Giant aneurysm associated with a large cyst. Case illustration

Neuroendoscopic cyst fenestration for delayed enlargement of perianeurysmal cyst formation through long-term follow-up after endovascular treatment: A case report and review of literature

Background

Perianeurysmal cyst formation after endovascular treatment of cerebral aneurysms is a rare complication; however, the number of reports has gradually increased in recent years due to the development of several endovascular treatments.

Case Description

We present a case of delayed perianeurysmal cyst enlargement 8 years after endovascular treatment for multiple recurrences of a large cerebral aneurysm in the anterior communicating artery. The patient presented with obstructive hydrocephalus caused by an enlarged perianeurysmal cyst. The patient underwent cyst fenestration using neuroendoscopy and ventriculoperitoneal shunting, recovered from the clinical symptoms, and had a good prognosis. Histopathological findings showed that the cyst wall contained a fibrotic layer under the monoependymal layer with hemosiderosis without evidence of neovascularization or inflammatory cell infiltration. These findings suggest that the origin of the perianeurysmal cyst wall is not the aneurysm itself but the adjacent brain tissue.

Conclusion

Perianeurysmal cysts can develop during long-term follow-up, and clinicians should consider surgical treatment, including cyst fenestration, using neuro-endoscopy if the cyst presents with clinical symptoms.

A Case of a Perianeurysmal Cyst Following Stent-Assisted Coil Embolization of an Unruptured Vertebral Artery Aneurysm

Objective

To report the rare case of a patient with a perianeurysmal cyst following stent-assisted coil embolization of an unruptured vertebral artery aneurysm.

Case Presentation

A 63-year-old woman underwent stent-assisted coil embolization for an unruptured vertebral artery aneurysm embedded in the brainstem (pons). Complete occlusion of the aneurysm was successfully achieved. However, subsequent magnetic resonance imaging (MRI) conducted 8 months after the procedure showed perilesional edematous changes surrounding the aneurysm, and at 20 months, cyst formation was observed in the vicinity of the aneurysm. Progressive enlargement of the cyst eventually led to the development of paralysis and dysphagia, necessitating cyst fenestration surgery. Although postoperative reduction in the cyst size was achieved, the patient experienced complications in the form of aspiration pneumonia and bacterial meningitis, which resulted in a life-threatening condition.

Conclusion

Aneurysms embedded in the brain parenchyma should be carefully followed up, recognizing the risk of perianeurysmal cyst formation after coil embolization.

Perianeurysmal parenchymal cysts – Case series and literature review

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Intracranial cysts are associated with a number of vascular lesions.

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They predominantly occur in larger, partially-thrombosed aneurysms and in older patients.

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There is a trend towards enlargement over time if untreated and a likelihood of recurrence following treatment.

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We hypothesise the cysts arise either from dilated Virchow-Robin spaces and/or inflammatory processes.

Large Parenchymal Perianeurysmal Cyst: A Case Report

Parenchymal perianeurysmal cysts are rare. We report a case of 50-year-old woman who presented with persistent headaches and episodes of vomiting for the last 2 months. Magnetic resonance imaging of the brain showed a well-defined solitary cystic lesion with a mural nodule measuring 5.4 × 5.2 × 4.6 cm in the right basifrontal region. The mural nodule was cortically based. It was hypointense on T2-weighted fluid-attenuated inversion recovery and showed intense contrast enhancement with few nonenhancing areas—no evidence of diffusion restriction. The cyst wall was nonenhancing, and magnetic resonance angiogram was unremarkable. Differential diagnoses included intra-axial gliomas such as ganglioglioma and pleomorphic xanthoastrocytoma. Right pterional craniotomy and a transcortical approach were made. Subtotal excision of cyst and clipping of right middle cerebral artery bifurcation thrombosed aneurysm were done. After 6 months of follow-up, patient is stable without any deficits. A parenchymal perianeurysmal cyst is a rare entity; it is crucial to be considered a differential diagnosis in any cystic lesion with the mural nodule.

Intracranial perianeurysmal cysts: case series and review of the literature

BACKGROUND

Intracranial perianeurysmal cysts are a rare finding associated with cerebral aneurysms. Patients may present with symptoms secondary to mass effect from perianeurysmal cysts requiring drainage. These lesions can masquerade as neoplasms if dedicated vascular imaging is not performed, leading to misdiagnosis.

METHOD

A retrospective search of our database was done for intracranial aneurysms that have been treated between 1998 and 2020. A literature search was then performed on PubMed and Google Scholar with the search terms 'aneurysm', 'intracranial/intracerebral', 'cyst', and 'perianeurysmal cyst'. Patient demographics, aneurysms and cysts characteristics were then summarized as a table and in the discussion.

