Answer of December 2009

Clinical History:

A 45-year-old gentleman with good past health presented with progressive left-sided weakness and bilateral hand clumsiness for a few months.  He has no headache, no diplopia nor swallowing problem. On neurological examination, a neurologically sound patient was found to have muscle wasting over bilateral first dorsal interossei, increase tonicity of bilateral lower limb and the presence of left ankle clonus. Limb power is diminished with MRC grading 4/5 over left upper and lower limbs.  MRI spine was performed.

                           Fig 1. T2 Sagittal                                                        Fig 2. T2 Axial

                                                                                                Fig 4. Postcontrast T1 Sagittal with 

                             Fig 3. T1 Sagittal                                                          fat saturation

Diagnosis:

Ependymoma of spinal cord

Discussion:

MR Images of this patient show a T1W hypointense and T2W hyperintense expansile intramedullary mass present in the spinal cord between C6 and T1 vertebral levels. It demonstrates relatively homogeneous contrast enhancement with evidence of haemosiderin deposition. Features are suggestive of ependymoma of the spinal cord.

Ependymoma of spinal cord is the most common intramedullary spinal neoplasm in adult. It commonly affect cervical cord alone (44%)/with extension into thoracic cord (23%) and thoracic cord alone (26%). Patients usually present with back or neck pain, sensory or motor deficits, bowel or bladder dysfunction. It has a long antecedent history of about 37months due to slow tumor growth. It can also metastasis to lung, retroperitonium and lymph nodes.

MRI of the spinal cord often reveals an iso-/hypointense (rarely hyperintense from haemorrhage) on T1WI and a hyper-/isointense centrally locating cord mass on T2WI. “Cap sign” may be present showing an extremely hypointense rim at the tumor poles on T2WI due to haemosiderin deposits from prior haemorrhage. On contrast study, it shows mostly intense homogeneous enhancement.

Surgical intervention was performed on this patient. Left C6-T1 hemi-laminectomy and near total excision was done. Intra-operatively it found a 5 cm long cystic intra-medullary tumor at C6-T1 level. Final pathology reveals an ependymoma of at least WHO grade II. He is planned for further radiotherapy.