grow very fast and spread to other tissues and structures in the body. These include the ovaries, lymph nodes, lungs, liver, brain, and bones.
Superior vena cava syndrome (SVCS) – In rare cases, these tumors may grow and put pressure on the superior vena cava and cause this condition. It often causes swelling in the neck, face, and chest, and shortness of breath (rarely).
Pleural effusion and ascites – Some people may develop these conditions when yolk sac tumors spread to other parts of the body.
Unusual weight loss
Constipation
Pain during sexual intercourse

This document does not contain a complete list of yolk sac tumor complications. Discuss with your healthcare professional about ways to reduce the risk or prevent complications of this cancer.

Diagnosis

First, physicians will perform a physical examination to check for abnormalities linked to the disease, including lumps or swelling in the belly or testicles. Thereafter, they may ask some questions about your symptoms and medical and family history to get more clues about the disease. Commonly, to confirm the condition and rule out others that cause similar symptoms, doctors perform the following tests. These include:

Blood tests – These tests are often done to check for alpha-fetoprotein (AFP). High levels of this protein indicate yolk sac tumors.
Imaging tests – The following tests are used to get detailed images of different parts of the body. These tests can identify the exact location and size of the tumor. Physicians usually perform CT (computerized tomography) scans or MRI (magnetic resonance imaging) scans.
Surgical excision – Your healthcare professional will remove a small sample of the tumor to test it in the laboratory for cancerous cells. Sometimes, this test is called a biopsy. However, this is the only sure way to confirm yolk sac tumors.

Additionally, once you are diagnosed with this type of cancer, doctors will perform additional imaging tests to determine the extent (stage) of the cancer. Generally, the stages of testicular yolk sac tumors range from stages 1 to 3. For example:

1 – The cancer is localized and has not spread to nearby tissues.
2 – In such cases, the cancer may spread to nearby lymph nodes.
3 – This is an end-stage of cancer in which it spreads throughout the body.

However, the ovarian yolk sac tumor is classified into 4 stages. For example:

1 – The cancer has not spread and is localized on one or both ovaries.
2 – The second stage of this cancer means the tumor has spread below the pelvic area.
3 – In such cases, the cancer has spread to lymph nodes in the abdominal area.
4 – The last stage of this type of cancer means the tumors break and spread throughout the body (metastatic yolk sac tumors).

Treatment

Usually, the primary treatment for people who develop yolk sac tumors is surgery to remove the tumor. These include orchiectomy (the removal of the affected testicle) or oophorectomy (the removal of the affected ovary). When cancer spreads, doctors may also remove nearby lymph nodes.

They may also recommend chemotherapy drugs that are often given to patients intravenously (IV). It involves strong medicines that help destroy cancer cells throughout the body. Sometimes, chemotherapy helps shrink large tumors before surgery.

BEP Chemotherapy

This treatment involves a combination of medicines used to destroy yolk sac tumors. These include Bleomycin sulfate, Etoposide phosphate, and Cisplatin. BEP chemotherapy is considered one of the most powerful treatments for yolk sac tumors.

Frequently Asked Questions

What is the prognosis for yolk sac tumors?

Generally, these tumors are life-threatening without treatment. The only way to cure this type of cancer is early diagnosis and proper treatment. However, the prognosis depends on the exact location and size of the tumors. For instance, reduced levels of alpha-fetoprotein before chemotherapy often indicate a better prognosis.

What is the survival rate for yolk sac tumors?

If you receive treatments such as surgery and BEP, they significantly increase your survival rate. For example, the survival rate of people with treated ovarian yolk sac tumors is about 91% and they were alive at least 5 years after diagnosis. This survival rate decreases if the cancer spreads to other parts of the body to approximately 75%. Talk with your physician for more details.

Is the yolk sac tumor aggressive?

Yes, this type of cancer is highly aggressive, which means it often grows and spreads quite fast. That’s why early detection and immediate treatment are essential. Ask your healthcare provider if you have additional questions.