Third ventricular choroid plexus arteriovenous malformation simulating a colloid cyst. Case report

Choroid plexus arteriovenous malformations: A systematic review

To systematically review the reported outcomes and complications of different treatment options for choroid plexus arteriovenous malformations (AVMs), specifically focusing on surgical resection and endovascular embolization. A systematic literature review was performed using a PubMed query for studies published between January 1975 and July 2021. All studies describing the clinical presentation, management, and outcome of confirmed choroid plexus AVM cases were included. A total of 20 studies were included in the final analysis. Of these, 18 were singlepatient case reports, one article contained two patients, and a single study was a cohort of 24 patients. Patient age ranged from one day to 61 years, with a mean of 31.8±20.4 years. Most choroid plexus AVMs were located in the lateral ventricles (14 patients, 70.0%), while there were four (20.0%) located in the third ventricle, and two in the fourth ventricle (10.0%). Almost all patients were treated with surgical resection (18 patients, 90%). In 14 patients (77.8%), complete resection of the AVM was achieved. A residual AVM was reported in one case (5.6%). Most patients were reported to have improved from their presentation status over time (14 patients, 70.0%). Presence or absence of long-term sequelae (e.g., neurologic deficits) were reported for 14 patients (70%). Eleven of these patients (78.6%) were reported to have no neurological sequelae. While data on choroid plexus AVMs remains limited, the available evidence suggests gross total resection of lesions in this location can be safely achieved with subsequent reduction in preoperative symptoms.

Incidental Massive Hydrocephalus Associated With an Unruptured Choroid Plexus Arteriovenous Malformation and Complete Agenesis of the Corpus Callosum Found in an Adult at Autopsy

Undiagnosed significant hydrocephalus is an uncommon finding at forensic autopsy as many cases present in life with complex neurological symptoms. We present a case of a 46-year-old man with no neurological deficits or history of head trauma that was incidentally found to have a massive hydrocephalus at autopsy. This was found to be associated with an unruptured arteriovenous malformation completely confined to the choroid plexus as well as complete agenesis of the corpus callosum. The arteriovenous malformation was found to form a calcified obstruction at the foramen of Monro analogous to a mass lesion, such as a colloid cyst of the third ventricle. The association of this malformation and agenesis of the corpus callosum has never been described. Histologic examination of the brain confirmed significant loss of white matter tracts and thinning of the cortical ribbon due to pressure atrophy of the ependymal lining without significant gliosis, cortical dysplasia, or evidence of other developmental malformations. Autopsy is a vital tool in the evaluation of such rare cases, enhances epidemiologic data, and increases the understanding of these pathophysiological associations.

Endoscope-assisted resection of cavernous angioma at the foramen of Monro: a case report

INTRODUCTION

Intraventricular cavernous angiomas are rare pathological entities, and those located at the foramen of Monro are even rarer. We herein present a case of cavernous angioma at the foramen of Monro that was successfully treated by neuroendoscope-assisted surgical removal, and review the relevant literature.

CASE PRESENTATION

A 65-year-old woman had experienced headache and vomiting for 10 days before admission to another hospital. Magnetic resonance imaging (MRI) showed a mass at the foramen of Monro, and obstructive hydrocephalus of both lateral ventricles. The patient was then referred to our hospital. Neurological examination on admission to our hospital showed memory disturbance (Mini-Mental State Examination 20/30) and wide-based gait. A cavernous angioma at the foramen of Monro was diagnosed based on the typical popcorn-like appearance of the lesion on MRI. The lesion was completely removed by neuroendoscope-assisted transcortical surgery with the Viewsite Brain Access System (Vycor Medical Inc., Boca Raton, FL), leading to a reduction in the size of the ventricles. The resected mass was histologically confirmed to be cavernous angioma. The patient's symptoms resolved immediately and there were no postoperative complications.

CONCLUSION

Minimally invasive neuroendoscope-assisted surgery was used to successfully treat a cavernous angioma at the foramen of Monro.

Huge familial colloid cyst of the third ventricle: An extraordinary presentation

Background:

Since the use of computed tomography and magnetic resonance imaging, colloid cysts (CCs) are discovered more frequently and subsequently their true incidence exceeds the numbers previously estimated. In 1986, the first familial case was reported in two identical twin brothers. To date, a total of 17 of these cases have been reported, all differing in the pattern of affected family members.

Case Description:

Here, we describe a unique presentation of a familial case and review the relevant literature on CCs and their natural history to improve our understanding of these cases.

Conclusion:

Familial CC can present in various patterns, sizes, and forms. A genetic factor is likely to be responsible in these cases, and further research is warranted to clarify this phenomenon.

A "pseudo-cavernoma" - an encapsulated hematoma of the choroid plexus

We present the first report of an intraventricular encapsulated hematoma, mimicking cavernous malformation on imaging and gross lesion appearance. A 47-year-old female on anticoagulation therapy for atrial fibrillation presented with left upper extremity apraxia, neglect, and mild gait imbalance. Her brain CT scan and MRI revealed multilobulated lesions involving the choroid plexus in the atria of both lateral ventricles. The intraoperative appearance was that of encapsulated mass, with blood clots at different stages of liquefaction and organization, all consistent with the gross appearance of a cavernous malformation. However, histopathologic examination demonstrated hematoma with components at different ages, and normal vessel infiltration without any hint of cavernous malformation histology, or underlying neoplasia. Encapsulated hematoma should be considered in the differential diagnosis of hemorrhagic intraventricular masses.

