What is the character of brain tumours?

Depends: I'm not sure what you're asking. Some brain rumors are benign, cured by surgery, such as meningioma. Others are malignant but with a slow growth pattern, such as low grade astrocytoma. Others are rapidly growing, usually fatal, such as glioblastoma multiforme. Brain tumors can also be metastatic from other sites, such as a spread of lung or breast cancer.