Stephen James H, Sievert Angela J, Madsen Peter J, Judkins Alexander R, Resnick Adam C, Storm Phillip B, Rushing Elisabeth J, Santi Mariarita
Divisions of Neurosurgery, Children’s Hospital of Philadelphia, PA, USA.
J Neurosurg Pediatr. 2012 Jun;9(6):646-53. doi: 10.3171/2012.2.PEDS11285.
Primary spinal cord ependymomas (EPNs) are rare in children, comprising classical WHO Grade II and III tumors and Grade I myxopapillary ependymomas (MEPNs). Despite their benign histology, recurrences and neural-axis dissemination have been reported in up to 33% MEPNs in the pediatric population. Treatment options beyond resection are limited, and little is known about their tumorigenesis. The purpose of this study was to explore the tumor biology and outcomes in a consecutive series of pediatric patients treated at a single institution.
The authors performed a retrospective clinicopathological review of 19 patients at a tertiary referral children's hospital for resection of a spinal cord ependymoma. The population included 8 patients with a pathological diagnosis of MEPN and 11 patients with a pathological diagnosis of spinal EPN (10 cases were Grade II and 1 case was Grade III). The upregulation of the following genes HOXB13, NEFL, PDGFRα, EGFR, EPHB3, AQP1, and JAGGED 1 was studied by immunohistochemistry from archived paraffin-embedded tumor samples of the entire cohort to compare the expression in MEPN versus EPN.
Gross-total resection was achieved in 75% of patients presenting with MEPNs and in 100% of those with EPNs. The average follow-up period was 79 months for the MEPN subset and 53 months for Grade II/III EPNs. Overall survival for both subsets was 100%. However, event-free survival was only 50% for patients with MEPNs. Of note, in all cases involving MEPNs that recurred, the patients had undergone gross-total resection on initial surgery. In contrast, there were no tumor recurrences in patients with EPNs. Immunohistochemistry revealed no significant differences in protein expression between the two tumor types with the exception of EPHB3, which demonstrates a tendency to be positive in MEPNs (6 reactive tumors of 9) rather than in EPN (2 reactive tumors of 10).
The authors' experience shows that, following a gross-total resection, MEPNs are more likely to recur than their higher-grade counterpart, EPNs. This supports the recommendation for close long-term radiological follow-up of pediatric patients with MEPNs to monitor for recurrence, despite the tumor's low-grade histological feature. No significant difference in the protein expression of HOXB13, NEFL, PDGFRα, EGFR, EPHB3, AQP1, and JAGGED 1 was present in this selected cohort of pediatric patients.
原发性脊髓室管膜瘤（EPNs）在儿童中较为罕见，包括世界卫生组织（WHO）经典的II级和III级肿瘤以及I级黏液乳头型室管膜瘤（MEPNs）。尽管其组织学表现为良性，但在儿科人群中，高达33%的MEPNs有复发和神经轴播散的报道。除手术切除外的治疗选择有限，且对其肿瘤发生机制知之甚少。本研究的目的是探讨在单一机构接受治疗的一系列连续儿科患者的肿瘤生物学特性及治疗结果。
作者对一家三级转诊儿童医院的19例接受脊髓室管膜瘤切除术的患者进行了回顾性临床病理分析。该人群包括8例病理诊断为MEPN的患者和11例病理诊断为脊髓EPN的患者（10例为II级，1例为III级）。通过免疫组织化学方法，对整个队列存档的石蜡包埋肿瘤样本中HOXB13、NEFL、PDGFRα、EGFR、EPHB3、AQP1和JAGGED 1等基因的上调情况进行研究，以比较MEPN与EPN中的表达。
MEPN患者中有75%实现了全切除手术，EPN患者则为100%。MEPN亚组的平均随访期为79个月，II/III级EPN亚组为53个月。两个亚组的总生存率均为100%。然而，MEPN患者的无事件生存率仅为50%。值得注意的是，在所有复发的MEPN病例中，患者初次手术时均已进行了全切除。相比之下，EPN患者未出现肿瘤复发。免疫组织化学显示，除EPHB3外，两种肿瘤类型在蛋白表达上无显著差异，EPHB3在MEPN中呈阳性的倾向更大（9例中有6例反应性肿瘤），而在EPN中则较少（10例中有2例反应性肿瘤）。
作者的经验表明，在全切除术后，MEPN比其高级别对应物EPN更易复发。这支持了对患有MEPN的儿科患者进行长期密切影像学随访以监测复发情况的建议，尽管该肿瘤具有低级别组织学特征。在这个选定的儿科患者队列中，HOXB13、NEFL、PDGFRα、EGFR、EPHB3、AQP1和JAGGED 1的蛋白表达无显著差异。
