Radiology Quiz 19315 | Radiopaedia.org

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Where do most spinal ependymomas occur?

Cervical cord is the most common site with roughly 50% located purely within the cervical cord, a further 25% at the cervicothoracic junction and the remainder solely in the thoracic cord.

Question 2

In which phakomatosis are ependymomas frequently encountered?

Show Answer

There is an increased incidence with neurofibromatosis type 2.

The patient went on to have a laminectomy and excision of the tumour.

Histology

MICROSCOPIC DESCRIPTION: Sections show a moderately cellular glial tumour. The tumour comprises a mixed population of cells, some showing glial features with fibrillary processes, yet others displaying more epithelioid features. There is a prominent population of cells showing signet ring cell like features. Many perivascular pseudorosettes are seen. No mitotic figures are identified and there is no necrosis or endothelial cell hyperplasia.

The tumour cells are strongly GFAP positive, show punctate dot like cytoplasmic staining for EMA, and membranous staining for CD99. The Ki-67 proliferative index is less than 1%.

FINAL DIAGNOSIS: The morphological and immunohistochemical features are of ependymoma (WHO Grade II)