What Is Neuroblastoma?
Neuroblastoma is a solid tumor cancer that develops from immature nerve cells, called neuroblasts, most often in infants and children under five. It typically originates in the adrenal glands located on top of the kidneys but can also appear in nerve tissue in the neck, chest, abdomen, or pelvis.
This cancer is unique because its behavior varies widely. In some infants, tumors may disappear without treatment as the cells mature or die off. In others, the cancer can be highly aggressive, spreading quickly to other parts of the body like the bone marrow, liver, and skin. The symptoms a child experiences are often the first clue and depend heavily on the tumor's size, location, and whether it has spread.
Symptoms Based on Tumor Location
The initial signs of neuroblastoma are often caused by the tumor pressing on nearby tissues. The specific symptoms depend entirely on where the tumor is growing.
Tumors in the Abdomen
This is the most common location for neuroblastoma. A tumor in the abdomen, often on an adrenal gland, may cause a swollen belly or a hard, painless lump that can be felt under the skin. As it grows, it can press on the stomach or bowels, leading to a poor appetite, a feeling of fullness after small meals, stomach pain, or constipation.
Tumors in the Chest
A tumor in the chest can press on the lungs or airways, causing a persistent cough, wheezing, or difficulty breathing. It may also compress a large vein, leading to swelling in the face, neck, and arms. If the tumor affects nerves in the upper chest, it can cause a droopy eyelid, a smaller pupil in one eye, and decreased sweating on one side of the face.
Tumors Near the Spine
When a tumor arises from nerve tissue alongside the spine and grows into the spinal canal, it can press on the spinal cord. This pressure can cause weakness in the legs, making it difficult for a child to stand, walk, or crawl. It may also lead to changes in bowel or bladder control, such as sudden constipation or trouble urinating.
Signs of Widespread (Metastatic) Neuroblastoma
When neuroblastoma spreads beyond its original location, it can cause more general, body-wide symptoms. These signs often indicate the cancer has moved to distant sites.
Spread to Bones and Bone Marrow
Metastasis to the bones is common and can cause bone pain, which a young child might show as unexplained irritability, fussiness, or a limp. If the cancer infiltrates the bone marrow, where blood cells are made, it can disrupt production. This can lead to:
- Anemia (low red blood cells), causing pale skin and fatigue.
- Frequent infections (low white blood cells).
- Easy bruising or bleeding (low platelets).
General Signs of Illness
Widespread cancer can make a child seem generally sick. This may include a persistent low-grade fever not caused by an infection, unexplained weight loss, and a noticeable lack of energy. The child may seem tired, listless, or irritable for no clear reason, which can be mistaken for common childhood illnesses.
Distinctive Eye Signs
A classic sign of widespread neuroblastoma involves the eyes. If cancer spreads to the bones of the eye sockets, it can cause bleeding that results in dark, bruise-like circles, often called "raccoon eyes." A tumor growing behind the eye can also push it forward, causing one or both eyes to bulge (proptosis).
Systemic and Paraneoplastic Symptoms
Sometimes, neuroblastoma causes symptoms that are not related to the tumor's physical pressure. These effects, known as paraneoplastic syndromes, occur when the tumor releases hormones or triggers an abnormal immune response that affects other parts of the body.
Hormone-Related Symptoms
- High Blood Pressure and Irritability: Tumors can release high levels of "fight-or-flight" hormones (catecholamines). This flood of stress hormones can cause persistently high blood pressure, a rapid heartbeat, excessive sweating, flushed skin, and feelings of extreme irritability or anxiety.
- Severe Watery Diarrhea: Some tumors produce a substance called vasoactive intestinal peptide (VIP). This causes the intestines to secrete large amounts of water, leading to severe, chronic diarrhea that does not respond to standard treatments. This condition, known as Kerner-Morrison syndrome, can cause dangerous dehydration and mineral imbalances.
Autoimmune Reactions
- Uncontrolled Movements (Opsoclonus-Myoclonus-Ataxia Syndrome - OMAS): In this rare syndrome, the body’s immune system mistakenly attacks parts of the nervous system while trying to fight the tumor. This causes rapid, chaotic eye movements ("dancing eyes"), jerky muscle spasms in the limbs ("dancing feet"), and a loss of coordination (ataxia) that affects balance and walking. Children with OMAS often have a less aggressive form of neuroblastoma.
Other Rare Signs
- "Blueberry Muffin" Skin Nodules: Seen almost exclusively in infants with widespread disease, this sign involves small, firm, non-tender, bluish-purple bumps appearing on the skin. These nodules are tiny tumor deposits that have spread to the skin, giving it an appearance nicknamed a "blueberry muffin" rash. Despite being a sign of metastasis, it is often associated with a type of neuroblastoma in infants that has a very good prognosis.
