HGG-04. Intramedullary spinal high grade glioma with ALK fusion and excellent response to targeted treatment with alectinib: case report

• Published in: Neuro-oncology (Charlottesville, Va.) Va.), 2022-06, Vol.24 (Supplement_1), p.i60-i60
• Main Authors: Dvir, Rina, Ringel, Amit, Elhasid, Ronit, Constantini, Shlomi, Roth, Jonathan
• Format: Article
• Language: English
• Subjects: High Grade Glioma
• ISSN: 1522-8517; 1523-5866
• DOI: 10.1093/neuonc/noac079.220

INTRODUCTION: Intramedullary spinal cord high grade gliomas are rare pediatric tumors , with a grim prognosis. Current therapeutical strategies include a surgical resection if feasible, and radiotherapy. Additional treatments with various chemotherapy agents have had a minor effect and did not change the course of the disease. New molecular targets are a source of hope. Recent molecular evidence regarding high grade infantile hemispheric gliomas describe specific tyrosine kinase receptor fusions or mutations in ALK, ROS, NTRK and MET domains which may lead to therapeutical targets. There is no data regarding these molecular changes in infantile intramedullary high grade gliomas. We present a two year old girl with a cervical high grade glioma with an ALK mutation which received targeted therapy. CASE REPORT: A two year old girl presented with progressive torticollis and hemiparesis. An intramedullary cervical tumor with ill -defined borders was diagnosed. A limited partial excision was performed and the pathological diagnosis was high grade glioma. Within weeks she developed progressive clinical and radiological deterioration. Molecular studies (Oncomine) revealed an ALK fusion (KIF5B) which was confirmed by immunohistochemistry. Treatment with ALK inhibitor alectinib at 150mg daily was initiated. Torticollis resolved within a week, and MRI after 3 months showed outstanding tumor shrinkage with a small residual mass. There were no adverse events to treatment. DISCUSSION: ALK fusion positive high grade glioma has recently been recognized in infants with hemispheric tumors, and a preliminary recent case report demonstrated excellent response to ALK inhibitors. Intramedullary spinal cord high grade gliomas are rare and harbor poor prognosis. This is the first case of ALK fusion glioma of the spine with excellent preliminary response to alectinib. The duration of treatment and long term prognosis is unknown. Molecular investigations can change the approach to pediatric rare CNS tumors.