Survival analysis and prognostic factors in posterior fossa ependymomas in children and adolescents.

OBJECTIVE: In this study, the authors aimed to analyze the overall survival (OS) and progression-free survival (PFS) of patients younger than 18 years of age who were diagnosed with posterior fossa ependymomas, and to identify prognostic factors such as the degree of resection, tumor topography, and involvement of the lesion in the hindbrain. METHODS: The authors performed a retrospective cohort study of patients younger than 18 years of age, treated beginning in 2000, with a diagnosis of posterior fossa ependymoma. Ependymomas were separated into three groups: tumors restricted to the fourth ventricle, tumors inside the fourth ventricle and exiting from the foramen of Luschka, and tumors inside the fourth ventricle and completely surrounding the hindbrain. Furthermore, the tumors were classified by molecular group using the staining method for H3K27me3. Statistical analysis was performed using Kaplan-Meier survival curves, with p < 0.05 considered statistically significant. RESULTS: Of 1693 patients who underwent surgical treatment between January 2000 and May 2021, 55 patients who met the inclusion criteria were included. The median age at diagnosis was 2.98 years. The median OS was 44 months, and the survival rates at 1, 5, and 10 years were 92.5%, 49.1%, and 38.3%, respectively. The cases were assigned to two posterior fossa ependymoma molecular groups: 35 (63.6%) cases to group A and 8 (14.5%) to group B. The median ages in groups A and B were 2.94 and 2.85 years and the median OS values were 44 and 38 months, respectively (p = 0.9245). Statistical analysis was performed on multiple variables, including age, sex, histological grade, Ki-67 expression, tumor volume, extent of resection, and adjuvant therapies. The median PFS of patients with dorsal-only involvement was 28 months; for dorsolateral involvement, it was 15 months; and for total involvement, it was 9.5 months (p = 0.0464). No statistically significant difference was found for OS. There was a statistically significant difference between the proportion of patients in whom gross-total resection was achieved in the dorsal-only involvement group (73.1%, 19/26) and those in the total involvement group (0%, 0/6) (p = 0.0019). CONCLUSIONS: This study confirmed that the extent of resection has an impact on OS and PFS. The authors found that adjuvant radiotherapy resulted in a higher OS but did not prevent progression, that the pattern of involvement of the brainstem in the tumor at diagnosis could elicit important information regarding the patient's prognosis regarding PFS, and that the total involvement of the rhombencephalon impaired the gross-total resection of these tumors.

Glioependymal cyst on the third cranial nerve: case report.

Glioependymal cysts are a rare, congenital, and benign condition. The authors report a case of a 2-year-old female patient who presented with a large exophytic glioependymal cyst located in the left cerebral peduncle, which began with a history of deteriorating function of the left third cranial nerve (CN III). A left 3-piece fronto-orbitozygomatic approach and a microsurgical complete excision of the cyst were performed without complications by accessing the midbrain through the perioculomotor entry zone. The patient's CN III function completely recovered after 3 months. Because there are currently no widely approved and used classification systems for these cysts, their reporting, naming, and classification are quite confusing in the literature. Thus, their origin, classification, and most common locations warrant further investigation. In addition to reporting this case, the authors present their review of the literature.

New therapeutic target for pediatric anaplastic ependymoma control: study of anti-tumor activity by a Kunitz-type molecule, Amblyomin-X.

EPNs comprise a heterogeneous group of neuroepithelial tumors, accounting for about 10% of all intracranial tumors in children and up to 30% of brain tumors in those younger than 3 years. Actually, the pattern therapy for low-grade EPNs includes complete surgical resection followed by radiation therapy. Total surgical excision is often not possible due to tumor location. The aim of this study was to evaluate, for the first time, the anti-tumor activity of Amblyomin-X in 4 primary cultures derived from pediatric anaplastic posterior fossa EPN, Group A (anaplastic, WHO grade III) and one primary culture of a high grade neuroepithelial tumor with MN1 alteration, which was initially misdiagnosed as EPN: i) by in vitro assays: comparisons of temozolomide and cisplatin; ii) by intracranial xenograft model. Amblyomin-X was able to induce cell death in EPN cells in a more significant percentage compared to cisplatin. The cytotoxic effects of Amblyomin-X were not detected on hFSCs used as control, as opposed to cisplatin-treatment, which promoted a substantial effect in the hAFSCs viability. TEM analysis showed ultrastructural alterations related to the process of cell death: mitochondrial degeneration, autophagosomes and aggregate-like structures. MRI and histopathological analyzes demonstrated significant tumor mass regression. Our results suggest that Amblyomin-X has a selective effect on tumor cells by inducing apoptotic cell death and may be a therapeutic option for Group AEPNs.