Lateral-type posterior fossa ependymomas in pediatric patients: a national collaborative study.

PURPOSE: To review a multicentric series of lateral-type posterior fossa ependymomas operated in the last ten years and to analyze the factors related to clinical evolution and tumor survival. METHODS: Descriptive, retrospective study. Active members of the Spanish Society of Pediatric Neurosurgery were invited to participate in this multicentric study. Clinical and radiological data were incorporated to an open database. The role of histologic grade, grade of resection, postoperative morbidities, and clinical follow-up was evaluated through bivariate associations (chi-square), Kaplan-Meier's curves (log-rank test), and multivariate analysis (binary logistic regression). RESULTS: Fourteen centers entered the study, and 25 cases with a minimum follow-up of 6 months were included. There were 13 boys and 12 girls with a mean age close to 3 years. Mean tumor volume at diagnosis was over 60 cc. A complete resection was achieved in 8 patients and a near-total resection in 5 cases. Fifteen tumors were diagnosed as ependymoma grade 2 and ten as ependymoma grade 3. Major morbidity occurred postoperatively in 14 patients but was resolved in twelve within 6 months. There were six cases of death and 11 cases of tumor progression along the observation period. Mean follow-up was 44.8 months. Major morbidity was significantly associated with histologic grade but not with the degree of resection. Overall and progression-free survival were significantly associated with complete surgical resection. At the last follow-up, 16 patients carried a normal life, and three displayed a mild restriction according to Lansky's scale. CONCLUSIONS: Lateral-type posterior fossa ependymomas constitute a specific pathologic and clinical tumor subtype with bad prognosis. Gross total resection is the goal of surgical treatment, for it significantly improves prognosis with no additional morbidity. Neurological deficits associated to lower cranial nerve dysfunction are common, but most are transient. Deeper genetic characterization of these tumors may identify risk factors that guide new treatments and stratification of adjuvant therapies.

Gangliogliomas in the pediatric population.

BACKGROUND: Gangliogliomas are neoplastic lesions composed by a mixed population of neoplastic glial and dysplastic neural cells. They represent around 5% of all CNS tumors in the pediatric population. These usually are well-differentiated, slow-growing tumors, meaning that complete resection could cure most of these patients. Although most lesions remain stable over time after incomplete resection, some patients develop progression of the residual lesions: the optimal approach to treat these tumors is still to be defined. METHODS: This is a retrospective study in which we obtained data from medical records of pediatric patients who had a histological diagnosis of ganglioglioma following surgical treatment at a single center between 2001 and 2020. RESULTS: We included 17 pediatric subjects with gangliogliomas. The median age at diagnosis was 6.7 years, and the median follow-up duration was 60 months. The most common clinical presentation was epileptic seizures (41.1%). Hydrocephalus was present in 29.4% of cases. 52.9% of tumors involved exclusively the cerebral hemispheres, with the temporal lobe being the most affected location. Gross total tumor resection (GTR) was accomplished in 47% of all cases and in 75% of hemispheric tumors. Of patients, 33% in whom GTR could not be achieved showed progression of the residual tumor. BRAF V600E mutation was present in 44.4% of cases. CONCLUSION: Gangliogliomas are typically grade I tumors that occasionally affect children. They classically localize in the cerebral hemisphere but may involve deep structures like the basal ganglia, brain stem, and cerebellum, which seems to be particularly frequent in the pediatric population, implying further challenge to achieve adequate oncological control with surgery as the only treatment modality. Although most cases in which GTR could not be performed remained stable over the follow-up, significant progression of the tumor remains was observed in some patients. BRAF inhibitors should be considered as a feasible treatment option in this setting.

Laparoscopy-assisted placement of a ventriculobiliary shunt: a technical note.

PURPOSE: Hydrocephalus is a common condition in pediatric neurosurgeon's clinical practice. Peritoneal and atrial shunting is the treatment of choice in the immense majority of patients. Sometimes, there are complex cases that may need innovative solutions in order to implant the distal catheter of the shunt: in these situations, the gallbladder is a well-described option and it can be safely used. METHODS: We report the case of a 4-month-old baby with a wide optic-chiasmal hypothalamic glioma generating hydrocephalus with high protein values in CSF. Ventriculobiliary shunting was decided, and the distal catheter was directed by the assistance of laparoscopic surgery. RESULTS: The outcome was satisfactory. CONCLUSIONS: As far as we know, laparoscopic placement of a distal catheter in the gallbladder has not been described in the literature; herein, we describe the tenets and the technical tips of this approach.

Full endoscopic endonasal transclival approach: meningioma attached to the ventral surface of the brainstem.

BACKGROUND: Intracranial meningiomas without dural attachment (MWODA) are rare entities. We present the first case published, to the best of our knowledge, regarding a MWODA attached to the ventral surface of the brainstem. This location makes the patient subsidiary to treatment through an expanded endonasal transclival approach. CLINICAL PRESENTATION: A 16-year-old female with suspected diagnosis of recurrence of a clear cell meningioma (CCM) at a distance from the initial lesion, located on the premedullary cistern. The patient underwent a pure endoscopic low transclival approach. The attachment to the ventral surface of the brainstem was confirmed intraoperatively. Postoperative MRI confirmed gross total resection and treatment was complemented with adjuvant fractionated stereotactic radiotherapy. No complications related to the procedure were observed. CONCLUSION: MWODA may appear attached to the ventral brainstem. The expanded endonasal approach to the clivus provides a critical anatomical advantage in the treatment of medial lesions, even ventral meningiomas, to the lower cranial nerves. Reconstruction principles must be strictly respected to reduce complications.

