Spontaneous cerebrospinal fluid rhinorrhea secondary to anterior fossa osteoradionecrosis.

Osteoradionecrosis (ORN) after radiation therapy of head and neck or brain tumor most often presents in the mandible, followed by the maxillary bone. This case report describes a patient who presented with spontaneous cerebrospinal fluid (CSF) rhinorrhea 12 months after conventional external beam radiotherapy for frontotemporal anaplastic astrocytoma, and was diagnosed with anterior fossa ORN. Osteolysis in the anterior fossa on CT scan confirmed the diagnosis. A prompt temporal muscle graft with pericranial flap seal treated both the ORN and the CSF rhinorrhea, but observation would have been a suitable conservative option if ORN presented without CSF rhinorrhea.