Pediatric Myxopapillary Ependymomas Research Articles

EPEN-09. UTILITY OF RADIATION THERAPY IN SPINAL CORD MYXOPAPILLARY EPENDYMOMAS: A REVIEW OF THE LITERATURE

Abstract INTRODUCTION Myxopapillary ependymomas (MPEs) are slow-growing tumors that comprise about 25% of spinal ependymomas. Although historically designated as grade 1, the recent WHO classification has upgraded MPEs to grade 2 given their potential for recurrence and dissemination. While the National Comprehensive Cancer Network guidelines recommend avoiding radiation therapy (RT) unless a gross-total resection (GTR) is not achieved, several reports have suggested a potential benefit of adjuvant RT in improving relapse-free survival in children after GTR. This literature review was conducted to compare available data to determine the utility of upfront irradiation in these patients. METHODS A comprehensive literature review from 1984-2021 was performed on PubMed using keywords: “pediatric myxopapillary ependymoma” and “radiation.” One case was censored for unknown radiation status. RESULTS 17 analyses from 1984-2021 were reviewed, yielding 140 pediatric cases of MPE, of whom 59% (n=83) received a GTR. Of those that received a GTR, average age was 13.7 yrs (range, 6-21), and 66% were male. The most common location was lumbosacral (25%), followed by thoracolumbar (19%). 22.8% (n=19) of patients received upfront focal RT. Relapse occurred in eight (42%) patients who received upfront RT, and 30 (47%) of those who did not, with no clear age or gender discrimination in those that relapsed. Distant recurrence occurred in 75% of those who received RT, and 68% of those that did not. The duration of event-free survival will be included in the final presentation. CONCLUSIONS While some individual studies have suggested a survival advantage in pediatric MPE after focal RT, in this meta-analysis, both relapse rate and location seemed similar regardless of receipt of RT. From this available evidence, the efficacy of upfront RT has not been demonstrated.

Pediatric Myxopapillary Ependymomas: A Clinicopathologic Evaluation.

Myxopapillary ependymomas (MPEs) have an indolent clinical course, corresponding to World Health Organization Grade I. A total of 13 pediatric MPEs have been reported in the literature with "anaplastic features," including elevated proliferative activity (≥5 mitoses/10 high-power fields), necrosis, and microvascular proliferation. No consensus exists regarding the prognostic significance of such features. A retrospective clinicopathologic review of pediatric MPEs diagnosed between 1996 and 2018 at Mayo Clinic was performed. Totally, 8 pediatric MPEs (6 male; age: 7.52 to 16.88 y) were identified. Totally, 3 had disseminated disease at presentation. All patients underwent surgical resection (7 gross total; 1 subtotal). Totally, 5 cases harbored ≥5 mitoses/10 high-power fields (range: 5 to 9), 3 of which showed necrosis (2 with disseminated disease). Postsurgery, 2 patients received radiation; one with disseminated disease and another with increased mitotic activity/necrosis; neither has recurred (follow-up: 1.18 and 3.19 y). In all, 2 patients with disseminated disease, elevated mitotic activity, and necrosis had new metastatic disease/progression of nonresected metastatic foci (2.6 and 26.8 mo), received radiation therapy, and remain progression free (3.01 and 9.34 y). All patients are alive (median follow-up 1.31 y, range: 0.66 to 11.75). Among pediatric MPEs, the concurrent presence of elevated mitotic activity and necrosis may be associated with an aggressive clinical course, warranting closer surveillance and consideration of adjuvant therapies.

