Sudden intraaqueductal dislocation of a third ventricle ependymoma causing acute decompensation of hydrocephalus

Successful Treatment of Pure Aqueductal Pilomyxoid Astrocytoma and Arrested Hydrocephalus With Endoscopic Tumor Resection Followed by Chemotherapy: A Case Report and Technical Considerations

BACKGROUND AND IMPORTANCE

Pure aqueductal tumors are extremely rare and may lead to death, regardless of histopathology. We report the first case of pure aqueductal pilomyxoid astrocytoma in an adult woman with arrested hydrocephalus. Endoscopic tumor resection for securing aqueductal patency followed by chemotherapy allowed control of both the tumor and the hydrocephalus.

CLINICAL PRESENTATION

A 20-year-old woman presented with mild cognitive dysfunction and marked ventricular dilatation. She had no preoperative symptoms of intracranial hypertension, and her head circumference was more than 2 SDs above the 98th percentile. The aqueduct of Sylvius was entirely occupied by a neoplastic lesion with 2 periventricular nodules at the wall of the third ventricle and anterior horn of the right lateral ventricle. She was treated successfully with endoscopic tumor resection followed by chemotherapy, and the patency of the aqueduct of Sylvius was secured throughout the duration of treatment.

CONCLUSION

Pure aqueductal tumors may be an appropriate indication for endoscopic tumor resection to secure the aqueductal patency of cerebrospinal fluid. This case demonstrates the surgical technique of a combined rigid-flexible endoscopic transforaminal approach, which was a useful surgical intervention for the management of this patient.

Microsurgical techniques for achieving gross total resection of ependymomas of the fourth ventricle

Ependymomas arising from the ventricular surface present a major challenge to achieving a complete operative extirpation when located in the fourth ventricle given the presence of significant adherence to the floor of the same. Overzealous dissection and removal of a tumor from this zone may precipitate potentially catastrophic neurological deficits attributable to cranial nucleopathies and cranial neuropathies. Consequently, the classic neurosurgical teaching has advised attempted gross total resection, leaving adherent residual in the floor of the fourth ventricle, in order to prevent the development of major cranial nucleopathies and cranial neuropathies. Following surgical tumoral extirpation, residual tumor is adjuvantly stereotactically irradiated. Authors have consequently developed novel neurophysiologically guided microsurgical techniques designed to remove adherent tumor from the fourth ventricular floor. These strategies have successfully and consistently facilitated gross total resection and improved clinical outcomes in patients harboring ependymomas of the fourth ventricle. We discuss and evaluate the innovation in microsurgical strategies developed to achieve complete operative extirpation of tumoral adherence to the floor of the fourth ventricle.

A Novel Dissection Method Using a Flexible Neuroendoscope for Resection of Tumors Around the Aqueduct of Sylvius

BACKGROUND

Flexible endoscopes have both a wide range of movement and a wide field of view and are therefore widely used for endoscopic third ventriculostomy and biopsy. However, tumor resection around the aqueduct of Sylvius using flexible endoscopes has scarcely been reported.

CASE DESCRIPTION

We report 2 cases of tumor resection around the aqueduct of Sylvius. The first case is a 38-year-old man presenting with progressive headache, nausea, and diplopia. Magnetic resonance imaging (MRI) revealed a 1.4 cm nonenhancing mass at the entry of the aqueduct of Sylvius and occlusive hydrocephalus. We performed tumor resection and endoscopic third ventriculostomy (ETV) simultaneously. His symptoms disappeared after the operation. Final pathologic diagnosis was ancient schwannoma. The second case is a 78-year-old woman presenting with progressive disturbance of consciousness (coma). MRI showed 0.7 cm nonenhancing mass at the entry of the aqueduct of Sylvius and occlusive hydrocephalus. We performed tumor resection and ETV similarly. Her consciousness improved after the operation. Final tumor diagnosis was cavernous malformation. In both cases there was no additional neurologic deficit after the surgery.

CONCLUSIONS

By using a flexible endoscope for tumor dissection, resection of a tumor without a neck, which cannot be removed through aspiration alone, becomes possible. To our knowledge, the presented cases are the first to describe the effectiveness of complete resection of a tumor in the third ventricle using flexible endoscopy.

Neuroendoscopic management of posterior third ventricle ependymoma with intraaqueductal and fourth ventricle extension: a case report and review of the literature

INTRODUCTION

Posterior third ventricle ependymomas with intraaqueductal extension are relatively infrequent lesions. Its surgical management represents a formidable technical challenge and includes a wide variety of approaches. Minimally invasive surgery including the endoscopic management can play a crucial role to obtain an optimal clinical outcome.

PATIENTS AND METHODS

We report the clinical outcome of an 11-year-old female patient with a 6-year history of recurrent episodes of headache and vomiting. On brain MRI a posterior third ventricle lesion with extension to the aqueduct of Sylvius and fourth ventricle, and associated hydrocephalus was observed.

RESULTS

Our management of the lesion included a two-step endoscopic surgery: first an anterior third ventriculostomy and biopsy of the lesion that was reported to be a low-grade ependymoma, and posteriorly an endoscopic-assisted resection of the lesion. Clinical outcome was optimal without neurological sequelae. The postoperative MRI showed a thickened ependymal area on the tumor base of implantation. It was considered to be a remnant of the lesion and subsequently treated with radiotherapy.