RESULTS

Three cases where intracranial aneurysm had associated perianeurysmal cysts were found in our database. Combined with the available literature a total of 19 cases of perianeurysmal cysts have thus far been reported since this entity was first described in 2002. A significant number of perianeurysmal cysts (5/19) required intervention. In 5/19 cases the patient presented with a perianeurysmal cyst without a history of subarachnoid hemorrhage. Of the 10 cases where aneurysm follow-up was reported there were 5 cases where there was aneurysm recurrence necessitating re-treatment.

CONCLUSION

Significant variability exists in the patient demographics, aneurysm and cyst characteristics of perianeurysmal cysts. This suggests that there is no single unified etiology and pathogenesis. These lesions are a rare finding and at present do not appear to carry diagnostic or prognostic significance. Management of perianeurysmal cysts is case-dependent and intervention should be considered when treating the related aneurysm, especially in patients with secondary symptoms.

Cerebral Aneurysm Associated with an Arachnoid Cyst: 3 Case Reports and a Systematic Review of the Literature

BACKGROUND

Arachnoid cysts and intracranial aneurysms are not rare, but it is unusual for an aneurysm to be associated with an arachnoid cyst. The objective of this study was to reveal the association between arachnoid cysts and intracranial aneurysms.

METHODS

Methods included to report 3 cases with these 2 pathologies and to perform a systematic review of the English and Japanese literature using PubMed, Scopus, and Ichushi Web.

RESULTS

The first case was of a 46-year-old man with a subarachnoid hemorrhage on the basal cistern and bilateral arachnoid cysts in the middle fossa, the second was that of a 29-year-old woman with a subarachnoid hemorrhage at the basal cistern and an arachnoid cyst in the left middle fossa, and the third was that of a 60-year-old man with a right putaminal hemorrhage and contralateral unruptured aneurysm and arachnoid cyst. A literature search for similar cases found 27 patients.

CONCLUSIONS

It was difficult to diagnose a ruptured aneurysm in some cases with an arachnoid cyst because computed tomography scan showed atypical findings, such as no hemorrhage, intracystic localized hemorrhage, or subdural hematoma. This review revealed that aneurysms and arachnoid cysts were significantly located ipsilaterally and that they occurred together in relatively young patients.

Delayed Hydrocephalus and Perianeurysmal Cyst Formation After Stent-Assisted Coil Embolization of a Large, Unruptured Basilar Apex Aneurysm: A Case Report and Literature Review

PURPOSE

Endovascular aneurysm embolization possesses a unique set of infrequently seen complications distinct from those associated with microsurgical clipping, which may arise after an otherwise uncomplicated coil embolization procedure, including postembolization, hydrocephalus, and perianeurysmal cyst formation.

DESIGN

The authors report an illustrative case of 2 rarely seen complications of aneurysm embolization with literature review.

METHODS

We present a case of a basilar apex aneurysm that was treated with endovascular coil embolization with multiple Cerecyte (Micrus Endovascular, San Jose, Calif) coils and 2 Enterprise (Codman & Shurtleff, Inc, Raynham, Mass) stents.

RESULTS

Postembolization angiography demonstrated complete aneurysm obliteration without distal branch occlusion or other complication. Twenty-two months after the embolization, however, the patient presented with progressively worsening headaches. Repeat magnetic resonance imaging revealed hydrocephalus and a perianeurysmal cyst measuring 1 × 2 cm adjacent to the previously coiled basilar apex aneurysm. After endoscopic third ventriculostomy, the patient experienced significant relief of her headaches and was discharged to rehabilitation.

CONCLUSIONS

Clinicians should be aware that worsening or new neuro-ophthalmic findings may be the presenting sign of postembolization hydrocephalus or perianeurysmal cyst formation.

Intracranial Perianeurysmal Cyst: Still a Dilemma

Intracranial perianeurysmal cysts constitute an extremely rare entity with very few cases reported in the literature. These cysts present an unknown mechanism of formation and clinical significance. Several theories based on isolated cases have been proposed, without drawing a clear conclusion. It is also unknown if follow-up with imaging techniques is required or which is the most appropriate treatment. We describe an atypical case handled with a satisfactory outcome after endovascular treatment, suggesting the importance of hydrodynamic forces as the key factors in the mechanism of formation. We believe that this case can help in future analysis of this rare entity.

Rupture of a small middle cerebral artery aneurysm into middle fossa arachnoid cyst presenting as a chronic subdural haematoma

The rupture of an aneurysm into an arachnoid cyst and subdural space is unusual. A 25-year-old man was admitted 2 weeks after having undergone a burr hole drainage for a chronic subdural haematoma elsewhere. An angiogram revealed a small aneurysm at the bifurcation of the middle cerebral artery. The aneurysm was clipped and the cyst communicated with the basal cisterns. To the best of our knowledge, this is the first report of an association of an aneurysm of the middle cerebral artery with an arachnoid cyst presenting as a chronic subdural haematoma.

