Neuroblastoma is a type of pediatric cancer that occurs when neuroblasts fail to mature into functioning nerve cells, and instead become cancer cells that then cause a tumor to develop anywhere nerves are present. The mass that forms is most commonly seen in the nerve tissue of the adrenal glands, which rest atop the kidneys and generate hormones that manage the body's blood pressure, heart rate, and blood sugar. A hard lump may also be found in the abdomen, chest, neck, pelvis, and spine as well.
The location of a neuroblastoma tumor and whether it has metastasized will determine the type of symptoms, which can include loss of appetite, fatigue, joint pain, and fever. While some cases go away on their own, others will not and require multiple neuroblastoma treatments.
Most neuroblasts are able to mature completely within a typical gestational period, although a small number of immature neuroblasts may be present at birth. For most newborns with immature neuroblasts, the neuroblasts either mature or disappear. However, in the case of urological neuroblastoma, the underdeveloped cells multiply and form a tumor within the adrenal region. It is not completely clear why some neuroblasts develop into neuroblastoma and others don't, but recent research has found that a defect in the genes of a neuroblast can cause it to divide uncontrollably and act as a cancer cell. With Wilms Tumor (nephroblastoma), a condition similar to neuroblastoma, researchers believe that the kidney cells can develop errors in their DNA during a child's early development.
The signs and symptoms associated with neuroblastoma depend upon the area of the body affected. Urologically speaking, neuroblastomas in the abdomen can alter urinary habits if they press on the urinary tract. The signs include:
- Frequent urination (or overactive bladder)
- The inability to empty the bladder (urinary retention)
Additional symptoms associated with neuroblastomas found in the abdomen include:
- A tender lump under the skin
- A feeling of fullness in the abdomen
- Abdominal swelling and pain
- Swelling in the legs
When this type of cancer originates in or invades the chest, neck, pelvis, and spine, symptoms may include:
- curvature of the spine (scoliosis)
- Bone pain
- Unexplained weight loss
- Back pain
- Protruding eyes
- Swelling in the face
- Drooping eyelids
- Dark, bruise-like circles under the eyes
- Painless lumps under the skin
- Paralysis or instability
- Anemia (iron deficiency)
- Lack of appetite
- Swelling of the ankles, feet, scrotum, or legs
- Shortness of breath
- High blood pressure
- Muscle spasm
Stages of Neuroblastoma
When determining the extent of the cancer, a staging system is applied. The following stages include:
- Stage 1: The tumor is localized to the area where it originated, and is often only on one side of the body. Lymph nodes inside the tumor may have neuroblastoma cells, but lymph nodes outside the tumor are cancer free. Any and all detectable tumors can be removed with surgery.
- Stage 2A: This stage is very similar to stage 1, except not all visible tumors can be surgically removed.
- Stage 2B: The tumor is still on one side of the body and it may or may not be completely removed during surgery. Lymph nodes outside the tumor have neuroblastoma cells, yet the cancer has not reached lymph nodes on the opposite side of the body or anywhere else.
- Stage 3: Stage 3 involves one of the following:
- the tumor has spread to the opposite side of the body as a result of an incomplete surgical removal of the original mass
- the tumor is located on one side of the body and has spread to the lymph nodes on the opposite side
- the tumor is centrally located, has spread to the lymph nodes and cannot be surgically removed
- Stage 4: The cancer has spread to distant bones, lymph nodes, skin, liver, bone marrow, or other organs
- Stage 4S: This stage is special; hence the "S." During this stage, the child is no older than one, the cancer is situated on one side of the body, the cancer may have spread to lymph nodes on the affected side of the body, and the neuroblastoma resembles stage 4 in terms of the distant regions affected.
Diagnosis of Neuroblastoma
If neuroblastoma is suspected, a combination of tests may be performed in order to confirm the diagnosis, such as:
- Imaging tests use sound waves, electromagnetic radiation, and other forms of energy to generate images of the body's internal organs and tissue. X-ray, ultrasound, MRI, and CT scans can reveal masses that are associated with the condition.
- Urine and blood tests can detect high levels of urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA), both of which are produced as a result of the neuroblastoma cells creating excess catecholamines.
- Taking tissue from the mass (biopsy) to determine the type of cells and genetic make-up of the tumor. Genetic testing and cell staging will help determine an appropriate treatment plan.
- Bone marrow testing, bone marrow biopsy or bone marrow aspiration procedures may be ordered to see whether or not neuroblastoma has spread to the bone marrow.