Interdisciplinary Neurosurgery (Dec 2023)
Giant thrombosed cerebral aneurysms: Challenges in their diagnosis
Abstract
Background: Giant cerebral aneurysms are rare lesions which are defined as aneurysms with a diameter greater than 2.5 cm. This group includes giant thrombosed cerebral aneurysms that can remain clinically asymptomatic for a long time or produce symptoms related to the mass effect on surrounding structures which simulates other pathologies, both clinically and radiologically. Thus, their diagnosis is a challenge. Methods: A retrospective review of the patients treated at the Neurosurgery Department in Centro Médico Nacional Siglo XXI from 2010 to 2023 was made. Only those with an initial misdiagnosis and a final diagnosis of giant thrombosed cerebral aneurysm were selected. Results: Eleven patients were included in this series, they all had an initial diagnosis of another pathology, mostly tumors, and a final diagnosis of cerebral aneurysm. Three patients were diagnosed transoperatively and eight patients were diagnosed preoperatively after additional imaging studies were made. Nine patients were treated with open surgery (eight clippings and one bypass), one patient had endovascular treatment and one patient was kept in observation. Four patients passed away, seven had a neurological improvement or remained with the same neurological status. Conclusions: Even with the advances in technology and imaging studies, diagnosis of these lesions is a challenge since they do not have distinct clinical and imaging characteristics. The diagnosis can be suspected in patients with an insidious presentation, slowly progressive symptoms, and neurologic deficit seemingly secondary to lesion mass effect that in MRI and/or CT have rounded, heterogeneous lesions with calcification towards the periphery, with flow voids (even if small), and heterogeneous reinforcement with contrast that seems to diminish towards the periphery. Cerebral angiography can sometimes offer valuable information about the aneurysmal neck and the parent vessel, but it gives little to no information about the dome due to the thrombosis, these lesions can even be invisible.
