Flap Reconstruction and Hyperbaric Oxygen Therapy in the Management of Temporal Bone Osteoradionecrosis in an Endolymphatic Sac Tumor: Case Report

Endolymphatic sac tumors (ELSTs) are rare neuroectodermal neoplasms arising within the posterior petrous bone. We present a case of a 21-year-old man who presented with a 6-month history of intermittent morning headaches, fatigue, diplopia, and gait ataxia. Imaging and surgical pathology identified an adenocarcinoma of the endolymphatic sac compressing the cerebellum and brain stem. The tumor and multiple metastases were treated with surgery, radiation, and radiosurgery. Following insertion of a ventriculoperitoneal shunt for hydrocephalus, he developed symptomatic tension pneumocephalus secondary to radionecrosis of his petrous bone, requiring flap reconstruction and use of a programmable shunt valve complemented by hyperbaric oxygen (HBO) therapy. We document here a young patient with a rare adenocarcinoma of the endolymphatic sac. This case is unique for its initial presentation without any vestibuloauditory symptoms. Metastatic spread of ELSTs is also rare. While osteoradionecrosis (ORN) of the temporal bone has been reported previously in patients with nasopharyngeal carcinoma, this is the first time it has been presented in the context of an ELST. Tension pneumocephalus is a rare complication of skull base ORN. This is the first reported use of a programmable shunt valve and HBO therapy in the management of tension pneumocephalus.