Blastoma is a type of cancer that arises in the developing cells of a fetus and typically affects children rather than adults.
This type of cancer can affect different organs, tissues, and systems.
Blastomas are considered treatable in most cases.
Fast facts on blastoma
- Blastoma is a type of cancer that almost always affects children. It occurs as a result of malignancies in the cells of a fetus, also known as blasts.
- The most common blastomas are hepatoblastoma, medulloblastoma, nephroblastoma, and neuroblastoma.
- Tests can include biopsy, blood tests, and scans following a physical examination and questions from a doctor.
- Blastomas, like most childhood cancers, are not preventable, but treatment for most people with the cancer is successful, and survival rates are high.
What is blastoma?
Blastoma mainly affects newborn infants.
Blastoma is a type of cancer.
Cancer cells are those that do not die at the natural point in their life cycle. Instead, they grow uncontrollably, spreading and causing tissue damage.
This type of cancer affects precursor cells in the fetus.
Precursor cells are stem cells that grow into specific types of cells during development.
For this reason, the cancer is most common in children.
Blastoma is thought to be a genetic dysfunction rather than the result of environmental factors.
They are solid tumors resulting from the failure of cells to differentiate properly into their final cell types during fetal or postnatal development. As a result, the tissue remains embryonic. Many blastomas are present at birth.
Individual types may be associated with specific risk factors. For example, hepatoblastoma is more likely in children who have certain genetic syndromes and inherited conditions.
The four most commonly seen blastomas are hepatoblastoma, medulloblastoma, nephroblastoma, and neuroblastoma.
Hepatoblastoma is a tumor of the liver and the most common type of childhood liver cancer, usually appearing in children under the age of 3 years.6
The tumor may be noticed as a painful lump in the abdomen as it grows. Other symptoms can include:
- abdominal swelling
- unexplained weight loss
- loss of appetite
- nausea and vomiting
Some children are more likely than others to develop hepatoblastoma. Risk factors include:
- Aicardi syndrome, a condition mainly affecting females in which a part of the brain, the corpus callosum, is either partly or totally absent from birth
- Beckwith-Wiedemann syndrome, a collection of symptoms present from birth that causes increased height and birth weight, uneven limb growth, and a large tongue
- Simpson-Golabi-Behmel syndrome, a fatal condition that causes overgrowth, distinct facial features, and cognitive difficulties
- familial adenomatous polyposis, a hereditary condition that causes the growth of hundreds or even thousands of polyps in the large bowel
- glycogen storage disease, an inherited disease that affects how the body converts glucose to glycogen and back, affecting the liver and muscles
- very low birthweight
- trisomy 18, or Edwards syndrome, a disorder of the chromosomes
In general, children with hepatoblastoma who have the tumor completely removed and also undergo chemotherapy have a survival rate of 100 percent.
Medulloblastoma occurs in the central nervous system.
Medulloblastoma is the most common tumor affecting the central nervous system in children.
These 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, including:
- behavioral changes, such as listlessness and disinterest in social interaction
- weakness as a result of nerve compression
The 5-year survival rate for patients with high-risk medulloblastoma is better than 60 percent and can be as high as 80 percent in patients with standard-risk tumors.
Wilms’ tumor or nephroblastoma
Wilms’ tumor affects the kidneys and is known as nephroblastoma.
Around nine in every ten kidney cancers that occur during childhood are nephroblastomas. They will most often appear as a single tumor in one kidney, but in rare cases, multiple Wilms’ tumors can occur in both kidneys.
The average Wilms’tumor outgrows the kidney on which it develops by many times.
Neuroblastoma is a tumor of immature nerve cells outside of the brain that often starts in the adrenal glands, which are located near the kidneys. The adrenal glands are part of the endocrine system that produces and secretes hormones.9
It is one of the more common childhood cancers, with around 800 cases in the U.S. each year.
This type of blastoma can also start in the nerve tissue near the upper spine, chest, abdomen, or pelvis.
Neuroblastoma develops when neuroblast cells do not mature properly. Neuroblasts are immature nerve cells found in a fetus, and they 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 type of cancer usually develops in children under the age of 5 years. It is usually found after metastasis and is an aggressive cancer that can spread to the lymph nodes, liver, lungs, bones, and bone marrow
As a sometimes congenital cancer, it might be seen on a prenatal scan.
Roughly 6 percent of all cancers in children 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.
Other, less common types of blastoma include:
- Chondroblastoma: This is a benign bone cancer accounting for less than 1 percent of all bone tumors and usually affecting the long bones of teenage boys
- Gonadoblastoma: This is a tumor seen almost uniquely in people with abnormal sexual development.
- Hemangioblastoma: This is a rare, benign tumor that almost always affects a small space near the brainstem and cerebellum in the bottom of the head. Hemangioblastoma almost always affects young adults and children with the inherited condition von-Hippel-Lindau’s disease.
- Lipoblastoma: This is a benign body fat tissue tumor, usually found in the arms and legs and mostly affecting boys under the age of 5 years
- Medullomyoblastoma: This is a tumor that originates in the rear part of the brain that controls body movement and coordination.
- Osteoblastoma: This is a benign tumor of the bone, usually found in the spine and almost always 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
- Pleuropulmonary blastoma: This is a rare malignant chest tumor, usually found in children aged under 5 years.
- Retinoblastoma: This is a tumor of the 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 biopsy can help diagnose blastoma.
A physician will diagnose separate types of blastoma using specific tests. Testing for hepatoblastoma, for example, may include liver function tests.
Depending on the individual’s age, condition and symptoms, and the type of blastoma suspected, diagnostic tests and procedures can range from removal and biopsy of a tumor to testing whether the cancer has spread or the expected effectiveness of an upcoming treatment.
Tests that may be ordered for a suspected or already-diagnosed blastoma include:
- Blood tests: These involve testing for hormones, proteins, and other tumor markers, as well as assessing the number of cancerous cells using a complete blood count (CBC) test.
- Biopsies and other samples: In a biopsy, laboratory assessment of tumor tissue is done under a microscope. Small segments may be removed with special tools or surgical knives, or the whole tumor may be removed. Examination of the cells by pathologists allows for a definitive diagnosis of the blastoma. Other samples, including bone marrow, may be taken for assessment.
- Ultrasound scans: This is the same imaging method used to visualize unborn babies with sound waves.
- CT, MRI, and PET scans: A range of imaging tests can be used to identify and target blastomas.
Radioisotope scans: Radioactive tracers are introduced into the body and then picked up by a computer-enhanced gamma camera.
Blastomas respond well to treatment and are considered curable.
The treatment strategies available for blastoma are similar to those for other types of cancer, including surgery, radiation therapy and chemotherapy.
The path and success of treatment depend on the type of blastoma and other, individual factors, such as:
- timing of diagnosis
- the stage of cancer
- whether the cancer has spread to other sites
- response to therapy
Almost all cases of localized neuroblastoma can be cured with surgery alone. Most intermediate-risk neuroblastomas and hepatoblastomas, however, might require moderate chemotherapy before surgery.
For medulloblastoma, current treatments cure most patients, although they are associated with long-term toxicity.
Blastomas cannot be prevented as the causes of their development are not yet fully understood.
Risk factors have been identified for some blastomas, such as certain inherited syndromes, but again these links are not well understood and do not enable prevention of the cancer.
However, treatment is often effective, and early diagnosis may contribute to full recovery.