Delayed cerebral radiation necrosis after osteoradionecrosis of the skull base: a case report.

Delayed cerebral radiation necrosis (CRN) is a condition characterized by fibrinoid necrosis, blood-brain barrier disruption, and demyelination due to endothelial cell and oligodendrocyte injury as a result of radiation therapy. The presentation is variable as neurologic manifestations depend on the site of the lesion. This case report describes a rare presentation of delayed CRN years after diagnosis and treatment of osteoradionecrosis of the skull base. It highlights the importance of keeping this diagnosis on the differential for patients with a history of radiation therapy to the head or neck who present with new neurological symptoms and/or radiographic findings, even if prior sites of necrosis were treated and there was no subsequent re-irradiation. This report also underscores how CRN is often difficult to distinguish from tumor progression and how assessment of treatment response may help inform the diagnosis.