Are tumors of the central nervous system that originate from the vascular system usually during middle-age.
The rarest central nervous system tumors, accounting for less than 2%.
Usually occur in adults, but may appear in VHL syndrome at much younger ages.
Risk similar among genders.
Usually occur in either side of the cerebellum, the brain stem or the spinal cord.
These tumors occur in other sites such as the spinal cord and retina.
May be associated with other diseases such as polycythemia, pancreatic cysts and Von Hippel-Lindau syndrome (VHL syndrome).
Most commonly composed of stromal cells in small blood vessels and usually occur in the cerebellum, brain stem or spinal cord.
They are classed as grade one tumors under the WHO classification system, and are
composed of endothelial cells, pericytes and stromal cells.
In VHL syndrome the von Hippel-Lindau protein (pVHL) is dysfunctional, usually due to mutation and/or gene silencing.
pVHL is involved in the inhibition of hypoxia-inducible factor 1 α (HIF-1α) by ubiquitin mediated proteosomal degradation.
In these dysfunctional cells pVHL cannot degrade HIF-1α, causing it to accumulate.
HIF-1α causes the production of vascular endothelial growth factor, platelet derived growth factor B, erythropoietin and transforming growth factor alpha, which act to stimulate growth of cells within the tumor.
The primary diagnosis is made with a computed tomography scan.
The treatment is surgical excision of the lesion.
Recurrence of the tumor or more tumors at a different site develop in approximately 20% of patients.
Gamma Knife Radiosurgery can successfully treat recurrence.
Excision is possible in most cases and permanent neurologic deficit is uncommon.
Patients with VHL syndrome have a worse prognosis than those who have sporadic tumors since those with VHL syndrome usually have more than one lesion.