Spinal schwannoma with broad pial adhesion: A case report

Background: Typical spinal schwannomas are well-encapsulated intradural extramedullary tumors arising from sensory nerve roots. Schwannomas adherent to the spinal cord are rare and include both intramedullary (subpial) and combined intra- and extramedullary lesions. Here, a 60-year-old male initially presented with a combined intra/extramedullary schwannoma with dense adhesions to the spinal cord; at surgery, this proved to be a peripheral schwannoma with broad pial adhesions. Case Description: A 60-year-old male presented with severe paraparesis attributed to a dorsal thoracic T11 tumor. Chronic hemodialysis precluded performing a contrast magnetic resonance. Intraoperative ultrasonography showed a well-defined, multi-cystic, and dorsal lesion without intramedullary extension. After dural opening, the tumor was tightly adherent to the dorsal spinal cord/pia. A staged internal decompression improved tumor mobility, allowing the tumor to be progressively dissected away from its broad-based pial adhesion/vasculature. Finally, a clean cleavage plane between the tumor capsule and spinal cord confirmed that the tumor was an extramedullary, broad-based pial schwannoma that was totally resected without neurological sequelae. Conclusion: Peripheral spinal schwannomas may occasionally exhibit broad-based pial adhesions that mimic intramedullary (subpial) or combined intra/extramedullary lesions. Proceeding with a step-wise resection often reveals an increasingly clean cleavage plane facilitating gross total tumor resection.