<b><i>Introduction:</i></b> Pilocytic astrocytomas (PA) are a common, benign childhood tumor known for their slow growth rates and excellent prognosis. The aim of our study was to characterize patient, tumor, and imaging-related risk factors for recurrence and progression of disease. <b><i>Methods:</i></b> We identified 116 patients with PA who underwent surgery at our institution between 2000 and 2015. Data were collected retrospectively from the clinical charts. <b><i>Results:</i></b> The mean age at resection was 7 ± 5 years (range 0.5–31) and mean follow-up was 6 ± 3 years. Initial resection was complete in 33 patients (29%), subtotal in 78 patients (67%), and biopsy in 5 patients (4%). A total of 45/116 (40%) patients experienced either recurrence or progression after initial resection with a mean time to recurrence or progression of 2.2 years. Bivariate analysis identified subtotal resection, tumor location, age at diagnosis, and imaging features (i.e., T2 invasion, exophytic component, hemorrhage, and solid tumors) as factors significantly associated with recurrence or progression (<i>p</i> &#x3c; 0.05). Conversely, PAs that were completely resected, predominately cystic, and located in the cerebellum were significantly associated with no recurrence or progression (<i>p</i> &#x3c; 0.05). Multivariate regression analysis narrowed down 4 robust risk factors: extent of resection, T2 invasion, predominantly solid lesions, and presence of an exophytic component (<i>p</i> &#x3c; 0.05). <b><i>Conclusion:</i></b> Total surgical removal of PA has been the most important prognostic factor for the clinical course of PA. Our study reveals additional risk factors for the recurrence or progression of disease: tumor invasion, solid composition, and tumors with an exophytic component.

This study reveals 5 risk factors for postoperative seizures after resection of supratentorial tumors. These factors should be considered in postoperative management of these patients.

OBJECTIVE Facial palsy can be caused by masses within the posterior fossa and is a known risk of surgery for tumor resection. Although well documented in the adult literature, postoperative facial weakness after posterior fossa tumor resection in pediatric patients has not been well studied. The objective of this work was to determine the incidence of postoperative facial palsy after tumor surgery, and to investigate clinical and radiographic risk factors. METHODS A retrospective analysis was conducted at a single large pediatric hospital. Clinical, radiographic, and histological data were examined in children who were surgically treated for posterior fossa tumors between May 1, 1994, and June 1, 2011. The incidence of postoperative facial weakness was documented. A multivariate logistic regression model was used to analyze the predictive ability of clinicoradiological variables for facial weakness. RESULTS A total of 163 patients were included in this study. The average age at surgery was 7.4 ± 4.7 years, and tumor pathologies included astrocytoma (44%), medulloblastoma (36%), and ependymoma (20%). The lesions of 27 patients (17%) were considered high grade in nature. Thirteen patients (8%) exhibited preoperative symptoms of facial palsy. The overall incidence of postoperative facial palsy was 26% (43 patients), and the incidence of new postoperative facial palsy in patients without preoperative facial weakness was 20% (30 patients). The presence of a preoperative facial palsy had a large and significant effect in univariate analysis (OR 11.82, 95% CI 3.07–45.44, p < 0.01). Multivariate logistic regression identified recurrent operation (OR 4.45, 95% CI 1.49–13.30, p = 0.01) and other preoperative cranial nerve palsy (CNP; OR 3.01, 95% CI 1.24–7.29, p = 0.02) as significant risk factors for postoperative facial weakness. CONCLUSIONS Facial palsy is a risk during surgical resection of posterior fossa brain tumors in the pediatric population. The study results suggest that the incidence of new postoperative facial palsy can be as high as 20%. The presence of preoperative facial palsy, an operation for recurrent tumor, and the presence of other preoperative CNPs were found to be significant risk factors for postoperative facial weakness.