Unruptured middle cerebral artery aneurysm associated with a duplicated middle cerebral artery and a dolichoectasic anterior cerebral artery.

Duplicated middle cerebral artery (DMCA) has been reported in 0.7%-2.9% of autopsy cases, and sme reports have described aneurysms in the MCA. Both ruptured and unruptured aneurysms in the MCA have been reported, often requiring surgical intervention. During surgery for aneurysm in DMCA, care must be taken to avoid damaging the MCA, which supplies the territory of the temporopolar artery and the anterior and/or middle temporal artery. Regarding dolichoectasia of intracranial arteries, a relationship between dolichoectasia and ischemic brain lesions, especially lacunar infarctions, has been noted. We report a case with unruptured MCA aneurysm associated with DMCA and a dolichoectasic anterior cerebral artery. In this case, surgical intervention was not prioritized because of the narrowed and calcified parent artery of the aneurysm. In selecting treatment for a patient with multiple vascular anomalies, the pathophysiology of each anomaly should be estimated carefully.