Malignant germ cell tumor
Overview
Germ cell tumors develop from cells, called germ cells, that normally mature into eggs in the female ovaries and sperm in the male testes. About 90 percent of all germ cell tumors are gonadal, which means they develop within the ovaries and testes. The remaining 10 percent are extragonadal, which means they develop somewhere outside the gonads, usually the chest, lower back, and head. Germ cell tumors can be benign (noncancerous) or malignant (cancerous).
Symptoms
* Asymptomatic in early stages * Localized swelling * Constipation * Incontinence * Weak legs
Causes
Research has shown that extragonadal germ cells tumors are caused by problems that occur during fetal development. The germ cells normally move from the yolk sac into the embryo and grow within the developing testes, if the fetus is male, or the ovary, if the fetus is female. Sometimes, however, the germ cells don't migrate to the correct location and they multiply in locations where they shouldn't be. These are extragonadal germ cell tumors and they usually occur in the midchest area near the lungs (the mediastinum), just above the buttocks (the presacral area), or near the pineal gland, which is located around the middle of the brain. Gonadal germ cell tumors occur when the germ cells migrate to the correct location, but develop abnormally.
Diagnosis
To diagnose a germ cell tumor, your doctor will take a complete medical history and carefully examine your child. If the symptoms indicate the possibility of a tumor in the presacral region, he or she will carefully examine the rectal and pelvic area. If symptoms indicate a pineal germ cell tumor, the doctor will also perform a neurological exam. To make a definite diagnosis, he or she will order x-rays and diagnostic imaging scans. Tumors in the mediastinum are diagnosed with a chest x-ray and computed tomography (CT) scans of the chest and abdomen. A small sample of the tumor is removed either surgically, called an open biopsy, or using a needle, called a needle biopsy, to check whether the cells are benign or malignant. Biopsies are done under general or local anesthesia so your child does not feel any pain. Tumors in the presacral area are diagnosed with ultrasound or magnetic resonance imaging (MRI) of the area above the buttocks. A biopsy will show whether the tumor is benign or malignant. If the tumor is malignant, the doctor will also order a bone scan, chest x-ray, and lung scan to check whether the cancer has spread, called metastasis. Pineal tumors can be seen on a CT scan of the head or an MRI. For a definite diagnosis, the tumor is surgically removed. With most germ cell tumors, blood tests show high levels of alpha-fetoprotein (AFP), which is produced by the liver, and beta-human chorionic gonadotropin (beta-hCG), a hormone that is produced during pregnancy, but also occurs in people with certain types of cancer. These substances may also be found in the spinal fluid of patients with pineal tumors. Benign germ cell tumors are called teratomas, and are divided into mature teratomas, immature teratomas, and teratomas that include some malignant germ cell components. Cancers that contain malignant germ cell tumors include embryonal carcinoma, germinoma, choriocarcinoma, and endodermal sinus, or yolk sac, tumor.
Treatment
Treatment depends upon the type of germ cell tumor and its location. Malignant tumors must be treated or they will continue to grow. The first step in treatment is to surgically remove as much as the tumor as possible. Infants and children with benign germ cell tumors can usually be treated successfully with surgery and follow-up monitoring to ensure the tumor has not returned. Older children with malignant germ cell tumors, especially those in the presacral region above the buttocks, may first be treated with chemotherapy. Chemotherapy involves doses of very strong medicine that are often given first to control the growth of the tumor by killing the cancer cells. Then, the tumor is surgically removed. Your child will receive additional chemotherapy treatment after the surgery. Chemotherapy can make your child feel sick and weak, and lose his or her hair. These side effects are temporary and will go away once the chemotherapy treatments are finished. Your doctor can prescribe medicine to counteract these side effects if your child cannot tolerate them. Chemotherapy has also been used successfully in infants with endodermal sinus tumors. After treatment, your doctor will continue to monitor your child's alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (beta-hCG) levels to make sure the tumor has been completely removed. If your child has a rare type of malignant germ cell tumor, your doctor may discuss the possibility of clinical trials with you. These are experimental treatment programs. It is important to keep in mind that, today, malignant germ cell tumors in children have a higher cure rate than they did in the past.