Neuroblastoma
Neuroblastoma is a cancerous tumor that begins in nerve tissue of infants and very young children. Neuroblastoma is rare in children older than 10 years of age, however, it does occur occasionally in adults.
The tumor usually begins in the tissues of the adrenal gland found in the abdomen, but may also begin in nerve tissue in the neck, chest, and/or pelvis. The adrenal glands are positioned one on top of each of the kidneys. These glands secrete hormones and other important substances that are required for normal functions in the body such as the nervous system.
Most children affected by neuroblastoma have been diagnosed before the age of 5. In rare cases, neuroblastoma can be detected before birth by a fetal ultrasound.
In the US, approximately 500 children are diagnosed with neuroblastoma each year. It is the most common tumor found in children younger than 1 year of age. For unknown reasons, it occurs slightly more often in males than in females.
Neuroblastoma cancer cells can spread (metastasize) quickly to other areas of the body (i.e., lymph nodes, liver, lungs, bones, central nervous system, and bone marrow). Approximately 70 percent of all children diagnosed with neuroblastoma will have some metastatic disease.
What causes neuroblastoma?
A variety of chromosome abnormalities may present in neuroblastoma. Most neuroblastoma cells have genetic abnormalities involving chromosome #1, where a deletion or rearrangement is found on the short arm of this chromosome. The chromosome abnormality, in turn, causes amplification of an oncogene called MYCN. The amplification of MYCN causes uncontrolled cell growth. A variety of other chromosome abnormalities may also be present in neuroblastoma.
It is estimated that many neuroblastoma cases result from an inherited mutation, followed by a second mutation occurring after birth, which together initiate uncontrolled cell growth. The remainder of the cases occur from two acquired mutations after birth.
Neuroblastoma is more common in children born with fetal hydantoin syndrome, neurofibromatosis, and Beckwith-Wiedemann syndrome. The exact relationship between these conditions and the disease are not known.
The chance for neuroblastoma to be present in a future sibling of a patient is about 1 percent. If more than one child has neuroblastoma, the chance for reoccurrence increases.
Research is being conducted to determine if maternal exposure to any toxic substances, environmental pollutions, or radiation during pregnancy could have any link to the child developing neuroblastoma.
What are the symptoms of neuroblastoma?
The following are the most common symptoms of neuroblastoma. However, each child may experience symptoms differently. The symptoms of neuroblastoma vary greatly depending on size, location, and spread of the tumor. Symptoms may include:
- Abdominal mass, either felt during an examination or seen as a swollen abdomen
- Tumors in the face or head can cause swelling and bruising of the area around the eyes, uncontrolled eye movement, unsteadiness.
- Compression of kidney or bladder by the tumor may cause changes in urination
- Bone marrow involvement may present as pain, limping, paralysis, or weakness
- Diarrhea may be present; diarrhea is caused by a substance produced by the tumor (vasoactive intestinal peptide, or VIP)
- Fever
- High blood pressure and increased heart rate may occur depending on location of tumor and the organs the tumor compresses
The symptoms of neuroblastoma may resemble other conditions or medical problems.