Association between an arachnoid cyst and intracranial aneurysms misdiagnosed as a cystic tumor with a mural nodule

✓The authors report on a 63-year-old man initially admitted to an outside hospital for altered mental status and respiratory distress. A head computed tomography scan disclosed a right frontal cystic mass, suspected to be a neoplasm. An open biopsy was performed at an outside institution, and on visualization of the cyst, an aneurysm was found incidentally. Postoperatively, an angiogram and magnetic resonance image confirmed the presence of a distal right M1 segment aneurysm. The patient was transferred to our institution where, in addition to the middle cerebral artery lesion, a right anterior choroidal artery aneurysm was found intraoperatively; the necks of both aneurysms were clipped successfully. A review of the literature revealed 14 additional cases of intracranial aneurysms associated with arachnoid cysts. Data in the present report highlight the importance of considering an intracystic aneurysm in the differential diagnosis when reviewing cases that involve a cystic mass with a mural nodule. The authors provide a comprehensive summary of documented cases of aneurysms associated with arachnoid cysts. In addition, they include a discussion of prevailing thoughts on the origin and evolution of arachnoid cysts.

Parenchymal Perianeurysmal Cyst in the Brain: Case Report

OBJECTIVE AND IMPORTANCE:

Parenchymal perianeurysmal cysts are rare, and only seven cases have been reported. We present a case report with a 30 month follow-up on this topic. The possible etiopathogenetic mechanisms of cyst formation are discussed.

CLINICAL PRESENTATION:

A 54-year-old man with a 5–month history of headache and a computed tomography scan showing a giant parenchymal cyst located in the right temporal lobe with a mural enhanced nodule was admitted to our neurosurgical department with the diagnosis of cystic brain tumor. Magnetic resonance imaging followed by digital subtraction angiography identified the enhancing nodule as a large right middle cerebral artery aneurysm.

INTERVENTION:

Surgical treatment was performed; the aneurysm was clipped and the cyst evacuated. Postoperative digital subtraction angiography confirmed the clipping of the aneurysm at the neck. Serial magnetic resonance imaging controls showed the permanent collapse of the cyst.

CONCLUSION:

Parenchymal perianeurysmal cysts are rare. In the presence of parenchymal cysts neighboring main vessels, the possibility of a perianeurysmal cyst should be considered. In regard to the etiopathogenetic mechanisms responsible for the cyst development, the action of multiple coexisting factors seems to be the most applicable.

Cerebral infarction and fluid collection due to an enlarged dissecting aneurysm of the middle cerebral artery--case report

A 53-year-old man presented with cerebral infarction associated with a dissecting aneurysm of the left middle cerebral artery (MCA), with enlargement and fluid collection. Anticoagulant therapy was performed as the first stage treatment for cerebral infarction. Serial magnetic resonance imaging showed that the dissecting aneurysm had enlarged and fluid collection adjacent to the aneurysm had developed since the first admission. Surgery was performed to ligate the MCA proximal to the aneurysm. Intraoperative findings showed the branch of the MCA was obstructed by intramural hemorrhage of the aneurysm dome. Histological examination showed direct obstruction of the MCA branch artery by intramural hemorrhage of aneurysm dome had caused the cerebral infarction and the fluid collection surrounding the aneurysm resulted from minor leakage or exudation of intramural hemorrhage to the outer surface of the dissecting aneurysm.

Development of a pontine cyst after endovascular coil occlusion of a basilar artery trunk aneurysm: case report

OBJECTIVE AND IMPORTANCE

Cyst formation within the brain parenchyma after endovascular coil occlusion of an intracranial aneurysm is a previously undescribed occurrence. We describe a 70-year-old woman who presented with a symptomatic pontine cyst 1 year after uncomplicated stenting and Guglielmi detachable coil occlusion of an unruptured basilar artery trunk aneurysm.

CLINICAL PRESENTATION

A 70-year-old woman presented with an episode of transient dysequilibrium and gait difficulty. Magnetic resonance imaging and cerebral angiography demonstrated a 15-mm distal basilar artery trunk aneurysm. Endovascular stenting and coil occlusion of the aneurysm were performed without technical complications. One year after the initial treatment, the patient developed progressive dysarthria, dysphagia, diplopia, and left hemiparesis. A large pontomesencephalic cyst adjacent to the coiled basilar aneurysm was identified on magnetic resonance imaging scans.

INTERVENTION

A subtemporal craniotomy and decompression of the pontomesencephalic cyst were performed. The patient's symptoms of brainstem dysfunction improved temporarily but recurred within 2 months, necessitating reoperation for cyst drainage and placement of a cyst-peritoneal shunt.

CONCLUSION

Intra-axial cyst formation after stenting and endovascular occlusion of an intracranial aneurysm is an unusual occurrence and should be considered in the differential diagnosis of new neurological deficits after endovascular treatment. The pathophysiological mechanism of cyst formation in this case is not known.