Clinical and Radiological Differentiation of Thoracic Spinal Meningiomas and Schwannomas: Insights From the Sapporo-Iowa Joint Study

Abstract

Objective: Meningiomas and schwannomas are the most common intradural extramedullary spinal tumors, but differentiating between them remains challenging. This study aimed to identify clinical and growth pattern differences between the 2 thoracic spinal tumors beyond previously reported imaging signs.

Methods: We retrospectively reviewed 114 patients with histologically confirmed thoracic spinal meningiomas (n = 74) and schwannomas (n = 40) from the Sapporo-Iowa Joint Study. Demographics, clinical symptoms, tumor location, imaging findings (dural tail sign, ginkgo leaf sign, cyst), tumor volume, and spinal cord compression metrics were analyzed.

Results: Meningiomas demonstrated a higher female predominance (88% vs. 48%, P < 0.001) and older mean age at onset (69.2 vs. 59.4 years, P < 0.001). Schwannomas were more frequent in the lower thoracic spine (80%, P < 0.001). The dural tail sign was more common in meningiomas (53% vs. 20%, P < 0.001), whereas cysts occurred exclusively in schwannomas (35%, P < 0.001). Motor deficits were more frequent in meningiomas (91% vs. 55%, P < 0.001), whereas pain predominated in schwannomas (83% vs. 28%, P < 0.001). Schwannomas had a larger median volume but caused less cord compression. Multivariate analysis identified 3 independent predictors for schwannoma: pain (odds ratio [OR], 12.1), lower thoracic location (OR, 9.67), and tumor height (OR, 1.30). A scoring system based on these predictors showed strong diagnostic performance (area under the curve = 0.874).

Conclusions: Thoracic spinal meningiomas and schwannomas exhibit distinct clinical and radiological profiles. The proposed scoring system may support preoperative differentiation and decision-making.

Keywords: Meningioma; Predictive factors; Schwannoma; Thoracic spine.