They arise next to the ependyma-lined ventricular system including the central canal of the spinal cord
In children, the most common site is near the fourth ventricle areas and in adults it is spinal cord
they are commonly occur in patients with neurofibromatosis type 2.
This is because of the mutation in the NF2 gene on chromosome 22
Microscopically one characteristic feature you need to remember is the perivascular Pseudorosettes. In which the tumour cells are arranged around vessels with an intervening zone consisting of thin ependymal processes.