Spinal Seeding Metastasis of Myxopapillary Ependymoma: Report of Three Pediatric Patients and a Brief Literature Review

Objective: Myxopapillary ependymomas (MPEs) in children are rarely reported low-grade glial tumors; however, MPEs sometimes possess malignant characteristics such as spinal seeding/drop metastasis (SSM). We aimed to present 3 pediatric MPE cases that experienced SSM at 2 neurosurgical centers. Materials and Methods: We retrospectively reviewed the medical records of 38 primary spinal MPE cases who underwent surgery at 2 neurosurgical centers spanning 16 years, from 2004 to 2019. All pediatric cases (patient age <18 years) who were diagnosed with MPE and re-presented with SSM were selected as the core sample for this study. Relevant literature was briefly reviewed. Results: Three pediatric MPE cases (2 females and 1 male) experienced SSM. The mean age at first presentation was 12.0 ± 1.0 years. The mean preoperative course was 2.9 ± 1.2 months. The predominant location was the lumbar spine in 2 tumors (both originated from terminal filum [TF]). Two tumors were located intradural intramedullary. Gross-total resection was achieved in 2 patients. No patient had neurofibromatosis type 2. No adjuvant treatment was given after the first surgery. The mean period between the first diagnosis and diagnosis of SSM was 44.0 ± 31.5 months. The location of SSM in all patients was the sacral spine (1 patient experienced distant metastasis in her brain besides her sacral metastasis). The mean follow-up was 68.3 ± 53.7 months. Conclusions: We found a statistically significant relationship between SSM in pediatric MPEs and the intramedullary location, TF origin, and number of affected segments. Close clinical and radiological follow-up is essential for pediatric MPE patients.

Long-Term Surgical Resection Outcomes of Pediatric Myxopapillary Ependymoma: Experience of Two Centers and Brief Literature Review

Myxopapillary ependymoma (MPE) is a rarely reported lesion of the spinal cord in the pediatric population. Based on their low mitotic index and slow-growth, MPEs are classified as low-grade glial tumors. However, MPEs have malignant characteristics, such as distant neural axis and extraneural axis dissemination. We present the long-term surgical resection outcomes of 5 consecutive pediatric MPE cases and the results of a literature search for reported cases of pediatric spinal MPE. We retrospectively reviewed the medical records of 38 primary spinal MPE cases who underwent surgery at 2 neurosurgical centers over a 16-year period from January 2004 to January 2019. All pediatric cases (age <18 years; n= 5) who were diagnosed with MPE composed the core sample for this study. This series comprised 5 patients (3 females and 2 males), with a mean age at first presentation of 13.6 ± 2.3 years. The mean preoperative course was 8.2 ± 9.3 months. The predominant location was the lumbar spine, for 4 tumors. Gross total resection (GTR) was achieved in 4 patients. All patients were diagnosed histopathologically as MPE, World Health Organization grade I. No adjuvant treatment was provided after the first surgery. Three patients experienced spinal drop metastasis. The mean interval between the first diagnosis and diagnosis of neural dissemination was 44.0 ± 31.5 months. The location of neural dissemination in all patients was the sacral spine; 1 patient experienced distant metastasis in the brain along with her sacral metastasis. The mean duration of follow-up was 75.0 ± 37.6 months. Even with GTR, pediatric MPE has a high propensity for neural axis dissemination. We recommend close clinical and radiologic follow-up for pediatric patients with MPE.

Myxopapillary ependymomas in children: imaging, treatment and outcomes

Myxopapillary ependymomas (MPEs) are rare spinal tumors in children. The natural history and clinical course of pediatric MPEs are largely unknown and the indication for adjuvant therapy remains to be clarified. We performed an IRB-approved, retrospective review of children with MPEs treated at the Dana-Farber/Boston Children's Cancer and Blood Disorder Center between 1982 and 2013. Eighteen children (age range 8-21 years, median age 14 years) met inclusion criteria. We reviewed the histopathology, magnetic resonance imaging, tumor location and stage, surgical management, adjuvant therapy, and clinical outcomes. The median follow-up duration was 9.4 years (range 1-30 years). Children most commonly presented with pain, scoliosis, and urinary symptoms. All primary tumors were located in the lower thoracic or lumbar spine. Nine children (50%) had leptomeningeal tumor seeding at presentation, most commonly located within the distal thecal sac. A gross-total resection was achieved in nine children (50%). Three children were treated with irradiation following initial surgery. No child received adjuvant chemotherapy at diagnosis. The 10-year event-free survival (EFS) was 26% ± 14.8. Children with disseminated disease trended towards inferior EFS compared to those with localized disease (10-year EFS 12.7% ± 12 vs. 57 ± 25%, p value 0.07). The 10-year overall survival was 100%. The efficacy of adjuvant irradiation could not be assessed due to the small sample size. Although children with MPEs frequently present with disseminated tumor and/or develop recurrent or progressive disease, their overall survival is excellent. Treatment should aim to minimize both tumor- and therapy-related morbidity.

