Brain tumor staging

WHO histologic grading for CNS tumors:

'

Grade I:

• Lesions with low proliferative potential, a frequently discrete nature, and the possibility of cure following surgical resection alone
• Juvenile pilocytic astrocytoma, subependymal giant cell astrocytoma

Grade II:

• Lesions that are generally infiltrating and low in mitotic activity but recur; some tumor types tend to progress to higher grades of malignancy
• Diffuse astrocytoma, oligodendroglioma, oligoastrocytoma

Grade III:

• Lesions with histologic evidence of malignancy, generally in the form of mitotic activity, clearly expressed infiltrative capabilities, and anaplasia
• Anaplastic astrocytoma, anaplastic oligoastrocytoma, anaplastic oligoastrocytoma

Grade IV:

• Lesions that are mitotically active, necrosis-prone, and generally associated with a rapid preoperative and postoperative evolution of disease
• Glioblastoma