A case of spinal ependymoma

Clinical History

28-year-old male patient complains of lower back pain since several months.

Imaging Findings

The patient was complaining of low back pain since last several months. X ray of lumbosacral spine reveals mild posterior scalloping in D12-L2 vertebrae with canal widening. MR examination of lumbosacral spine was done using T1, T2 and post contrast sequences in sagittal, coronal and axial planes. Study reveals an approx 11 cm long intraspinal lobulated solid lesion extending from D11 to L2 level which is isointense on T1 and markedly heterogeneous on T2 images with internal small flow voids, due to high vascularization and with isointense T2 and not-Gd enhancing amorphic spots ( myxoid tissue).There is strong heterogeneous enhancement of the tumour mass following gadolinium administration. The conus medullaries is compressed posteriorly by the tumour mass. MR features are suggestive of myxopapillary type ependymoma.

Discussion

Spinal ependymomas are relatively rare tumours, representing less than 5% of all gliomas. They are, however, the most common intramedullary spinal cord tumours, comprising more than 60% of all spinal cord malignancies. Intraspinal ependymomas are typically categorised into 3 groups: intramedullary, myxopapillary and metastatic from an intracranial origin (i.e. drop / metastases).
Intramedullary ependymomas most commonly occur in the cervical and cervico-thoracic part of the spinal cord. The tumours are centrally located and well circumscribed leading to symmetric expansion of the cord. Their arterial supply is most often derived from the anterior spinal artery.
Myxopapillary ependymomas arise almost exclusively in the region of the conus and filum terminale. They account for as many as 90% of tumours in the conus. Rarely, they arise in an extradural post sacral location, presumably from the coccygeal medullary vestige. Unlike the discrete fusiform intramedullary variety, myxopapillary ependymomas primarily appear as lobulated discrete masses that adhere to the filum; secondarily, they appear in the nerve roots of the cauda equina and in the conus. Peripheral haemorrhage and cystic degeneration are frequently present.
To exclude the metastatic variety screening of the entire CNS is mandatory.
Most intraspinal ependymomas arise de novo. Intraspinal ependymomas are believed to arise from the ependymal cells lining the central canal.
The mean age of presentation for intramedullary tumour is 43 years with slight female preponderance, whereas mean age at presentation for myxopapillary ependymoma is 28 years with slight male preponderance.
Patients with intramedullary ependymomas experience neck or back pain (65%) and, less often, numbness or paresthesias. Myxopapillary ependymomas typically cause nonspecific symptoms, most commonly low back pain and lower extremity radiculopathy; much less frequently, lower extremity weakness or bladder dysfunction (20%) is seen. Given the slow growth and the well-circumscribed quality of these tumours, symptoms generally progress slowly, and the tumours are often present in patients long before diagnosis, with an average duration of symptoms before correct diagnosis of 2.4 years.
Most spinal cord ependymomas are iso- or hypointense relative to the spinal cord on T1-weighted MR images. On T2-weighted images, the lesions are typically hyperintense relative to the spinal cord. About 20-33% of ependymomas demonstrate the "cap sign", which is a rim of extreme hypointensity (haemosiderin) seen in T2 images. Virtually all ependymomas enhance strongly following contrast administration.
Ependymomas generally appear as reddish or purple-gray masses with numerous, small, superficial blood vessels. Cysts and haemorrhage are frequently seen. The average number of vertebral segments involved with abnormal signal intensity varies from 3.6 to as many as 15 segments.
Complete surgical resection is the treatment for spinal ependymomas. Total resection is generally curative, without postoperative irradiation. In addition to its role in identifying the tumour, preoperative imaging is essential in planning care. Tumour dissemination precludes surgical cure. Likewise, in the presence of hydrocephalus or a large intracranial mass, the intracranial pathologic condition should be addressed before the spinal lesion is resected.

Differential Diagnosis List

Final Diagnosis

Myxopapillary type - spinal ependymoma.

URL:	https://www.eurorad.org/case/8404
DOI:	10.1594/EURORAD/CASE.8404
ISSN:	1563-4086