Thoracic subpial intramedullary schwannoma involving a ventral nerve root: a case report and review of the literature.Surg Neurol. 2005 Apr; 63(4):389-93; discussion 393.SN
Subpial intramedullary schwannoma of the spine is a rare tumor. A few case reports have revealed that the tumor originates from around the ventral nerve exit zone, with only one case confirming involvement of the ventral root.
A 72-year-old female with a 10-month history of Brown-Sequard-type monoparesis is described. On neurological examination, the left leg motor function was grade 3 or 4/5, and dysthesia with low pinprick sensation at the right side below the T8 and T9 dermatome was identified. There were no signs of multiple neurofibromatosis. Magnetic resonance imaging demonstrated a well-demarcated round mass with high enhancement and moderate peritumoral edema, but no combined syrinx. The mass (1.5 x 1 x 1.5 cm) was located at the anterior part of the spinal canal on the left of the midline of the T8 and T9 space. A left-sided unilateral approach was performed with osteoplastic laminotomy of T8 and T9 vertebrae, and radical removal of a subpial tumor was achieved. Pathological examination revealed subpial intramedullary schwannoma. The patient improved postoperatively and at discharge was able to walk without any support.
The authors emphasize that the differential diagnosis of intramedullary schwannoma should be included when peritumoral edema is moderately present to provide appropriate preoperative preparations, even if a tumor is seemingly located in the intradural extramedullary space.