Glioblastomas are highly malignant, Grade IV gliomas. They arise in the brain.
Depending on their clinical history, they are of two types:
1. Primary Glioblastoma
2. Secondary glioblastoma
Histologically these two types are indistinguishable. However, several differences have been described especially in their clinical presentation and gene mutations that lead to the development of these two forms of glioblastoma. The term Glioblastoma is often used for Primary glioblastoma.
For more information, please read the following articles:
Ohgaki & Kleihues, 2007. Genetic pathways to primary and secondary glioblastoma. Am J Pathol. 170(5), 1445-53. PMID-17456751, Full-Text Links: amjpathol, PMC