Extra and Intramedullary Anaplastic Ependymoma in Thoracic Spinal Cord
A 48-year-old woman had experienced a radiating pain on both legs for 6 months. For 1 month before visiting our department, a radiating pain was getting worse and she recognized newly developed lower extremity motor weakness and urinary incontinence. She underwent magnetic resonance imaging (MRI) that showed suspicious IDEM spinal mass which was well-enhanced on T1-weighted image with contrast and iso-signal intensity on T2-weighted image at T7-T9. There were also intramedullary component and cord edema at T9-T10. The mass lesion was well-enhanced under gadolinium administration displacing the cord to opposite side severely (, ). There was no evidence of mass lesion in the other site of central nervous system.\nWe planned the total resection of the intra and extramedullary mass lesions under the laminectomy. When the dura mater was opened, a dark-pink colored and encapsulated extramedullary component of the tumor was observed. The compressed spinal cord was displaced to right side and there were severe adhesion and ill-defined interface between the extramedullar mass and spinal cord. Under microscope, we removed extramedullary component totally, dissected the arachnoid layer around the cord connecting to extramedullary component and attempted to remove the intramedullary component in the spinal cord. However, we stopped resection and left the residual portion of mass lesion on the cord with concern for the risk of neurological deterioration and intraoperative frozen biopsy of the extramedullary component.\nHistological examination revealed a sort of high grade glial tumor. The cells were characterized by high cellularity and nuclear pleomorphism(Hematoxylin-Eosin stain, ×200) and there were perivascular pseudorosettes and microvascular proliferations. The cells presented immunoreactivity for glial fibrillary acidic protein (GFAP) and the S100, but negative for epithelial membrane antigen (EMA) and CD34 (). Ki-67 index was approximately 40%. The final diagnosis was anaplastic ependymoma, WHO grade III.\nPostoperatively, the patient's neurological condition was improved in a lower extremity motor weakness except urinary incontinence. Six weeks after operation, she was planned to perform radiotherapy with 1.8Gy in 28 fractions and total came to 50.4Gy. There was recurrence of the tumor at the ventral epidural space with remnant component at the spinal cord of T8 level on the follow-up MRI just before the initiation of radiotherapy. The mass lesions of T8 level were disappeared and spinal cord atrophy was found on the follow-up MRI after radiotherapy. However, the patient's neurologic condition of the lower extremities was deteriorated again and there were newly developed mass lesions at the lumbosacral region on the MRI, 14 months postoperatively. It might be CSF dissemination. We recommend further treatment, but she refused.