2026 Proffered Presentations
S196: IMAGING AND PATHOLOGIC CORRELATES OF VESTIBULAR SCHWANNOMAS
Elena Kurudza, Resident; Lindsay Hunt; Jeffrey Nadel; Allison Liang; Cody Orton; Sam Tenhoeve; Kyril Cole; Neil Patel; Richard Gurgel; Mana Espahbodi; Robert Rennert; William Couldwell; Qinwen Mao; Karol Budohoski; University of Utah
Introduction: Although vestibular schwannomas (VS) are considered benign lesions, some tumors will progress and result in significant morbidity to the patient including hearing loss, facial nerve dysfunction, hydrocephalus and brainstem compression (Mathies). There is, however, little data regarding the correlations between radiological features, histopathology and tumor behavior to guide treatment.
Objective: The goal of this study was to correlate imaging with histological findings that may indicate more aggressive tumors behavior.
Methods: This was a single-center retrospective study. Histopathological, MRI and clinical characteristics were analyzed and compared to tumor size and treatment outcomes. Univariate and multivariate models were used to determine relevant associations.
Results: 180 patients with diagnosis of VS were included. Larger tumors were more likely to be associated with positive DWI (p = 0.0211), FLAIR (p< 0.0001) and GRE (P<0.0001) signal. DWI and GRE positive tumors were additionally noted to have increased levels of macrophage infiltration (p = 0.0460 and p = 0.0262 respectively). On univariate analysis macrophage infiltration was associated with worse facial nerve outcomes (p = 0.0273) as DWI signal (p = 0.0268) and tumor size (p – 0.0060). On multivariate analysis however, tumor size was the only predictor of facial nerve outcomes (p = 0.0213).
Conclusions: High DWI and GRE signal is associated with tumor size and higher grade features on histologic analysis. While the affect of tumor size on facial nerve outcomes likely overwhelms the influence of macrophage infiltration on predicting outcomes, DWI and GRE signal on surveillance MRI may be useful tools to determine which tumors are at increased risk to growth and progression and ultimately worse facial nerve outcomes. Prospective studies of smaller VSs under surveillance are required to further elucidate these findings.
Figure 1: Representative histopathologic and diffusion weighted imaging findings A. Schwannoma with sheets of macrophage infiltration (3+), B. Schwannoma with no macrophage infiltration (0). Scale bar=100 µm C. Schwannoma without DWI signal. D. Schwannoma with DWI signal (red)