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

Abstract

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