Large Aneurysm of Basilar Artery Tip Mimicking Midbrain Tumor and Causing Unilateral Obstructive Hydrocephalus: a Case Report and Technical Note

Abstract

-Cerebral ventricular system is a sporadic location of intracranial aneurysms including those of basilar artery tip. Treatment of such aneurysms remains challenging regardless of endovascular or microsurgical techniques applied. Basilar tip aneurysm presenting as third ventricular mass is rarely associated with obstructive hydrocephalus, mimicking midbrain expansive process and urging precise diagnostics and prompt treatment. Hence, the management of such patients may be delicate, having an uncertain outcome. We report on a case of a patient with unilateral hydrocephalus caused by large basilar tip aneurysm mimicking a midbrain tumor. We also discuss different operative strategies influencing the outcome, including our own endovascular treatment technical modification. A 62-year-old female patient presented with slightly decreased cognition, minor gait disturbances and urinary incontinence. Computed brain tomography revealed a third ventricle mass with unilateral ventricular dilatation, indicating hypertensive obstructive hydrocephalus. Magnetic resonance and digital subtraction angiography identified the third ventricular mass as a large saccular basilar tip aneurysm. The patient was selected for endovascular treatment followed by cerebrospinal fluid derivation. After aneurysm endovascular occlusion and temporary external ventricular drainage, the symptoms diminished and ventricular dilatation decreased. On post-procedure day 10, the hydrocephalus was relieved and external drainage removed. The patient recovered fully and was discharged without neurological deficit. In conclusion, large basilar tip aneurysms associated with obstructive hydrocephalus are rare and best treated by a combination of endovascular obliteration and cerebrospinal fluid ventricular diversion. The possibility of such an aneurysm should always be considered on the differential diagnosis of cerebral ventricular growths.

Intracranial Aneurysms Mimicking Third Ventricular and adjoining parts Masses Associated with Obstructive Hydrocephalus: Diagnosis and Treatment

“…After these patients underwent aneurysm coil occlusion, one died from cerebral infarction; one died from thrombogenesis of the basilar artery; 25 one had hydrocephalus 21 and received a second operation; one's aneurysm developed and progressively compressed the right thalamus and midbrain, and received a second operation; 20 and one died from aneurysm rupture. 11 Only two patients (including the present case) received satisfactory results, 19 and one patient's prognosis was not reported. 23 In our cases, the results were more favorable: two patients (case 1 and case 4) who received aneurysm coil occlusion achieved good prognosis, particularly case 1, who underwent follow-up after aneurysm coil occlusion for two years and obtained favorable prognosis; and two of the three patients (case 2 and case 3) who underwent aneurysm clipping had unfavorable prognosis due to post-operation hemorrhage.…”

“…We reviewed the literature from PubMed and Embase databases and identi ed 27 cases of aneurysms (including the cases above) presenting as third ventricular masses. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] The average age of the patients was 62 years (range, 14-82 years). In previse cases, all patients were middle-aged and elderly, with one of our cases (case 1) being the rst adolescent reported.…”

“…Third ventricular and adjoining parts masses, including various tumors such as germ cell tumors, glial cell tumors, craniopharyngiomas, 1 meningioma, ependymomas, choroid plexus tumors, 2-4 epidermoid cysts, 5,6 and various vascular malformations 7 can cause obstruction of cerebral spinal uid (CSF) ow and result in hydrocephalus. Identifying the pathological histology of this area is of great clinical importance, especially for rare intracranial aneurysms [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] . These intracranial aneurysms are usually giant, sometimes with thrombogenesis inside, which makes a portion of these aneurysms resemble brain tumors on magnetic resonance imaging (MRI) and computed tomography (CT).…”

Hybrid Microsurgical and Endovascular Approach in the Treatment of Multiple Cerebral Aneurysms: an Illustrative Case Series in Correlation with Literature Data

“…Currently, different endovascular techniques are at disposal for multiple aneurysms, as well as for BA tip aneurysm occlusion regardless of their rupture status ( 22 ). Nevertheless, some authors advocate one-stage, as well as hybrid surgery for all multiple intracranial aneurysms, since the surgical risk for such aneurysms is only slightly higher than for single aneurysms ( 5 , 18 ).…”

Intracranial aneurysms mimicking third ventricular masses: case series and systematic review

“…Third ventricular masses, including various tumors, such as germ cell tumors, glial cell tumors, craniopharyngiomas [ 1 ], meningioma, ependymomas, choroid plexus tumors [ 2 , 3 , 4 ], epidermoid cysts [ 5 , 6 ], and various vascular malformations [ 7 ], can cause obstruction of cerebral spinal fluid (CSF) flow and result in hydrocephalus. Identifying the pathological histology of this area is of great clinical importance, especially for rare intracranial aneurysms [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. These intracranial aneurysms are usually giant, sometimes with thrombogenesis inside, which makes a portion of these aneurysms resemble brain tumors on magnetic resonance imaging (MRI) and computed tomography (CT).…”