Thrombosed Large Middle Cerebral Artery Aneurysm Mimicking an Intra-Axial Brain Tumor: Case Report and Review of Literature

Abstract

This case report presents a fully thrombosed large aneurysm of middle cerebral artery mimicking an intra-axial brain tumor in a 54-year-old male patient. A small mass like lesion was found incidentally in right frontal area. Brain magnetic resonance image showed dark signal intensity on T2-weighted images and peripheral high signal intensity on T1-weighted images with peripheral rim enhancement. We considered intra-axial tumors such as glioma or metastatic tumor as a differential diagnosis. The lesion was approached transcortically, and intraoperatively, the lesion was found to be a large thrombosed aneurysm originating from the lateral lenticulostriate artery of right middle cerebral artery. One vascular clip was applied at the parent artery, and the thrombosed aneurysm was totally removed. There have been many reports of other intracranial lesions wrongly diagnosed as intracranial neoplasms. And thrombosed aneurysms mimicking intracranial neoplasm have been reported in 4 cases previously. According to those case reports, there were no efficient imaging tools to differentiate between these thrombosed aneurysms and intracranial neoplasms. We reviewed those reports and considered about the efficient method to diagnosed accurately before surgery. To sum up, when a patient presents with an intracranial lesion lying on the course of major or distal cerebral arteries, the surgeon should have thrombosed aneurysm in mind as one of the differential diagnosis and be prepared when surgically treating such lesions.

Ring enhanced aneurysm due to vasa vasorum of aneurysm wall mimicking a metastatic brain tumor

“…In the literature, nine of ten cases underwent aneurysm trapping and removal of the aneurysm. [ 5 , 7 , 10 , 13 , 14 , 17 , 19 ] In these cases of thrombosed aneurysms, though there was a low possibility of rupture because they were fully thrombosed, the parent artery could be completely controlled by trapping and removal of the aneurysm to prevent bleeding and reduce the mass effect.…”

Distal middle cerebral artery dissection with concurrent completely thrombosed aneurysm manifesting as cerebral ischemia. A case report and review of the literature

“…Magnetic Resonance may demonstrate a lumen with heterogeneous signal on T1- and T2-weighted images, “onion skin” appearance on noncontrast T1 weighted images, a flow void sign, thrombus non-enhancement or rim enhancement along the thrombus margin [12 , 13] . Eleven similar cases have been reported in the literature ( Table 1 ) and were commonly mistaken for neoplasms on initial imaging work up with the final diagnosis commonly established during surgery [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] . Only 3 aneurysms affected the middle cerebral artery.…”

Apoplexy inside a giant medial sphenoid wing meningothelial (Grade I) meningioma: An extremely rare but a potentially dangerous complication

“…Such a presentation generally points toward an underlying vascular pathology which may range from an aneurysm rupture to hypertensive intracranial hemorrhage. [56]…”