Enlarged thalamostriate vein causing unilateral Monro foramen obstruction. Case report

Causes of unilateral hydrocephalus resulting from an obstruction at the Monro foramen include foraminal atresia, tumors, gliosis, contralateral shunting, and infectious and inflammatory conditions. However, few reports in the literature cite vascular lesions as the cause of the obstruction. To their knowledge, the authors present the first report of unilateral hydrocephalus occurring due to an abnormally enlarged thalamostriate vein independent of an arteriovenous malformation or developmental venous angioma. The condition was treated successfully by endoscopic septum pellucidum fenestration. A 28-year-old man was referred for evaluation due to a 10-year history of chronic headaches that worsened in severity over the past year. A CT scan of the head revealed unilateral right ventricular dilation. Cranial MR imaging with and without contrast administration showed a dilated right thalamostriate-internal vein complex without any evidence of associated arteriovenous malformation or venous angioma. Endoscopic exploration of the right lateral ventricle showed an enlarged subependymal thalamostriate vein obstructing the Monro foramen. An endoscopic fenestration of the septum pellucidum was performed, resulting in alleviation of the patient's symptoms. Abnormally enlarged venous structures may cause obstructive unilateral hydrocephalus and can be a rare cause of chronic, intermittent headaches in adults. Endoscopic fenestration of the septum pellucidum is an effective treatment.

Intraventricular vascular malformations mimicking tumors: case reports and review of the literature

Vascular malformations of the ventricular system are rare, and their clinical and radiologic characteristics vary depending on the location of the lesions. Many types are described, but a comprehensive summary is lacking. Herein, we add two cases to the literature and review known types of ventricular vascular malformations. One case involved a 37-year-old woman who presented with headache due to hydrocephalus. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a lesion of the foramen of Monro. The other case involved a 7-year-old boy who had dizziness and headache due to hydrocephalus. CT and MRI demonstrated a lesion of the third ventricle. In both cases, the images mimicked those of tumors with or without bleeding. As a result, the malformations were misdiagnosed, though surgical treatment was successful. In both cases, the lesions were proven to be arteriovenous malformations on pathologic evaluation. Correct diagnosis of ventricular vascular malformations is sometimes difficult but essential for good treatment planning. Their incidence is low. However, their bleeding and rebleeding rate is high, and they commonly cause hydrocephalus. Treatment should be timely and based on the type of lesion and its presentation.

Angiographically occult vascular malformation of the third ventricle

Angiographically occult vascular malformations (AOVM) are cerebrovascular malformations that are not demonstrable on cerebral angiography. The majority of AOVMs located in the third ventricle are cavernous malformations. To the best of our knowledge an angiographically occult arteriovenous malformation (AOAVM) of the third ventricle has not been previously reported. We report an unusual vascular malformation of the third ventricle presenting with hydrocephalus due to mass effect, verified histopathologically as an AOAVM.

Endoscopic stent placement for treatment of secondary bilateral occlusion of the Monro foramina following endoscopic third ventriculostomy in a patient with aqueductal stenosis

✓ Nontumoral bilateral occlusion of the Monro foramina is a rare clinical condition. Treatment includes shunt placement, endoscopic procedures, or both. The authors describe the case of a 22-year-old woman who had previously undergone placement of a ventriculoperitoneal shunt via a right frontal approach for management of triventricular dilation due to aqueductal stenosis. Six years postoperatively she presented with right-sided slit-ventricle syndrome and stenosis of the right Monro foramen, which was treated with an endoscopic third ventriculostomy and fenestration of the septum pellucidum. Two years later she presented with bilateral lateral ventricular dilation. Inspection of the right lateral ventricle with a fiberscope revealed occlusion of the septum pellucidum fenestration; on observation, the right Monro foramen was covered by thick, tough granulation tissue and the left was occluded by thin membranous tissue. Repeated fenestration of the septum pellucidum and left Monro foraminoplasty were therefore performed by perforating this thin tissue. A stent was then introduced into the third ventricle via the right lateral ventricle, the fenestration in the septum pellucidum, and the left Monro foramen.

The authors note that fiberscopes are in general more maneuverable than rigid endoscopes and conclude that they are particularly useful for the treatment of this type of hydrocephalus.

Endoscopically-assisted resection of a choroid plexus vascular malformation traversing the cerebral aqueduct: technical case report

OBJECTIVE

We report a case of a choroid plexus vascular malformation of the cerebral aqueduct, third, and fourth ventricles of an adolescent female that was resected with endoscopic assistance.

CLINICAL PRESENTATION

A 14-year-old girl presented with a 1-week history of headaches and emesis. A noncontrasted computed tomographic scan of the head demonstrated enlarged lateral and third ventricles. Subsequent magnetic resonance imaging scans with and without contrast revealed an enhancing mass originating in the third ventricle, traversing the cerebral aqueduct, and terminating in the fourth ventricle.

