Aneurysm is a limited dilation of a blood vessel due to stretching and protrusion of its wall. It may be congenital and acquired. There are arterial, venous and arteriovenous aneurysms.

Aneurysm of parasellar vessels can mimic a pituitary tumor; rupture of the aneurysm can be fatal to the patient.

Possible signs of chiasm-sellar aneurysm:

  • eye pain and intense headaches;
  • paralysis of cranial nerves;