Characteristics of thoracolumbar intramedullary subependymomas.

OBJECT Thoracolumbar intraspinal subependymomas are very rare intramedullary low-grade tumors. The authors report on the clinical and morphological features of 2 cases of thoracolumbar intraspinal subependymomas and provide midterm follow-up data. METHODS The clinical and radiological profiles of 2 patients with progressive spinal cord dysfunction due to thoracolumbar intraspinal subependymomas were retrospectively studied and compared with previously reported cases. RESULTS Patients with intraspinal subependymomas initially presented with back pain and long-tract signs. The tumors were hyperintense on T2-weighted MR imaging, isointense on T1-weighted imaging, and noncontrast enhancing. Within 1 of the tumors, a medial septum was present on axial T2-weighted imaging. The tumors were intramedullary but grew exophytically and were amenable to gentle surgical separation from normal neural structures. Therefore, gross-total resection was feasible, and neurological outcome was good. No further adjuvant therapy was conducted. On follow-up (at 58 and 18 months, respectively), no tumor recurrence was observed. CONCLUSIONS Symptomatic thoracolumbar intraspinal subependymomas with a distinct appearance on MR imaging are amenable to complete excision with favorable neurological outcome. In this study no tumor recurrence was observed at midterm follow-up in either patient, neither of whom underwent adjuvant therapy.