Introduction: The optimal management strategy for intramedullary spinal cord tumors (IMSCTs) remains controversial, and the impact of radical resection on outcomes is incompletely understood. Additionally, due to the rarity of these lesions, little is known about the genetics and molecular pathogenesis.
Methods: We retrospectively reviewed 33 cases of pediatric and adult patients with IMSCTs who underwent surgical resection, and performed exome sequencing of tumors.
Results: The mean age of patients was 31.4 ± 18.7 years, with 10 (30.3%) pediatric patients. The tumor histologic subtype included ependymoma in 15 (48.5%) cases, astrocytoma in 13 (39.4%) (pilocytic astrocytoma in 4, diffuse in 5, anaplastic in 2, and glioblastoma in 2), hemangioblastoma in 1 (3.0%), oligodendroglioma in 1 (3.0%), and ganglioglioma in 2 (6.1%). A gross total resection (GTR) was achieved in 15 (45.5%) of cases, which was significantly associated with smaller tumor size (p = 0.04), identifiable plane of resection intraoperatively (p < 0.001), and ependymomas (p = 0.002). Only 2 (6.1%) of patients experienced postoperative complications, due to DVTs. In 24 (72.7%) of patients with follow-up data, the mean length of follow-up was 15.7 ± 12.0 months. During this period of time, only 1 (4.2%) patient developed recurrent or progressive disease. At the time of last follow-up, the majority of patients experienced significant improvement in their motor and sensory function and pain compared to their preoperative status. Upon genetic analysis of the tumors, 5 out of 15 (33.3%) of ependymomas displayed mutations in NF2. No recurrent mutations were found in the other histologic types.
Conclusions: Gross total resection of IMSCTs can be performed safely with many patients able to achieve long-term neurologic improvement. Our data confirms the role of NF2 in ependymomas, but suggests that intraspinal tumors are genetically distinct from their intracranial counterparts, and may arise from a divergent disease process.
Patient Care: For patients with these tumors, no standard treatment strategy exists. Radical resection appears to allow for low rates of disease progression and can be performed with few complications, and patients appear to significantly improve with regards to their neurologic status in the long-term. Additionally, the distinct genetic profile of these tumors is informative for understanding the molecular pathogenesis of these tumors and for identifying potential diagnostic, prognostic, and therapeutic biomarkers.
Learning Objectives: Gross total resection of IMSCTs can be performed safely with few complications and with many patients able to achieve long-term neurologic improvement compared to their preoperative baseline. Intraspinal tumors are genetically distinct from their intracranial counterparts, and may arise from a divergent disease process.