Giant aneurysm of the distal anterior cerebral artery: associated with an anterior communicating artery aneurysm and a dural arteriovenous fistula.

We describe an unusual case of a giant pericallosal artery aneurysm, producing psychomotor depression from mass effect, associated with a smaller aneurysm of the anterior communicating artery, a dural arteriovenous fistula, and a meningioma. Magnetic resonance imaging (MRI) and cerebral angiography demonstrated the giant aneurysm and the meningioma. Cerebral angiography provided a detailed appreciation of the cerebral circulation, including both aneurysms, the dural arteriovenous fistula, and the potential collateral supply to the involved anterior cerebral distribution. The anterior communicating artery aneurysm was successfully clipped as was the distal anterior cerebral branch supplying the giant aneurysm before its resection. The patient made a full recovery but with persisting, slight dysphasia. We conclude that computed tomography, cerebral angiography, and MRI are of specific value in the assessment of giant aneurysms, but only angiography can provide detailed characterization of the aneurysm and demonstrate other possible cerebrovascular pathology such as multiple aneurysms and arteriovenous fistulas.