Benign Ependymomas of the Posterior Fossa in Childhood

Abstract

A series of 22 infants and children with posterior fossa benign ependymomas treated surgically during the past 12 years is presented. All patients were operated on with posterior fossa craniotomy: visible total resection in 10, subtotal resection in 9, partial resection in 2 and biopsy only in 1. One patient (4.5%) died shortly after surgery. Only 5 patients had documented infiltration of the floor of the fourth ventricle. Postoperative radiotherapy was administered with variable radiation fields and doses. Two out of six patients who had total resection and postoperative radiation therapy did not show recurrence during at least 26 months follow-up period. However, patients with incomplete tumor resection almost invariably developed recurrence. An attempt should be made to remove posterior fossa ependymomas totally at the initial craniotomy. The risk periods for recurrence were between 1 and 2 years after subtotal resection and between 2 and 3 years after total resection. In our experience, gross recurrent tumors appear to be resistant to chemotherapy, and a combination of surgery and radiation therapy does not necessarily prevent recurrence. Newer agents or protocols of adjuvant chemotherapy are needed to explore.

Prognostic Factors in Childhood Intracranial Ependymomas: The Role of Age and Tumor Location

“…Other series confirmed a poor outcome for posterior fossa ependymomas [12,21,26,39], suggesting that tumor location is important in limiting surgical removal and, consequently, affecting the outcome. In particular, considering fourth-ventricle ependymomas, which in our study accounted for 60% of the tumors, in some series most of the tumors seem to arise in the vestibular area or the lateral recess [8,43]. We confirm these data, with 81% of posterior fossa ependymomas arising from the lateral recess of the fourth ventricle.…”

“…As pointed out by Tomita et al [8] patients with incomplete tumor removal almost invariably developed recurrence, so an attempt should be made to remove ependymomas totally at the initial craniotomy, especially those of the posterior fossa. Failure, in fact, usually occurs Pediatr Neurosurg 1998;28:135-142 Sala/Talacchi/Mazza/Prisco/Ghimenton/ Bricolo at the primary site, so that the inability to control local disease appears to be the main factor leading to treatment failure [5, 9, 11, 12, 14-16, 21, 34]: a patient with residual tumor is 5.3 times more likely to suffer from disseminated disease [35].…”

“…These tumors develop preferentially in the posterior fossa [8], where they arise from the fourth ventricle ependymal cells. The prognosis remains poor, regardless of the introduction of radiotherapy and/or chemotherapy in the treatment protocol.…”

“…Radical resection, however, may be limited by the location of the tumor, especially for ependymomas arising from the fourth ventricle [8,19,27]. Finally, the degree of malignancy, once ependymoblastomas are excluded, seems to be less important in affecting survival in ependymomas than in astrocytic tumors [28][29][30].…”

The Role of Chemotherapy inNewly Diagnosed Ependymoma of Childhood

“…The prognosis for children with ependymoma remains poor, with overall 5-year survival estimated at approximately 30-50% [1][2][3][4][5][6][7]. It is clear that those patients who experience complete surgical excisions do significantly better versus those with incompletely resected tumors [3,[5][6][7].…”