Blastoma is a type of tumor that is caused by precursor cells or blasts. Blasts are defined as immature or embryonic tissue that usually contain differentiated or precursor cells. Blastoma serves as the type of cancer that usually occurs in children. Some common forms of blastomas include hepatoblastoma, medulloblastoma, nephroblastoma, neuroblastoma, pancreatoblastoma, pleuropulmonary blastoma, reteinoblastoma, and glioblastoma multiforme.
Signs and Symptoms 
The symptoms of blastomas typically vary depending on the area of the body that is affected. It can affect areas such as the brain, kidneys, liver, nervous system, retina, and bones. A list of signs and systems include pain, weight loss, lethargy, impaired vision, impaired hearing, neurological symptoms, enlarged liver, enlarged spleen, and asymptomatic in early stages.
Causes and Correlations 
Like many other cancers, blastoma has been linked with the mutation in tumor suppressor genes and oncogenes. These mutations enable proliferation of incompletely differentiated cells, and hence create variations between patient to patient.
- “Blastoma” < http://www.rightdiagnosis.com/b/blastoma/intro.htm>