Blastoma is a type of cancer that occurs in the developing cells of a fetus or child. It typically affects children rather than adults.
There are many types of blastoma. They can affect different organs, tissues, and systems. Treatment is available in most cases, but the outlook depends on a range of factors, including the type of blastoma.
All cells have a life cycle. They exist for a certain amount of time, and then they die. The body’s cells are constantly renewing themselves.
Cancer cells are ones that do not die at the natural time in their life cycle. Instead, they grow uncontrollably, spreading and causing tissue damage.
Blastoma is cancer that affects a type of stem cell known as a precursor cell in a fetus. A precursor cell is one that can become any type of body cell.
A developing baby that is not yet born has more precursor cells than an adult because the body is still forming. For this reason, blastoma is most common in children.
Scientists believe that blastoma happens because of a genetic dysfunction rather than environmental factors.
Blastomas are solid tumors. They form when cells fail to differentiate properly into their intended cell types before birth or in infancy and early childhood.
As a result, the tissue remains embryonic. In a child with blastoma, the condition is usually present at birth.
Certain syndromes and inherited conditions can make specific types of blastoma more likely.
For example, hepatoblastoma, which affects the liver, is more likely in children who have certain genetic features.
The most common types of blastomas are:
- pleuropulmonary blastoma
Symptoms can include:
- abdominal swelling and pain
- unexplained weight loss
- loss of appetite
- nausea and vomiting
- yellowing of the skin and whites of the eyes
Children are more likely than others to develop hepatoblastoma if they are born with the following conditions:
Aicardi syndrome: This condition mainly affects females. A part of the brain, the corpus callosum, is either partly or totally absent from birth.
Beckwith-Wiedemann syndrome: This is a syndrome that causes overgrowth and is present from birth. Symptoms include increased height and birth weight, uneven limb growth, and a large tongue.
Simpson-Golabi-Behmel syndrome: This is a rare condition that causes overgrowth, distinct facial features, and cognitive difficulties.
Familial adenomatous polyposis: This is a hereditary condition that causes the growth of hundreds or possibly thousands of polyps in the large bowel.
Glycogen storage disorder: This is an inherited disease that affects how the body converts glucose to glycogen and back again. It affects the liver and muscles.
Trisomy 18, or Edwards syndrome: This is a disorder of the chromosomes.
Treatment for blastoma is similar to that for adult cancers, but the options will depend on the individual and the type of tumor. If the tumor is small, the surgeon can typically remove it completely. A cure is possible in these cases.
Wilms tumor or nephroblastoma
Wilms tumor, or nephroblastoma, affects the kidneys.
Around nine in every 10 kidney cancers that occur during childhood are nephroblastomas.
They will most often appear as a single tumor in one kidney. Rarely, multiple Wilms tumors can occur in both kidneys. The average Wilms tumor outgrows the kidney on which it develops by many times.
The outlook for this cancer depends on the type of tumor. An anaplastic Wilms tumor is harder to cure than one that is not anaplastic.
On average, if a person has a diagnosis of a Wilms tumor before the age of 15 years, they have up to an 88 percent chance of surviving at least another 5 years, according to the National Cancer Institute.
Medulloblastoma is a malignant brain tumor.
The tumors typically form in a part of the brain called the cerebellum, which controls movement, balance, and posture. They are fast-growing tumors that can create a range of symptoms in a growing child, including:
- behavioral changes, such as listlessness and disinterest in social interaction
- ataxia, resulting from a lack of muscle coordination
- weakness as a result of nerve compression
According to researchers who published a study in 2014, current treatment can resolve most cases of medulloblastoma, but there may be long-term side effects.
The outlook depends on the type of tumor. For a standard-risk tumor, there is a chance of up to 80 percent that the child will survive for 5 years or longer. For those with high-risk medulloblastoma, the chance of surviving for 5 years or longer is more than 60 percent.
In those who develop tumors before the age of 3 years, there is a higher risk of the tumor coming back.
Neuroblastoma is a tumor of immature nerve cells outside of the brain. It often starts in the adrenal glands, which are near the kidneys. The adrenal glands are part of the endocrine system that produces and secretes hormones.
Neuroblastoma can also start in the nerve tissue near the upper spine, chest, abdomen, or pelvis.
It is the most common cancer in infants under 1 year of age. There are around 800 new cases in the U.S. each year. In almost 90 percent of cases, the child receives a diagnosis before the age of 5 years, often at the age of 1 to 2 years old. Rarely, an ultrasound scan may detect it before birth.
