Giant serpentine aneurysm of the posterior cerebral artery.

We are reporting an unusual case of a giant serpentine aneurysm of the posterior cerebral artery (PCA). We were unable to find a report in the literature of a similar aneurysm. The microsurgical pterional approach was used for temporary clipping of the P-2 segment of the PCA, and the aneurysm was trapped successfully and excised. The discussion includes the operative approach to the giant serpentine aneurysm.