Long-term Follow-up with MRI Scans After Enucleation of Peripheral Nerve Schwannomas: Results from a Single-center Case Series

Abstract

BackgroundEnucleation is a surgical technique to resect peripheral nerve schwannomas. The procedure has a low risk for postoperative deficit, but a small chance for recurrence, because tumor cells may remain inside the pseudocapsule that is left after resection. MRI scans are frequently performed after surgery to investigate potential residual tumor, but currently there is little information in the literature on the value of follow-up with MRI. Material and methodsAll patients that underwent enucleation of a peripheral nerve schwannoma between October 2013 and June 2022 were included. Postoperative MRI scans (Gadolinium enhanced) made at different time-points after the surgery were re-examined for residual enhancement. Patients with residual enhancement were contacted to inform whether symptoms had recurred. ResultsA total of 75 schwannoma enucleations in 74 patients were included. The first postoperative MRI scan, performed three months after the surgery, showed no residual enhancement in 50 patients. In the remaining 24 patients, another MRI scan was made one year after the surgery, which still showed a possible remnant in 11 patients. On the third MRI scan, performed two years after enucleation, there were seven suspected cases (9%). None of these patients had clinical symptoms at a mean postoperative follow-up of five years. ConclusionsOur data shows that the value of postoperative MRI scans after enucleation of peripheral nerve schwannomas is limited, because residual enhancement in the beginning can be non-specific and the small percentage of patients, that persistently had a potential remnant, were all asymptomatic.