Primary Spinal Cord Oligodendroglioma with Postoperative Adjuvant Radiotherapy: A Case Report

Abstract

Primary spinal cord oligodendrogliomas are rare tumors comprising two percent of all spinal cord tumors. Although a treatment guideline has yet to be established, maximal surgical resection is primary in the treatment of spinal cord oligodendrogliomas. Adjuvant radiotherapy has remained controversial, and it is unclear whether chemotherapy adds any benefit. In this case report, the authors present a 24-year-old male who had a seven-year history of left leg weakness and a radiating pain in both legs. Magnetic resonance image (MRI) showed an intramedullary mass at the T4-T8 level. He underwent subtotal removal of the tumor and pathologic diagnosis revealed a WHO grade II oligodendroglioma. The patient was treated with radiotherapy postoperatively and followed up with MRI annually. Clinical and radiological status of the patient had been stationary for four years after the surgery. The five-year follow-up MRI showed an increase in the size and extent of the residual tumor. Despite radiological progression, considering that symptoms and the performance status of the patient had remained unchanged, further treatment has not been performed. Given the clinical outcome of this patient, close observation after subtotal removal with adjuvant radiotherapy is one of the acceptable treatment options for WHO grade II spinal cord oligodendrogliomas.

Keywords: Chromosome 1p/19q co-deletion; MGMT gene promoter methylation; Oligodendroglioma; Radiotherapy; Spinal cord neoplasm.

Fig. 1. Sagittal T1-weighted without contrast (A), T1-weighted with contrast (B), and T2-weighted (C) magnetic resonance image (MRI) of the thoracic spine showing an intramedullary heterogeneous iso T1, high T2, and heterogeneously enhancing lesion located at the T4-T8 level associated with the syrinx extending from T2 to T4. Sagittal computed tomography (CT) images of the thoracic spine without contrast showing focal calcification in the center of the spinal cord tumor (D). Intraoperative photograph showing an edematous and hypervascularized spinal cord with midline effacement (E).

Fig. 2. Histological findings of resected specimens. (A) Hematoxylin and eosin (H&E) staining shows low cellular monotonous round cells with clear cytoplasm(H&E, ×200). (B) Upon glial fibrillary acidic protein immunostaining (GFAP), most cells are negative with some GFAP positive reactive astrocytes (GFAP immunostaining, ×200). (C) The Ki67 labeling index is less than 1% (Ki67 immunostaining, ×200).

Fig. 3. Sagittal T1-weighted with contrast-enhanced MRI of one-year follow up (A), two-year follow up (B), three-year follow up (C), four-year follow up (D), and five-year follow up (E).