Introduction: Surgical resection is generally recommended for cervicomedullary tumors, but morbidity of resection may be significant. This study sought to identify MRI characteristics that might predict morbidity and extent of resection.
Materials and methods: A retrospective review was performed of MRI findings, histopathology, extent, and morbidity of resection in cervicomedullary gliomas undergoing resection during 1985-2008.
Results: Of 78 brainstem tumors, nine cervicomedullary tumors undergoing resection were identified: two pilocytic astrocytomas, two gangliogliomas, and five grade II astrocytomas. Mean age was 6.3 years (range 1.7-11.2 years). Initial treatment was surgery in seven: biopsy (1), <25% resection (4), and 25-50% resections (2). Bulbar worsening occurred in five of six patients with interposed areas of non-enhancement versus one of three patients without interposed non-enhancing tissue (P = 0.014). Additionally, bulbar worsening occurred in five of five patients with a poorly defined tumor/brainstem interface and abnormal low T1 signal extending beyond obvious tumor into the brainstem versus one of four with a well-defined tumor margin (P = 0.008). Following chemo- or radiotherapy, the definition of the brainstem/tumor interface improved. In four patients undergoing surgery after chemo/radiotherapy, more extensive resections were achieved without neurologic worsening: >80% in three and 30% in one.
Conclusion: A less aggressive initial surgical approach, supplemented by postoperative chemotherapy, designed to preserve brainstem function, is proposed for patients with interposed non-enhancing tissue continuous with normal cervical cord or medulla and/or a poorly defined ventral tumor/brainstem interface with abnormal low T1 signal extending beyond obvious tumor into the brainstem.