RESULTS

We used a suboccipital approach to remove the vascular malformation after endoscopically disconnecting it from its feeding and draining vessels in the third ventricle. Total excision was performed. Postoperative magnetic resonance imaging scans and arteriograms confirmed complete resection of the vascular malformation.

CONCLUSION

Choroid plexus vascular malformations can exist intraventricularly and can be confused with a neoplasm. Resection of these intraventricular lesions can be performed with endoscopic assistance.

Cavernoma of the foramen of Monro

✓The authors report on a patient who presented with an intraventricular mass located at the level of the foramen of Monro. The clinical presentation and neuroimaging appearance of the mass led to an initial diagnosis of colloid cyst. A neuroendoscopic approach offered a direct view of the ventricular lesion, which was found to be a cavernous angioma partially occluding the foramen of Monro. The lesion was then removed using microsurgery. In this report the authors highlight possible pitfalls in the diagnosis of some lesions of the third ventricle, and the possible advantages of using a combined endoscopic and microsurgical technique when approaching such lesions.

Neuroendoscopic treatment of idiopathic occlusion of the foramen of Monro in adults--two case reports

Two adults presented with hydrocephalus due to idiopathic obstruction of the bilateral foramina of Monro, manifesting as clinical signs of chronically elevated intracranial pressure. No inflammation was present. The primary surgical treatment was neuroendoscopic reconstruction of the right foramen of Monro. A 37-year-old man had a spontaneous perforation of the septum pellucidum. The patient required a ventriculoperitoneal shunt, although postoperative ventriculography proved free passage of cerebrospinal fluid from the lateral ventricle into the third ventricle. A 62-year-old man underwent additional septostomy and third ventriculostomy, and the neuroendoscopic intervention relieved the presenting symptoms without additional treatment. The biopsy specimens showed no evidence of malignancy in either case. Neuroendoscopic intervention is an alternative treatment in the management of hydrocephalus due to idiopathic obstruction of the foramen of Monor. The procedure is less invasive than open microsurgical reconstruction and can even avoid ventriculoperitoneal or ventriculoatrial shunting.

[Endoscopic fenestration as a treatment for asymmetrical hydrocephalus due to obstruction of the foramen of Monro]

Unilateral dilatation of the lateral ventricle is a rare condition. The most common causes are tumors of the lateral ventricles or in the area of the third ventricle, acute or chronic inflammatory gliosis, cysticercosis or congenital atresia of the foramen of Monro. We report a case of asymmetrical dilatation of the lateral ventricle in an adult patient presenting with a raised intracranial pressure syndrome caused by narrowing of the foramen of Monro which was occluded by a thin membrane. The patient underwent successful endoscopic fenestration of the Foramen of Monro.

Arteriovenous malformation of the choroid plexus

A case of a 55-year-old female with arteriovenous malformation (AVM) of the choroid plexus within the right ventricle is reported. Arteriovenous malformation of the choroid plexus is a rare occurrence. The MR findings of this malformation are discussed.

Diagnosis and treatment of colloid cysts of the third ventricle by stereotactic drainage. Report on eleven cases

Between December 1979 and September 1986, 11 patients with colloid cysts of the third ventricle were operated on by a stereotactic procedure with Talairach's system. Stereoscopic angiography and ventriculographic study allowed for a percutaneous (twist-drill hole diameter: 2.5 mm) stereotactic aspiration of the cysts. The operations were successful, and there were no intraoperative or postoperative mortalities but just mild transient morbidity in three cases. Six cysts were evacuated completely, and five only partially. The mean residual volume was 19% of the initial one. Clinical and anatomical results are presented, and the advantages of this stereotactic procedure are discussed.

Congenital constriction of the foramen of Monro

We report two cases of hydrocephalus in adults. The radiological investigations and direct inspection during surgery in one of the cases indicate that the hydrocephalus is caused in both cases by a benign stricture in the region of the foramen of Monro and that this constriction is congenital. This origin of hydrocephalus has not been reported previously in adults.

Cryptic arteriovenous malformation of the choroid plexus of the third ventricle

A patient with a history of subarachnoid hemorrhage is reported. CT scan evidenced a high-density, round lesion in the anterior part of the third ventricle. A full angiographic study demonstrated no vascular malformation. After removal of a circumscribed hematoma in the anterior part of the third ventricle, an arteriovenous malformation of the choroid plexus was excised.

Cryptic vascular malformation of the choroid plexus

A 45-year-old man and a 47-year-old woman with cryptic vascular malformations of the choroid plexus in the lateral ventricle are reported. Each patient had an intraventricular hematoma, located in the right trigone and in the anterior part of the left lateral ventricle, respectively. The vascular lesion of one patient was angiographically visualized as find abnormal vessels communicating with the right anterior choroidal artery; in the other, angiography did not reveal the lesion. In the former patient, histological examination of the excised specimen led to a diagnosis of arteriovenous malformation; in the latter, a diagnosis of venous malformation was made. Both patients were successfully treated surgically.