Posterior Fossa Ependymomas: Report of 30 Cases and Review of the Literature

Abstract

Thirty patients with histologically confirmed posterior fossa ependymomas operated on between January 1976 and December 1988 were reviewed. The median age was 44 years (range, 1-69 yr). There were 7 children (aged 5 yr or younger) and 23 adults (aged 16 yr or older). There were 18 female patients and 12 male patients. Headache, nausea and vomiting, and disequilibrium were the most frequent symptoms. The most common findings were ataxia and nystagmus. Gross total resection was performed in 8 patients (27%), subtotal resection in 21 patients (70%), and biopsy in only 1 patient (3%), Tumors were low grade in 73% and high grade in 27%. Twenty-seven patients underwent posterior fossa radiotherapy (median dose, 5400 cGy). Fourteen patients also underwent spinal irradiation (median dose, 3520 cGy). Age was the only significant prognostic factor identified (P <0.01). The 5-year survival rates were 76% for adults and 14% for children. All 14 patients who died had recurrent or residual tumor at the primary site. This review suggests that in patients with primary posterior fossa ependymomas the following is true: 1) the young patient (5 yr old or younger) has a poor prognosis: 2) there was a trend toward a better 5-year survival rate with a gross total resection; 3) if recurrence occurs, it will be at the primary intracranial site; and 4) symptomatic spinal seeding does not occur frequently.

A multicenter study of the prognosis and treatment of adult brain ependymal tumors

“…9,10,15,16,18,19 The findings in the current study (5-year OS, 67%; 10-year OS, 50%) were similar. Results also were comparable with respect to 5-and 10-year FFS rates, which were 43% and 24%, respectively, in the current series and 42-55% and 27-43%, respectively, in the literature.…”

“…Although a clear correlation between age and outcome has not been demonstrated, adult patients appear to exhibit at least a trend toward more favorable prognosis relative to pediatric patients; 5-year survival rates consistently are greater than 50% for adult patients, whereas they range from 14% to 60% for pediatric patients. 9 -13 It also has been suggested that pediatric ependymomas may behave more aggressively because of the immaturity of neural tissue in children 9,13 and that agerelated differences in outcome may be based on differences in cytogenetic aberration patterns between younger and older patients. 14 In addition, considerations regarding side effects and treatment tolerability are quite different for pediatric patients and adult patients.…”

“…Anaplastic ependymoma is even less common in the adult population, accounting for approximately 20% of all ependymal tumors in the current series; this figure is consistent with previously reported rates of 17-28%. 4,9,16,27,28 Due to the limited sample size, solid conclusions regarding survival differences between patients with Grade 2 ependymal tumors and those with Grade 3 ependymal tumors could not be made. In other series, histology was not assessed 16 or was found to be a significant independent predictor of survival only on univariate analysis, 15 which prevented any firm conclusions from being made, due to differences between compared groups in terms of the distribution of prognostic factors.…”

“…Supratentorial ependymomas appear to be associated with less favorable prognosis because they are more likely to exhibit peripheral infiltrative growth into the brain parenchyma and because they are less likely to be entirely encapsulated, rendering surgical resection troublesome. 4,5,9,11,15,30 Furthermore, supratentorial tumors exhibit higher mitotic activity than do infratentorial tumors. 31 Among patient-related factors, age Ͼ 40 years had a negative impact on survival.…”

“…5,9,12,18,19,34 For this analysis, confounding factors included the unreliability of surgical assessment of the degree of ablation 35 and differences in the composition of compared groups with respect to age, performance status, and tumor grade, site, and size. In the current series, as in previous studies, 15,16 no statistically significant difference in overall survival was observed on univariate or multivariate analysis.…”