A retrospective analysis of the patterns of failure in pediatric myxopapillary ependymoma

Objective Myxopapillary ependymoma (MPE) is a rare tumor, accounting for 10–20 % of pediatric intramedullary spinal cord tumors. Our objective was to study the patterns of dissemination and failure in pediatric MPE.

Management of Pediatric Myxopapillary Ependymoma: The Role of Adjuvant Radiation

Myxopapillary ependymoma (MPE) is a distinct entity most frequently presenting in the lumbosacral region of the spinal cord. This tumor is rare in children with the majority of publications and treatment recommendations based on adult patients. The primary treatment of choice is gross total resection (GTR) with no clearly defined role for adjuvant radiation therapy. Published reports suggest that children with MPE present with a more aggressive disease course with higher rates of both local failure and distant metastasis. The goal of this study is to assess the role of adjuvant radiation therapy (RT) in pediatric myxopapillary ependymoma. Sixteen pediatric patients with histologically confirmed myxopapillary ependymoma seen at Johns Hopkins Hospital between November 1984 and December 2010 were retrospectively reviewed. Fifteen boys and one girl with a median age of 16.5 years (range 12 - 21 years) were initially identified of whom fifteen patients were evaluable. Descriptive statistics were used for analysis. All patients received surgery as the initial treatment modality. Five patients received surgery alone and 10 patients received RT given as either adjuvant therapy or as salvage at the time of recurrence. The median total dose of radiation was 50.4 Gy (range 48.6 - 54 Gy) delivered to the involved field. After a median follow up of 8.4 years (range 0.3 - 26.2 years), all patients in this study were alive with stable disease. 50% of patients receiving surgery alone were progression-free at 5 years compared to 66.7% receiving RT. Patients treated with surgery alone had a median progression-free survival (PFS) of 3.5 years compared to patients treated with adjuvant RT who had a median PFS of 8.8 years. Specifically, patients treated with GTR had a median PFS of 4 years compared to a median PFS of 7.1 years in patients treated with GTR and RT. Of the patients receiving surgery alone, 43% developed local recurrence. In contrast, no patient who received adjuvant RT failed locally. Two patients treated with RT experienced grade 2 toxicity and four reported grade 1 toxicity. No late toxicity was reported at last follow-up. Neurologic symptoms either improved or remained stable following surgery and/or radiation in all patients. The results of this study demonstrate that adjuvant RT can improve local control and progression free survival compared to GTR alone. Adjuvant RT should be considered following surgical resection in pediatric patients with myxopapillary ependymoma.

Adjuvant radiotherapy in the treatment of pediatric myxopapillary ependymomas

Assess the role of radiotherapy (RT) in the management of primary and recurrent myxopapillary ependymoma (MPE). We conducted a retrospective review of patients with MPE treated at the Montreal Children's Hospital/McGill University Health Centre between 1985 and 2008. Seven children under the age of 18 were diagnosed and treated for MPE. All patients were treated with surgery to the primary site. Three patients underwent subtotal resection (STR) and received adjuvant post-operative RT. Only one patient who had spinal drop metastases received post-operative RT to the lumbosacral region following complete resection of the primary tumor. After a median follow up of 78 months (range 24-180 months), all patients were alive with controlled disease. The single patient treated with gross total resection (GTR) and adjuvant local radiation remained recurrence free. One of the three patients treated with STR and adjuvant RT had disease progression that was controlled with re-resection and further RT. Two of the three patients treated with surgery alone developed local and disseminated recurrent spinal disease that was controlled by salvage RT. Our data support the evolving literature which suggests that GTR alone provides suboptimal disease control in MPE. In our patients, RT resulted in control of residual, metastatic and/or recurrent disease. Routine adjuvant RT may improve outcomes in pediatric MPE.