Lateral-type posterior fossa ependymomas in pediatric population.

BACKGROUND: Lateral-type posterior fossa ependymomas are a well-defined subtype of tumours both clinically and pathologically, with a poor prognosis. Their incidence is low and surgical management is challenging. The objective of the present work is to review our series of lateral-tye posterior fossa ependymomas and compare our results with those of previous series. METHODS: Among 30 cases of ependymoma operated in our paediatric department in the last ten years, we identified seven cases of lateral-type posterior fossa ependymomas. We then performed a retrospective, descriptive study. RESULTS: Mean age of our patients was 3.75 years. 6 cases presented with hydrocephalus. Mean tumour volume at diagnosis was 61 cc. A complete resection was achieved in six cases and a near-total resection in one patient. 5 patients transiently required a gastrostomy and a tracheostomy. Mean follow-up was 58 months. One case progressed along this period and eventually died. 4 cases of hydrocephalus required a ventriculoperitoneal CSF shunt and two were managed with a third ventriculostomy. At last follow-up 4 patients carried a normal life and two displayed a mild restriction according to Lansky´s scale. CONCLUSIONS: The aim of surgical treatment in lateral-type posterior fossa ependymomas is complete resection. Neurological deficits associated to lower cranial nerve dysfunction are common but transient. Deeper genetic characterization of these tumours may identify risk factors that guide stratification of adjuvant therapies.

Primary extraosseous intradural spinal Ewing's sarcoma: report of two cases.

Two cases of primary extraosseous intradural spinal Ewing's sarcoma are reported with a review of the current literature. This rare neoplasm shares features with cerebral primitive neuroectodermal tumors, complicating a correct diagnosis. Gross total resection seems to be the main treatment, although adjuvant therapies could improve the prognosis. In case 1, a 56-year-old man presented with cauda equina syndrome. MRI showed an intradural tumor from L4 to S2. An emergency laminectomy was performed with gross total resection of a hemorrhagic tumor, followed by adjuvant treatment. In the second case, a 25-year-old female developed leg and lumbar pain. MRI study identified a homogeneously enhancing intradural mass at the L2-L3 level. A laminoplasty was performed, followed by tumor resection; no adjuvant treatment was administered afterwards. Immunohistochemical workup confirmed the diagnosis of Ewing's sarcoma in both cases.

[Transpterygoid expanded endonasal approach in fibrous dysplasia of the skull base: case report and technical note]. / Abordaje endonasal expandido transpterigoideo en la displasia fibrosa de base de cráneo: caso clínico y nota técnica.

INTRODUCTION: Expanded endonasal approaches (EEA) are becoming a first-level technique for the treatment of skull base pathologies. In some cases, the endoscopic procedures make it possible to dissect structures manipulated with greater difficulty in the classic approaches. We report a full endoscopic transpterygoid EEA for the treatment of a fibrous dysplasia (FD) of the skull base. In addition, we reviewed the English literature available on FD and transpterygoid EEA, establishing an exact surgical technique and showing our intraoperative experience. CASE REPORT: A 42-year-old male with right sixth cranial nerve palsy. Cranial MRI and CT showed a central skull base lesion with diagnostic suspicion of FD. Patient underwent a full endoscopic transpterygoid EEA, achieving a wide skull base neurovascular decompression. Neuronavigation and the vidian canal landmark resulted mandatory during intraoperative procedure. DISCUSSION: The transpterygoid EEA is a safe technique consistently supported in the literature. It may reduce the morbidity associated to the classic transcranial approaches, since it permits maximum resection with minimum craniofacial distortion. The vidian hole and canal are the landmarks used to locate and avoid injury to the lacerum segment of the carotid injury. The surgical treatment indication in FD cases must be established in symptomatic patients. CONCLUSION: Transpterygoid EEA for treatment of FD of the skull base is a safe and effective procedure, thanks to the guide that the vidian canal provides in finding the lacerum segment of the carotid artery.

Full endoscopic endonasal extreme far-medial approach: Eustachian tube transposition.

The complex anatomical relationships within the skull base have been described from an endoscopic point of view. However, systematic surgical, not just anatomical, management of the eustachian tube (ET) and the approach to the styloid and parapharyngeal spaces have not yet been described. The authors describe the full endoscopic endonasal extreme far-medial approach used in their surgical practice and show how they applied it to a case. To the authors' knowledge, from a strictly surgical viewpoint, this work is the first to describe a fundamental endonasal approach to the inferior clivus, the condylar and tubercular compartments, the prestyloid and poststyloid spaces, and ET transposition to expose the aforementioned structures without disrupting the ET. For lesions with mediolateral growth patterns, the authors consider the extreme far-medial approach to be superior to the pure transmaxillary approach. Additional cases and more evidence are needed to refine this surgical technique.