Case report of adult-type diffuse high-grade glioma IDH-wildtype subtype E with secondary spinal leptomeningeal dissemination, prolonged survival and literature review.

OBJECTIVES

We report the case of an adult-type diffuse glioma with spinal leptomeningeal dissemination, corresponding to a new molecularly methylation class, identified as "Adult-type diffuse high-grade glioma, IDH-wildtype, subtype E," using the Heidelberg Epignostix CNS Tumor Classifier v12.8.

METHODS

Clinical, histo-molecular, cerebrospinal fluid analyses and neuro-radiological data were recorded.

RESULTS

A 43-year-old man was diagnosed 5 years ago with a diffuse glioma and subsequent spinal leptomeningeal dissemination. He received radiochemotherapy based on temozolomide followed by monthly temozolomide (6 months) but relapsed 15 months later. After three additional therapeutic lines, bevacizumab was introduced, achieving a clinical and imaging response with subtotal regression of lesions. To date, glioblastoma remains under control, 5 years after diagnosis and 3 years after bevacizumab introduction.

DISCUSSION: We describe an unusual prolonged response to bevacizumab in a new subtype of adult-type diffuse high-grade glioma, with spinal leptomeningeal dissemination. Despite frequent dreadful prognosis in patients treated for high-grade gliomas, there are rare long-term responder patients. This situation remains unclear, particularly in the context of spinal leptomeningeal dissemination. The identification of new subtypes could help differentiate between miscellaneous prognostic group. It would be relevant to consider these subgroups in future clinical trials.