Poster Presentation Joint 2016 COSA and ANZBCTG Annual Scientific Meeting

Angiocentric glioma transformed into anaplastic ependymoma. Evidence of a pleomorphic tumour capable of ependymal and glial transformation? (#245)

James McCracken 1 , Michael Gonzales 2 , Pramit Phal 2 , Kate Drummond 2
  1. St Vincent's Health, Hawthorn East, VIC, Australia
  2. Melbourne Health, Hawthorn East, VIC, Australia

Angiocentric glioma (AG) is a low grade glioma, that was first described in 2002. Since this description, 83 cases of 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.These include transformation of an AG into an anaplastic astrocytoma, AG with a high proliferative index, and several reports of AG with mixed histology. These include glioblastoma, high grade glioma, astroblastoma, a large calcified cystic lesion, ganglioglioma and other cystic appearances. Given the small number of AG reported to date, and therefore an incomplete picture of its natural history, the emerging picture could be that of a usually benign epileptogenic tumour, with malignant potential, similar to that of a pleiomorphic xanthoastrocytoma [30]. The reported cases of AG and malignancy are shown in table 1.

 

We add to the literature a case of a 16 year old female who presented in May 2011 with a 3 month history of complex partial seizures, with MRI showing a T2 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 6 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 19 years.