These tumors develop from very primitive cells that usually mature into ova (eggs) in the ovaries of women and sperm in the testicles of men. About 90 per cent of all germ cell tumors occur in the ovaries and testes. They are known as gonadal tumors. The remaining 10 per cent appear outside of the gonads. They are known as extragonadal tumors. Extragonadal germ cell tumors normally develop in the chest, lower back and head.
Many scientists are convinced that extragonadal germ cell tumors can be associated with developmental problems that take place before birth. In the growing embryo, germ cells usually move from a site close to the middle of the body to their permanent home in the ovaries or testes. In some cases, though, there is a problem, and the germ cells do not reach their final destination. As an alternative, the misplaced germ cells stay in the mid-chest area between the lungs, in the lower back just above the buttocks or in the head near the pea-sized pineal gland situated in the middle of the brain. While misplaced germ cells develop in these sites, it sometimes happens that they appear into tumors, which may be either noncancerous (benign) or cancerous (malignant).
Extragonadal germ cell tumors represent 2 per cent to 3 per cent of all cancers occurring in the childhood. In very young children, these tumors usually develop in the lower back. The majority of these tumors are not cancerous. In adults, extragonadal germ cell tumors usually develop in the mid-chest area. Four out of ten of these tumors are cancerous. Cancerous extragonadal germ cell tumors occur very seldom. Only one new case is diagnosed every year for every 2 million to 3 million citizens of the United States. Cancerous extragonadal germ cell tumors appear equally in young boys and girls. In adults, however, they are nine times more frequent in men than in women.
There are several kinds of cancerous extragonadal germ cell tumors. At first, they are classified as seminomas or nonseminomas. Nonseminomas may be later classified as: embryonal carcinomas, malignant teratomas, endodermal sinus tumors, choriocarcinomas or mixed germ cell tumors. The specific kind of germ cell tumor influences both treatment and prognosis.
Symptoms of Extragonadal Germ Cell Tumor
Symptoms are dependent on the position of the tumor:
* Mid-chest area (mediastinum) — Cancerous germ cell tumors may result in chest pain, problems with breathing, cough or fever. Most frequently, they are recognized in men between 20 and 30 years of age.
* Lower-back area (presacral area) — A cancerous germ cell tumor normally occurs as a mass in the lower abdomen or buttocks of an infant or young child. Due to its size and position, the mass can lead to difficulty in walking, urinating or having a bowel movement. Noncancerous and cancerous germ cell tumors are much more widespread in children than in adult patients. In children younger than half a year the tumors are noncancerous in 98 per cent of cases. In children older than half a year, though, the tumors are cancerous in about 65 per cent of cases.
* Head (pineal area) — Cancerous germ cell tumors produce symptoms by means of pressing directly on parts of the brain or through interfering with the usual flow of the fluid circulating around the brain and spinal cord. The most common symptoms include: headaches, nausea, vomiting, memory loss, lethargy, difficulty walking, inability to look upward, uncontrolled eye movements or double vision. A child experiencing a tumor that starts to produce hormones may demonstrate physical signs of puberty at an abnormally young age. Nearly all pineal germ cell tumors develop in people over forty years of age.
Diagnosis
Due to the fact that cancerous extragonadal germ cell tumors occur very seldom, your healthcare provider will probably ask you about common medical conditions that could be producing your symptoms. For instance, if you have a cough, fever and problems with breathing, your physician may suspect a respiratory-tract infection. The real cause of your problems may be unknown until your physician recommends X-rays or scans of the area of the body where you are experiencing these symptoms.
Your healthcare provider will carefully examine you, paying particular attention to the area where you experience the symptoms. If you observe symptoms of a lower-back tumor, the examination may include a rectal examination and, in women, a pelvic examination. If you experience the symptoms of a pineal tumor, the physical examination will comprise a neurological examination as well.
Your healthcare provider will recommend various diagnostic tests depending on where the tumor is situated:
* Mid-chest area (mediastinum) — A typical chest X-ray demonstrates the tumor’s position in 95 per cent of cases. Computed tomography (CT) of the chest may show the extent of the tumor. CT of the abdomen may allow to see whether the tumor has extended to the liver or other areas. To acknowledge the diagnosis, physicians normally examine a piece of the tumor, that is removed with a needle (aspiration) or by cutting open the tumor. This procedure is called a biopsy. Nevertheless, some patients suffering from nonseminomas may be diagnosed by blood tests that search for abnormal blood levels of alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (beta-hCG).
* Lower-back area (presacral area) — Ultrasound or magnetic resonance imaging (MRI) are going to be applied in order to evaluate the size of the tumor. To check for tumor cells that have spread, your healthcare provider will probably recommend a bone scan, chest X-ray, CT scan of the lungs and a bone-marrow biopsy or aspirate. A biopsy of the tumor acknowledges the diagnosis.
* Head (pineal area) — even though a CT scan of the head will normally demonstrate a pineal tumor, an MRI gives more information. To provide the best diagnosis, the tumor is removed through the surgery and analyzed in a laboratory.
In the majority of patients with suspected germ cell tumors, blood tests of the levels of AFP and beta-hCG may help to determine the specific kind of tumor (seminoma or nonseminoma). In patients who have developed pineal tumors, AFP and beta-hCG levels may also be measured in the spinal fluid. The fluid is removed from the spinal cord for examining in a procedure called a spinal tap or lumbar puncture.
Expected Duration
If not treated, a cancerous extragonadal germ-cell tumor will keep on developing. Depending on its position, this cancer may finally extend to the lungs, bones (particularly the spine), liver or other areas.
Prevention
Unfortunately, there is no way to prevent cancerous extragonadal germ cell tumors.
Treatment Available
Treatment is dependent on the position and the kind of tumor. Generally, small seminomas are treated with radiation and larger seminomas are treated with chemotherapy followed by radiation. Non-seminomatous tumors in almost all cases are treated with chemotherapy followed by surgical removal of any larger tumors remaining after chemotherapy.
* Mid-chest area (mediastinum) — Seminomas are normally treated with high-dose radiation and in some cases with chemotherapy. Nonseminomas are usually treated with chemotherapy.
* Lower-back area (presacral area) — Chemotherapy is used to reduce the size of the tumor as much as possible before the surgery that aims at removing it completely. If the whole tumor is not removed in the course of surgery, a second course of chemotherapy may be applied, and then a second surgery to remove the remaining tumor.
* Head (pineal area) — The tumor is removed during a surgery. Both non-seminomas and seminomas can be treated with radiation. Nevertheless, due to the fact that high-dose radiation may damage parts of the brain, some hospitals try a combination of chemotherapy and a lower dose of radiation, particularly in case of non-seminomas.
Due to the fact that physicians are always eager to determine the best treatment for rare kinds of cancer, your healthcare provider may talk to you about the option of enrolling in a clinical trial. This is an experimental treatment program.
When To Contact a Specialist
Notify your physician whenever you or someone in your family observes any symptoms of a cancerous extragonadal germ cell tumor.
Prognosis
Noncancerous tumors located outside the brain very seldom pose any danger to survival. Survival rate for patients with cancerous tumors is dependent on the location of the tumor:
* Mid-chest area (mediastinum) — For seminomas, long-term survival is approximately 80 per cent in patients treated with radiation only. Some research proves that survival may rise when chemotherapy is also applied. For nonseminomas, long-term survival is roughly 75 per cent after chemotherapy.
* Lower-back area (presacral area) — Even for people with localized cancer, the survival rate is only about 28 per cent. It declines to 4 per cent for patients with disease that has extended to other organs.
* Head (pineal area) — After treatment, long-term survival is over 80 per cent.
