幸运飞艇计划

Primary brain tumours represent any tumour that starts in the brain.听The tumors are characterized by uncontrolled cell proliferation, usually in the brain itself, but may also be derived from lymphatic tissue, blood vessels, glands and brain envelopes (meninges). Within the brain itself, brain tumors are听derived from supportive glial cells within the brain (ependymal cells, astrocytes and oligodendrocytes). They may also occur from cranial nerves. 听They also frequently听occur as a result of metastatic spread from cancers primarily located in other organs (metastatic tumours).

Any brain tumor is inherently serious and life-threatening because of its limited space within听听the skull. However, brain tumors are not invariably fatal. 听The treatment strategies depend on a听combination of factors based on听the tumor type, its location, its size and its developmental state. Since the tumors are听well protected within the听skull, early detection occurs only when diagnostic tools are directed at the intracranial cavity. In many cases听detection occurs in advanced stages when the presence of the tumor has caused unexplained symptoms.

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