Neuroblastoma develops when neuroblast cells do not mature properly. Neuroblasts are immature nerve cells that usually mature into nerve cells or cells in the adrenal gland. If they do not, they may instead develop into a tumor that grows aggressively.
This is aggressive cancer that can spread to the lymph nodes, liver, lungs, bones, and bone marrow. In two out of three cases, diagnosis occurs after metastasis, when the cancer has already spread.
Roughly 6 percent of all cancers in children in the U.S. are neuroblastomas. Children with low-risk neuroblastoma often have a survival rate higher than 95 percent, but those with a higher-risk presentation of the disease have an outlook of between 40 and 50 percent.
A child with low-risk neuroblastoma has a 95-percent chance of surviving for 5 years or longer after diagnosis. For those in a high-risk group, there is a 50 percent chance of living for at least 5 years.
This type of blastoma occurs in the chest, and specifically in the lungs. It is a rare malignant chest tumor that usually appears in children aged under 5 years old.
The child may have difficulty breathing.
Other symptoms that may resemble those of pneumonia include:
- a fever
- a cough
- loss of energy
- low appetite
Pleuropulmonary blastoma is thought to be due to genetic factors. Depending on the type, treatment can resolve up to 89 percent of cases, although the tumors may come back.
Other, less common types of blastoma include:
Chondroblastoma: This is a benign bone cancer that accounts for fewer than 1 percent of all bone tumors. It usually affects the long bones of teenage boys.
Gonadoblastoma: A person with this kind of tumor usually has irregularities in the development of their reproductive system, too.
Hemangioblastoma: This is a rare, benign tumor that almost always affects a small space near the brainstem and cerebellum, at the bottom of the head. It usually affects young adults and children with the inherited condition von-Hippel-Lindau’s disease.
Lipoblastoma: This is a benign, body-fat tissue tumor that usually occurs in the arms and legs. It mostly affects boys under the age of 5 years.
Medullomyoblastoma: This is a tumor that originates in the rear part of the brain, in the area that controls movement and coordination.
Osteoblastoma: This is a benign tumor of the bone that usually affects the spine. It mostly appears between childhood and young adulthood.
Pancreatoblastoma: This is a tumor of the pancreas that affects children between the ages of 1 and 8 years.
Pineoblastoma: This is a lesion of the pineal region of the brain. The pineal gland produces melatonin and plays a role in regulating the body clock.
Retinoblastoma: This is a tumor that affects a person’s eye.
Sialoblastoma: This is a tumor affecting the major salivary glands.
Gliomas are a type of brain cancer. About half of all gliomas in adults are glioblastomas.
A doctor will use tests to diagnose separate types of blastoma. Testing for hepatoblastoma, for example, may include checking a person’s liver function.
The tests vary, depending on the individual’s age, condition, symptoms, and the type of blastoma they may have.
Tests and procedures can range from removal and biopsy of a tumor to testing whether cancer has spread or the expected effectiveness of an upcoming treatment.
Blood tests: These can detect signs that a tumor is present, such as hormonal features and specific proteins. A complete blood count can help to assess the number of cancerous cells.
Biopsies and other samples: In a biopsy, a doctor takes a sample of tissue or bone marrow for investigation in a laboratory. They may remove small segments or the whole tumor.
Radioisotope scans: A doctor introduces radioactive tracers into the body and uses a computer-enhanced gamma camera to detect their movement. This can show unusual features or activity in the body.
Blastomas respond well to treatment, and doctors consider them curable. The treatment strategies for blastoma are similar to those for other types of cancer.
The path and effectiveness of the treatment will depend on the type of blastoma and other, individual factors, including:
- the person’s age
- when the diagnosis happens
- the stage of cancer
- whether cancer has spread
- the person’s response to therapy
Surgery alone can resolve most cases of localized neuroblastoma. Most intermediate-risk neuroblastomas and hepatoblastomas, however, might need moderate chemotherapy before surgery.
For medulloblastoma, current treatments cure most people, although the treatment may have some long-term side effects.
It is not possible to prevent blastomas. While having certain inherited syndromes may increase the risk of certain blastomas, these links are not well understood, and it is not currently possible to prevent these syndromes occurring.
However, treatment is often effective, and early diagnosis may contribute to full recovery.