Neuropathological characteristics of progression after prolonged response to bevacizumab in multifocal hemangioblastoma.

BACKGROUND Antiangiogenic treatment has been explored in few patients with hemangioblastoma after failure of surgery and radiotherapy. CASE REPORT We present the first histopathological follow-up study of a bevacizumab-responsive hemangioblastoma that eventually progressed. For a period of 12 months, therapy with bevacizumab achieved a clinical response and radiological stabilization in a patient with progressive multifocal central nervous system (CNS) hemangioblastoma. Subsequently, selected tumor sites showed radiological progression, in particular, the formation of an intramedullary lesion of the initially predominantly leptomeningeal disease. Histology showed diffuse dural invasion by the hemangioblastoma accompanied with a relatively reduced cell density compared to the preserved vessel structures. CONCLUSION The pattern of progression upon vascular endothelial growth factor (VEGF)-targeting antiangiogenic treatment in hemangioblastoma may involve increased tumor invasiveness.