J Neurol Surg B Skull Base 2016; 77 - A113
DOI: 10.1055/s-0036-1579900

Preoperative Diagnosis of Vagal and Sympathetic Cervical Schwannomas Based on Radiographic Findings

Kathryn M. Van Abel 1, Christopher S. Graffeo 1, Jonathan M. Morris 1, Jamie J. Van Gompel 1, Eric J. Moore 1, Daniel L. Price 1, Jan L. Kasperbauer 1, Jeffrey R. Janus 1, Kerry D. Olsen 1, Michael J. Link 1
  • 1 Mayo Clinic, Rochester, Minnesota, United States

Objective: Vagus nerve and sympathetic chain cervical schwannomas (VNCS/SCCS) are benign nerve sheath tumors that arise in the head and neck. Despite similar presentations, and therefore difficulty in accurate preoperative diagnosis, the potential morbidity following resection is significantly higher for VNCS. Therefore, the aim of this study was to investigate radiographic diagnostic criteria to facilitate more accurate preoperative diagnoses via a retrospective case series and comparative analysis of the literature.

Methods: Blinded review of imaging studies from retrospectively collected, operatively confirmed VNCS and SCCS. Supportive systematic review of published series reporting patient-specific preoperative imaging findings in VNCS or SCCS is further included.

Results: We identified 9 VNCS and 11 SCCS. In the study cohort, internal carotid artery (ICA)/internal jugular vein (IJV) splaying did not significantly predict nerve-of-origin (p = 0.06); however, medial and lateral ICA displacement were significantly associated with VNCS and SCCS, respectively (p = 0.01; p = 0.003). Multivariate analysis demonstrated that ICA/IJV splaying with medial ICA displacement carries an 86% probability of VNCS (p = 0.001), while absent ICA/IJV splaying with lateral ICA displacement carries a 91% probability of SCCS (p = 0.006).

Our literature review included 25 publications, incorporating a total of 106 patients including the present series. In comparative analysis of the literature, ICA/IJV splaying was significantly but not uniquely associated with VNCS (p < 0.0001); multivariate analysis demonstrated that the combination of ICA/IJV splaying and medial ICA displacement carries a 75% probability of VNCS (p < 0.0001), while absent ICA/IJV splaying and lateral ICA displacement carries an 87% probability of SCCS (p = 0.0003).

Conclusions: ICA/IJV splaying frequently predicts VNCS; however, this finding is also observed commonly in SCCS, and in our study, was observed more commonly than previously reported. When congruent with splaying, medial/lateral ICA displacement significantly enhances the reliability of preoperative predictions, empowering more accurate prognostication.