Delayed Cerebrospinal Fluid Leakage After Treatment of Skull Base Tumors: Case Series of 9 Patients

Introduction: Cerebrospinal fluid (CSF) leaks usually happen in the early postoperative period. However, delayed CSF leak can happen several years after treatment. The purpose of this study was to review the characteristics and clinical course of delayed CSF leak after treating skull base tumors.

Methods: We treated 9 patients with delayed CSF leak (occurring at least 3 months after treatment) between December 2015 and February 2018. Clinical data including initial treatment modality for skull base tumor, time between treatment and CSF rhinorrhea, and the result of endoscopic CSF repair were evaluated by retrospective chart review.

Results: Nine patients with delayed CSF leak were evaluated. The mean age was 42.3 ± 5.2 (mean ± SD) years. Six patients with pituitary adenomas, 1 with a Rathke cleft cyst, 1 with a meningioma, and 1 with an osteosarcoma were enrolled. Seven patients (78%) received radiation, and the mean radiation dose was 55.7 ± 2.6 Gy. The median time between the end of treatment for the skull base tumor and CSF rhinorrhea was 137.0 (interquartile range 24-145) months. Seven patients (78%) had meningitis at the time of operation. CSF rhinorrhea was treated with endoscopic reconstruction using a multilayer technique. Meningitis was improved without neurologic sequelae after reconstruction and antibiotic therapy. One patient had recurrence of CSF leak.

Conclusion: Patients with delayed CSF leak are more likely to have a history of radiation and to present with meningitis at diagnosis. Therefore, CSF rhinorrhea should always be suspected, even several years after treatment, if early symptoms of CSF leak develop in patients with a history of skull base tumor.