CONCLUSION

Posterior third ventricle ependymomas with intraaqueductal extension can be endoscopically managed to obtain a successful outcome.

Natural history of colloid cysts of the third ventricle

OBJECTIVE Colloid cysts are rare, histologically benign lesions that may result in obstructive hydrocephalus and death. Understanding the natural history of colloid cysts has been challenging given their low incidence and the small number of cases in most reported series. This has complicated efforts to establish reliable prognostic factors and surgical indications, particularly for asymptomatic patients with incidental lesions. Risk factors for obstructive hydrocephalus in the setting of colloid cysts remain poorly defined, and there are no grading scales on which to develop standard management strategies. METHODS The authors performed a single-center retrospective review of all cases of colloid cysts of the third ventricle treated over nearly 2 decades at Washington University. Univariate analysis was used to identify clinical, imaging, and anatomical factors associated with 2 outcome variables: symptomatic clinical status and presentation with obstructive hydrocephalus. A risk-prediction model was defined using bootstrapped logistic regression. Predictive factors were then combined into a simple 5-point clinical scale referred to as the Colloid Cyst Risk Score (CCRS), and this was evaluated with receiver-operator characteristics. RESULTS The study included 163 colloid cysts, more than half of which were discovered incidentally. More than half of the incidental cysts (58%) were followed with surveillance neuroimaging (mean follow-up 5.1 years). Five patients with incidental cysts (8.8%) progressed and underwent resection. No patient with an incidental, asymptomatic colloid cyst experienced acute obstructive hydrocephalus or sudden neurological deterioration in the absence of antecedent trauma. Nearly half (46.2%) of symptomatic patients presented with hydrocephalus. Eight patients (12.3%) presented acutely, and there were 2 deaths due to obstructive hydrocephalus and herniation. The authors identified several factors that were strongly correlated with the 2 outcome variables and defined third ventricle risk zones where colloid cysts can cause obstructive hydrocephalus. No patient with a lesion outside these risk zones presented with obstructive hydrocephalus. The CCRS had significant predictive capacity for symptomatic clinical status (area under the curve [AUC] 0.917) and obstructive hydrocephalus (AUC 0.845). A CCRS ≥ 4 was significantly associated with obstructive hydrocephalus (p < 0.0001, RR 19.4). CONCLUSIONS Patients with incidentally discovered colloid cysts can experience both lesion enlargement and symptom progression or less commonly, contraction and symptom regression. Incidental lesions rarely cause acute obstructive hydrocephalus or sudden neurological deterioration in the absence of antecedent trauma. Nearly one-half of patients with symptomatic colloid cysts present with obstructive hydrocephalus, which has an associated 3.1% risk of death. The CCRS is a simple 5-point clinical tool that can be used to identify symptomatic lesions and stratify the risk of obstructive hydrocephalus. External validation of the CCRS will be necessary before objective surgical indications can be established. Surgical intervention should be considered for all patients with CCRS ≥ 4, as they represent the high-risk subgroup.

The Evaluation and Management of Pediatric Syncope

Syncope is a common problem in children and adolescents. It is typically caused by benign neurally mediated hypotension, but other, more concerning, etiologies of syncope must be considered. In most instances, the underlying cause of syncope in the pediatric patient can be determined by obtaining a thorough history and physical examination. Attention to the cardiac, neurological, and psychological history and examination can rule out more rare causes of loss of consciousness. Most individuals with neurally mediated hypotension can be treated with lifestyle measures including aggressive hydration, dietary salt, and an exercise program. In instances where lifestyle modification fails, medications may offer symptomatic improvement.

Anaplastic ependymoma of the third ventricle

Supratentorial ependymomas are rare, especially in the third ventricle. We report the case of an ependymoma of the posterior third ventricle that was endoscopically removed just by aspiration through a flexible scope. Histologically, beside the typical pattern of growth with perivascular pseudorosettes, the tumor featured hypercellular areas with more than 10 mitoses per 10 high-power fields, consistent with grade III-anaplastic tumor. A few months later, a second neuroendoscopy offered the unique chance to appreciate the total absence of tumor tissue and the restored anatomy. However, consistently with the high grade, the tumor recurred in two different locations including the endoscopic trajectory, and spread through the cerebrospinal fluid. The patient underwent a second resective surgery and radiosurgery. Despite a cycle of chemotherapy, multiple lesions both in the ventricular system and at the level of cauda equina appeared 12 months later. A comprehensive review of intraventricular anaplastic ependymomas is also provided.

Neuroendoscopic aspiration of tumors in the posterior third ventricle and aqueduct lumen: a technical update

BACKGROUND

Small soft ventricular tumors are good candidates for complete removal by a purely endoscopic technique. This approach is particularly interesting for lesions located in the posterior third ventricle and aqueductal lumen.

METHODS

We present our method of endoscospic aspiration through direct contact between the tumor and the working channel of a flexible scope.

RESULTS

Aspiration without the intermediate use of cannulas is safe and has proved to be effective in the apparently total or partial removal of three soft tumors of different pathologies located in the third ventricle or aqueductal lumen. In one case, a second neuroendoscopy a few months later to repeat endoscopic third ventriculostomy (ETV) offered a unique opportunity to observe the absence of the tumor and the restored anatomy.

CONCLUSIONS

Neuroendoscopy provides a safe, effective way to radically resect small soft tumors in these troublesome locations and can be a valuable alternative to microsurgery.