Complications following resection of primary and recurrent pediatric posterior fossa ependymoma

OBJECTIVE

Extent of resection (EOR) is the most important modifiable prognostic variable for pediatric patients with posterior fossa ependymoma. An understanding of primary and recurrent ependymoma complications is essential to inform clinical decision-making for providers, patients, and families. In this study, the authors characterize postsurgical complications following resection of primary and recurrent pediatric posterior fossa ependymoma in a molecularly defined cohort.

METHODS

The authors conducted a 20-year retrospective single-center review of pediatric patients undergoing resection of posterior fossa ependymoma at the Hospital for Sick Children in Toronto, Canada. Complications were dichotomized into major and minor groups; EOR was compared across complication categories. The association between complication occurrence with length of stay (LOS) and mortality was also assessed using multivariable regressions.

RESULTS

There were 60 patients with primary resection included, 41 (68%) of whom were alive at the time of data collection. Gross-total resection was achieved in 33 (58%) of 57 patients at primary resection. There were no 30-day mortality events following primary and recurrent ependymoma resection. Following primary resection, 6 patients (10%) had posterior fossa syndrome (PFS) and 36 (60%) developed cranial neuropathies, 56% of which recovered within 1 year. One patient (1.7%) required a tracheostomy and 9 patients (15%) required gastrostomy tubes. There were 14 ventriculoperitoneal shunts (23%) inserted for postoperative hydrocephalus. Among recurrent cases, there were 48 recurrent resections performed in 24 patients. Complications included new cranial neuropathy in 10 patients (21%), of which 5 neuropathies resolved within 1 year. There were no cases of PFS following resection of recurrent ependymoma. Gastrostomy tube insertion was required in 3 patients (6.3%), and 1 patient (2.0%) required a tracheostomy. Given the differences in the location of tumor recurrence, a direct comparison between primary and recurrent resection complications was not feasible. Following multivariate analysis adjusting for sex, age, molecular status, and EOR, occurrence of major complications was found to be associated with prolonged LOS but not mortality.

CONCLUSIONS

These results detail the spectrum of postsurgical morbidity following primary and recurrent posterior fossa ependymoma resection. The crude complication rate following resection of infratentorial recurrent ependymoma was lower than that of primary ependymoma, although a statistical comparison revealed no significant differences between the groups. These results should serve to inform providers of the morbidity profile following surgical management of posterior fossa ependymoma and inform perioperative counseling of patients and their families.

Radiation-induced Supratentorial Osteosarcoma Following Curative Treatment of Infratentorial Ependymoma in a Child

The development of secondary neoplasms following therapeutic cranial irradiation is rare and quite often lethal. Meningiomas, sarcomas, and high-grade gliomas are the most common tumors that manifest as a result of radiation therapy. We report the case of an 11-year-old child who presented with symptoms of supratentorial space-occupying lesion 7 years after curative surgery and cranial irradiation for a posterior fossa ependymoma. Magnetic resonance imaging of the brain revealed a right-sided temporoparietal dural-based contrast-enhancing lesion with evidence of overlying bone and skin involvement. The histological report of ependymoma from the previous surgery led us to suspect that we were dealing with a recurrence until the histopathology of the second surgery revealed highly malignant osteosarcoma. The child recovered fully and underwent chemotherapy, but ultimately succumbed to the disease. We report this case to highlight the importance of recognizing these neoplasms and to review its management.

CN133, a Novel Brain-Penetrating Histone Deacetylase Inhibitor, Hampers Tumor Growth in Patient-Derived Pediatric Posterior Fossa Ependymoma Models

Pediatric ependymoma (EPN) is a highly aggressive tumor of the central nervous system that remains incurable in 40% of cases. In children, the majority of cases develop in the posterior fossa and can be classified into two distinct molecular entities: EPN posterior fossa A (PF-EPN-A) and EPN posterior fossa B (PF-EPN-B). Patients with PF-EPN-A have poor outcome and are in demand of new therapies. In general, PF-EPN-A tumors show a balanced chromosome copy number profile and have no recurrent somatic nucleotide variants. However, these tumors present abundant epigenetic deregulations, thereby suggesting that epigenetic therapies could provide new opportunities for PF-EPN-A patients. In vitro epigenetic drug screening of 11 compounds showed that histone deacetylase inhibitors (HDACi) had the highest anti-proliferative activity in two PF-EPN-A patient-derived cell lines. Further screening of 5 new brain-penetrating HDACi showed that CN133 induced apoptosis in vitro, reduced tumor growth in vivo and significantly extended the survival of mice with orthotopically-implanted EPN tumors by modulation of the unfolded protein response, PI3K/Akt/mTOR signaling, and apoptotic pathways among others. In summary, our results provide solid preclinical evidence for the use of CN133 as a new therapeutic agent against PF-EPN-A tumors.

Posterior fossa ependymoma in childhood: 60 years event-free survival after partial resection—a case report

A 13-year-old boy with severe clinical symptoms and signs underwent surgery for a posterior fossa ependymoma in 1954. The tumor was adjacent to the floor of the fourth ventricle, and surgery was complicated by profound bleeding. Therefore, only a partial resection was performed. Postoperative radiotherapy was given to the posterior fossa. The recovery was uneventful, and he has been in full-time work until the age of 62 years and is now 74 years old. Repeated MRI scans demonstrate a stable residual fourth ventricular tumor.