glioblastoma multiforme
Pronunciation: glee-oh-blas-TO-ma mul-ti-FOR-may
The most aggressive primary brain tumor (WHO Grade IV), characterized by rapid growth and poor prognosis.
Full Definition
A highly malignant brain tumor that arises from glial cells, representing the most severe form of astrocytoma. Classified as WHO Grade IV, it is characterized by cellular pleomorphism, mitotic activity, microvascular proliferation, and necrosis. The term 'multiforme' refers to the varied histological appearance of the tumor. Glioblastoma multiforme (GBM) has a median survival of 12-15 months despite aggressive treatment. Modern classification increasingly uses molecular markers alongside histology for more precise diagnosis.
Usage
Usage note: Commonly abbreviated as GBM; ensure proper capitalization of 'Grade IV' when specified.
In Context
- "The resection specimen showed classic features of glioblastoma multiforme with pseudopalisading necrosis." — surgical pathology report
- "GBM remains the most challenging brain tumor to treat effectively." — clinical review