Giant cell ependymoma of the thoracic spinal cord.

We report a new case of giant cell ependymoma (GCE) of the thoracic spinal cord. Ependymomas predominate in children and young adults and are frequently intracranial and infra-tentorial. However, a second age peak at 30-40 years is reported for spinal tumours. Microscopically, ependymomas show a large variety of histological features, among which a rare variant with giant cells. This 59-year-old woman presented with a 6-month history of numbness and burning sensation affecting the left lower limb and hemi-trunk. A cervico-thoracic MRI revealed a solid intra-medullary tumour at the level of T1-T3, slightly T1-hypointense, T2-hyperintense and contrast enhancing. A complete surgical resection was carried out through a C7 to T4 laminectomy. Recovery was complete with no sign of recurrence at 18-month follow-up. The initial histological diagnosis of glioblastoma was challenged on the basis of the imaging and operative findings of a well-circumscribed tumour. The case was sent to us for second opinion and we diagnosed a GCE, WHO grade II, with a biphasic pattern including a predominant giant cell component (>90%), with genetic evidence of polyploidy, and a very limited classic component, showing a characteristic loss of chromosome 22. Our report adds to the clinical, imaging, pathological and genetic characterisation of GCE and brings the first genetic evidence that these rare tumours are at least bi-clonal. It also suggests that GCE have a good prognosis after complete surgical resection.