Angiocentric glioma transformed into anaplastic ependymoma: Review of the evidence for malignant potential.

Angiocentric glioma (AG) is a low grade glioma, that was first described in 2002. Since this description, 83 patients with AG have been described, including ours. AG typically presents in childhood with medically refractory seizures that are cured with gross surgical resection. Whilst the natural history is that of a benign tumour, there have been reports of recurrence, transformation, and malignant features that suggest that AG is potentially malignant. We add to the literature a case of a 16-year-old girl who presented in May 2011 with a 3-month history of complex partial seizures, with MRI showing a T2-weighted hyperintense lesion in the left insula and inferior frontal lobe. This was confirmed on biopsy as AG and was followed with surveillance imaging. In April 2012, she presented with disease progression and underwent a left temporal lobectomy, with histology showing both AG and grade II astrocytoma. Adjuvant radiotherapy of 50 Gray in 28 fractions was administered. A small area of contrast enhancement appeared in the left parietal lobe in December 2012, which progressed over subsequent months. In June 2013, she underwent a near total excision, with histology showing anaplastic ependymoma. She received six cycles of adjuvant temozolamide. Despite this, the tumour continued to progress, with her seizure control deteriorating, and the development of a right hemiparesis. The patient died in January 2014, aged 19years.